Acne Sensitive Cream

Overview of Acne Sensitive Cream

Dosage Strength of Acne Sensitive Cream

Azelaic Acid / Niacinamide / Zinc Pyrithione 4/4/0.3% 30 mL Pump

General Information

Azelaic Acid

Azelaic acid is a topical anti-acne agent. Azelaic acid is a naturally occurring dietary constituent (whole grain and animal products) and can be formed endogenously from longer-chain dicarboxylic acids, metabolism of oleic acid, and omega-oxidation of monocarboxylic acids. Azelaic acid is used as a treatment for acne vulgaris and is one of the leading treatments for this condition in Europe where it has been marketed as a 20% cream since 1989 by Schering. The drug is also effective for reducing the number of inflammatory pustules and papules associated with rosacea. Reduction in erythema may occur; however, efficacy has not been established for erythema associated with rosacea without papules and pustules. Azelaic acid has been administered orally and intravenously; however, only a topical formulation is marketed in the United States. The drug was originally FDA approved as a 20% cream for the treatment of acne vulgaris in September 1995; several brand name creams are now available. A 15% topical gel and foam were FDA-approved for the treatment of rosacea in December 2002 and July 2015, respectively.123

Niacinamide

Niacin (nicotinic acid or 3-pyridinecarboxylic acid) is a B-complex vitamin. Good dietary sources of niacin are animal proteins, beans, green vegetables, liver, mushrooms, peanuts, whole wheat, and unpolished rice. Niacin is also present in cereal grains but is largely bound to plant proteins, and thus is poorly absorbed after ingestion. Niacin is one of the substances used in the enrichment of refined flour, and our dietary intake of pre-formed niacin comes primarily from enriched grains. However, the body's niacin requirement is also met by the biosynthesis of niacin from tryptophan, an amino acid. For example, milk and eggs do not contain niacin, but do contain large amounts of tryptophan from which niacin is derived. Each 60 mg of excess tryptophan (after protein synthesis) is converted to approximately 1 mg of niacin. Synthesis of the vitamin from tryptophan in proteins supplies roughly half the niacin requirement in man. Iron-deficiency or inadequate pyridoxine or riboflavin status will decrease the conversion of tryptophan to niacin and may contribute to deficiency, due to an interdependence of coenzymes in the niacin production pathway. A late and serious manifestation of niacin deficiency is pellagra, a clinical symptom complex principally affecting the GI tract, skin, and CNS, producing symptoms of diarrhea, dermatitis, and dementia, respectively. Pellagra may result from a niacin- and protein-deficient diet, isoniazid therapy, or certain diseases that result in poor utilization of tryptophan. Pellagra was the only vitamin-deficiency disease to ever reach epidemic proportions in the US; pellagra is rare today in industrialized countries due to the enrichment of refined flours.

Several synonyms for niacin and niacinamide exist. Synthetic niacin could be produced by the oxidation of nicotine, and the term 'nicotinic acid' evolved. Scientists also coined the terms 'nicotinamide' and 'niacinamide' for the amide form of nicotinic acid. The term 'niacin' has been used generically since the 1940's to label foods and to avoid association of the vitamins with the nicotine alkaloid from tobacco. Thus, the name 'niacin' has been used to denote both chemical forms, which are equivalent as vitamins on a weight basis. Both nicotinic acid and nicotinamide are synthesized for inclusion in nutritional supplements. However, since nicotinic acid and nicotinamide have different pharmacologic properties outside of their use as vitamins, it is important to distinguish between the two forms in pharmaceutical products.

In clinical medicine, nicotinic acid is used as an antilipemic, but nicotinamide (niacinamide) is not effective for this purpose. Nicotinic acid was the first hypolipidemic agent shown to decrease the incidence of secondary myocardial infarction (MI) and reduce total mortality in MI patients. However, no incremental benefit of coadministration of extended-release niacin with lovastatin or simvastatin on cardiovascular morbidity and mortality over and above that demonstrated for extended-release niacin, simvastatin, or lovastatin monotherapy has been established. In addition, the AIM-HIGH trial demonstrated that the concurrent use of extended-release niacin (1500—2000 mg/day PO) and simvastatin does not result in a greater reduction in the incidence of cardiovascular events than simvastatin alone.4 These results are consistent with those of the larger HPS2-THRIVE trial in which the addition of extended-release niacin to effective statin-based therapy did not result in a greater reduction in the incidence of cardiovascular events. Furthermore, there was an increased risk of serious adverse events including an increased incidence of disturbances in diabetes control and diabetes diagnoses, as well as serious gastrointestinal, musculoskeletal, dermatological, infectious, and bleeding adverse events. There was also a statistically insignificant 9% proportional increase in the incidence of death from any cause in the niacin group.5 The ARBITER 6-HALTS trial demonstrated that the addition of extended-release niacin 2000 mg/day to statins results in significant regression in atherosclerosis as measured by carotid intima-media thickness, and is superior to the combination of ezetimibe and a statin.6 In an MRI study, the addition of extended-release niacin 2000 mg/day to statin therapy resulted in a significant reduction in carotid wall area compared to placebo.7 However, the NIA Plaque study, which was presented at the American Heart Association (AHA) 2009 Scientific Sessions, did not find a significant reduction in the progression of atherosclerosis associated with the addition of niacin to statin therapy as compared to statin monotherapy. Additionally, nicotinic acid has been used as a therapy for tinnitus, but efficacy data are scant. Some sustained-release nicotinic acid formulations have a lower incidence of flushing but a higher incidence of hepatotoxicity when compared to immediate-release forms.8 Some dosage forms are available without prescription. The FDA officially approved niacin in 1938.

Zinc Pyrithione

Zinc is a trace element. Zinc is distributed throughout the plant and animal kingdoms, second in abundance only to iron. As a trace element, zinc is essential for biologic functions and, in animals, is important in growth, appetite, testicular maturation, skin integrity, mental activity, wound healing, and immunocompetence. Zinc deficiency, first identified clinically in 1963 in young males in Iran and Egypt, is associated with diets high in unrefined cereal and unleavened bread, total parenteral nutrition (TPN), intestinal disease (i.e., Crohn's disease, pancreatic insufficiency), alcoholism, pregnancy, or in acrodermatitis enteropathica, an autosomal recessive disease characterized by zinc malabsorption. Commercially available zinc salts include zinc acetate, zinc chloride, zinc gluconate, zinc oxide, and zinc sulfate. Zinc sulfate, administered orally or parenterally, is the most common form of zinc used when a nutritional supplement is needed; it is the salt found in zinc-containing multivitamin preparation. Zinc sulfate is also used as an ophthalmic solution for mild ocular irritation. Zinc chloride is sometimes also used for IV nutritional supplementation; oral administration of zinc chloride is associated with significant nausea. Zinc lozenges and zinc nasal spray are purported to treat symptoms of the common cold; however, in June 2009, the FDA issued a MedWatch alert advising patients and health care professionals to discontinue use of Zicam intranasal products due to more than 130 reports of loss of sense of smell (anosmia) which may be permanent or long-lasting. Zinc oxide is a mild astringent with weak antiseptic properties and is applied topically as a sun blocking agent and to treat dermatologic conditions such as abrasions, burns, chafing, diaper rash, and minor skin irritations. Additionally, the antifungal compound zinc undecylenate and the antibacterial agent bacitracin zinc contain zinc as an astringent. Zinc is also used to stabilize insulin preparations such as protamine insulin. Zinc acetate is used topically as a non-prescription agent to treat poison ivy and related Rhus dermatitis. Most recently, oral zinc acetate (Galzin) was granted FDA approval on January 29, 1997 for the oral treatment of Wilson's disease (hepatolenticular degeneration) and is the only prescription-only zinc products.

Mechanism of Action:

Azelaic Acid

The efficacy of azelaic acid in acne vulgaris is due to an antimicrobial effect and an antikeratinizing effect on the follicular epidermis. The antimicrobial effects of azelaic acid involves inhibition of synthesis of microbial cellular proteins; the exact mechanism of action is unknown. Azelaic acid possesses bacteriostatic properties against a variety of aerobic microorganisms, especially Staphylococcus epidermidis and Propionibacterium acnes which are known to be elevated in acne-bearing skin; at high concentrations, azelaic acid is bactericidal against S. epidermidis and P. acnes. By reducing the concentration of bacteria present on the skin, azelaic acid decreases the inflammation associated with acne lesions. Azelaic acid may also possess a direct anti-inflammatory effect by scavenging oxygen radicals. The antikeratinizing effects of azelaic acid may be due to decreased synthesis of filaggrin (keratin filament aggregating protein). By inhibiting filaggrin, azelaic acid may normalize the keratinization of the follicle and produce a reduction in noninflamed acne lesions. Azelaic acid does not affect sebum excretion.

The mechanism of action that results in the efficacy of azelaic acid in acne rosacea is not clear; clinical studies suggest interference with the pathogenic effects in rosacea. Anti-inflammatory effects have been noted in vitro.

The antiproliferative and cytotoxic actions of azelaic acid may be due to reversible inhibition of a variety of oxidoreductive enzymes including DNA polymerase, tyrosinase, and mitochondrial enzymes of the respiratory chain. At the cellular level, azelaic acid causes mitochondrial swelling and accumulation of cytoplasmic lipid droplets. Azelaic acid has shown efficacy in treating such conditions as lentigo maligna, cutaneous malignant melanoma, and melasma (chloasma). When azelaic acid is applied topically in these conditions, there is a reduction in epidermal melanogenesis and replacement of abnormal melanocytes by normal cells; flattening of nodular areas may also occur. Hyperactive and malignant melanocytes are much more susceptible to the effects of azelaic acid than are normal melanocytes.

Niacinamide

Dietary requirements for niacin can be met by the ingestion of either nicotinic acid or nicotinamide; as vitamins, both have identical biochemical functions. As pharmacologic agents, however, they differ markedly. Nicotinic acid is not directly converted into nicotinamide by the body; nicotinamide is only formed as a result of coenzyme metabolism. Nicotinic acid is incorporated into a coenzyme known as nicotinamide adenine dinucleotide (NAD) in erythrocytes and other tissues. A second coenzyme, nicotinamide adenine dinucleotide phosphate (NADP), is synthesized from NAD. These two coenzymes function in at least 200 different redox reactions in cellular metabolic pathways. Nicotinamide is released from NAD by hydrolysis in the liver and intestines and is transported to other tissues; these tissues use nicotinamide to produce more NAD as needed. Together with riboflavin and other micronutrients, the NAD and NADP coenzymes work to convert fats and proteins to glucose and assist in the oxidation of glucose.

In addition to its role as a vitamin, niacin (nicotinic acid) has other dose-related pharmacologic properties. Nicotinic acid, when used for therapeutic purposes, acts on the peripheral circulation, producing dilation of cutaneous blood vessels and increasing blood flow, mainly in the face, neck, and chest. This action produces the characteristic "niacin-flush". Nicotinic acid-induced vasodilation may be related to release of histamine and/or prostacyclin. Histamine secretion can increase gastric motility and acid secretion. Flushing may result in concurrent pruritus, headaches, or pain. The flushing effects of nicotinic acid appear to be related to the 3-carboxyl radical on its pyridine ring. Nicotinamide (niacinamide), in contrast to nicotinic acid, does not contain a carboxyl radical in the 3 position on the pyridine ring and does not appear to produce flushing.

Nicotinic acid may be used as an antilipemic agent, but nicotinamide does not exhibit hypolipidemic activity. Niacin reduces total serum cholesterol, LDL, VLDL, and triglycerides, and increases HDL cholesterol. The mechanism of nicotinic acid's antilipemic effect is unknown but is unrelated to its biochemical role as a vitamin. One of nicotinic acid's primary actions is decreased hepatic synthesis of VLDL. Several mechanisms have been proposed, including inhibition of free fatty acid release from adipose tissue, increased lipoprotein lipase activity, decreased triglyceride synthesis, decreased VLDL-triglyceride transport, and an inhibition of lipolysis. This last mechanism may be due to niacin's inhibitory action on lipolytic hormones. Nicotinic acid possibly reduces LDL secondary to decreased VLDL production or enhanced hepatic clearance of LDL precursors. Nicotinic acid elevates total HDL by an unknown mechanism, but is associated with an increase in serum levels of Apo A-I and lipoprotein A-I, and a decrease in serum levels of Apo-B. Nicotinic acid is effective at elevating HDL even in patients whose only lipid abnormality is a low-HDL value. Niacin does not appear to affect the fecal excretion of fats, sterols, or bile acids. Clinical trial data suggest that women have a greater hypolipidemic response to niacin therapy than men at equivalent doses.

Zinc Pyrithione

Zinc is a component of many metalloenzymes in the human body. Serving as a cofactor, zinc is involved in such functions as synthesis or degradation of major metabolites (i.e., carbohydrates, lipids, proteins, nucleic acids), stabilization of protein and nucleic acid structure, transport processes, immune function, and expression of genetic information. Zinc is abundant in the nucleus of cells where it serves to stabilize RNA and DNA structure and is required for the activity of RNA polymerases important in cell division. Zinc is also present in the crystalline structure of bone, in bone enzymes, and at the zone of demarcation where it is thought to be important for adequate osteoblastic activity, formation of bone enzymes (i.e., alkaline phosphatase), and calcification.

Topically administered zinc acts as an astringent and weak antiseptic. These actions are thought to be mediated by precipitation of proteins by zinc ions. Topical zinc salts include zinc chloride, zinc stearate, zinc oxide, zinc acetate, and zinc sulfate. In addition to its astringent and antiseptic effects, zinc sulfate administered as an ophthalmic solution also aids in the clearance of mucous from the outer surface of the eye and produces mild vasodilatation, however, it does not have any decongestant activity.

Zinc deficiency is manifest in a variety of organ systems signifying the importance of the mineral for biological function and development. Clinical characterization of zinc deficiency includes growth retardation, hypogonadism and hypospermia, delayed sexual maturation, alopecia, impaired wound healing, skin lesions, immune deficiencies, behavioral disturbances, night blindness, and hypogeusia (impaired taste). Some biochemical markers of zinc deficiency include decreased plasma zinc, reduced alkaline phosphatase, low plasma testosterone, decreased retinal alcohol dehydrogenase, and decreased RNA polymerase activity in some tissues. Also, there is impaired T-lymphocyte function and decreased collagen synthesis. Zinc supplementation and adequate nutrition usually results in noticeable clinical improvement in zinc deficient patients.

Non-enzymatic proteins called metallothioneins contain large amounts of zinc. The exact role of zinc in metallothionein function is not known, however, administration of zinc stimulates the production of metallothioneins. Metallothioneins are believed to have a role in cellular antioxidant protection by scavenging free radicals. Metallothioneins bind copper with a much higher affinity than zinc, hence, the use of zinc acetate in treating Wilson's disease and the occurrence of copper deficiency with high dose zinc therapy. In treating Wilson's disease, zinc acetate interferes with copper absorption/reabsorption from the gut by inducing the production of metallothionein in the enterocyte, thereby preventing the serosal transfer of copper into the blood. The protein-bound copper is then excreted in the stool following desquamation of intestinal cells.

Pharmacokinetics

Azelaic Acid

Azelaic acid is applied topically to the skin. Azelaic acid is mainly excreted unchanged in the urine but does undergo some beta-oxidation to shorter chain dicarboxylic acids. Plasma concentrations and daily urinary excretion of azelaic acid are highly dependent on dietary intake.

Following a single application to human skin in vitro, the drug penetrates into the stratum corneum (approximately 3—5% of the applied dose) and other viable skin layers (up to 10% of the dose is found in the epidermis and dermis). Approximately 4% of the topically applied dose is absorbed systemically. Negligible cutaneous metabolism occurs after topical administration. The observed half-lives in healthy subjects are approximately 12 hours after topical dosing, indicating percutaneous absorption rate-limited kinetics. Following topical administration, plasma concentrations and urinary excretion of azelaic acid are not significantly different from baseline levels.

Niacinamide

Nicotinic acid may be administered by the oral or parenteral routes. Nicotinamide is administered orally. Niacin is widely distributed throughout the body and it concentrates in the liver, spleen, and adipose tissue. Niacin undergoes rapid and extensive first-pass metabolism that is dose-rate specific and, at the doses used to treat dyslipidemia, saturable. Niacin is conjugated with glycine to form nicotinuric acid (NUA), which is then excreted in the urine. Some reversible metabolism from NUA back to niacin may occur in small amounts. The other pathway results in the formation of NAD. Nicotinamide is most likely released after the formation of NAD. Nicotinamide does not have hypolipidemic activity, and is further metabolized in the liver to produce N-methylnicotinamide (MNA) and nicotinamide-N-oxide (NNO). MNA is metabolized to two other N-methylated compounds known as 2PY and 4PY, which are excreted in the urine. The formation of 2PY predominates over 4PY in humans. Roughly 12% of nicotinic acid is excreted unchanged in the urine with normal dosages. Greater proportions of niacin are renally excreted unchanged as dosages exceed 1000 mg/day and metabolic pathways become saturated.

Zinc Pyrithione

Zinc supplementation may be administered orally or parenterally. Once in the systemic blood circulation, zinc is primarily bound to albumin and is transported to the liver where some is stored and the rest delivered to extrahepatic tissues. In the plasma, zinc is localized in erythrocytes and leukocytes. Plasma concentrations tend to correspond with dietary intake and physiologic factors (i.e., injury or inflammation) and drop by 50% in the acute phase response to injury probably due to the sequestering of zinc by the liver. Tissue distribution of zinc is highest for the liver, pancreas, kidney, bone, and voluntary muscles. High concentrations also occur in parts of the eye, skin, hair, fingernails, toenails, prostate gland, and spermatozoa. Up to 25% of the daily loss is via biliary and pancreatic secretions.

Contraindications/Precautions

Azelaic Acid

Azelaic acid products that contain propylene glycol should be avoided in patients with a known propylene glycol hypersensitivity; avoid use in patients hypersensitive to any other ingredients of the particular formulation prescribed.1

Azelaic acid has not been well-studied in patients with dark complexions and should be used cautiously in these patients to avoid hypopigmentation.13

An occlusive dressing should not be used with azelaic acid. Avoid ocular exposure and accidental exposure/contact with the mouth and other mucous membranes. If contact with the eye(s) occur, the eye(s) should be washed with large amounts of water; patients should contact their physician if ocular irritation persists.

The safety and effectiveness of azelaic acid cream and gel formulations in neonates, infants, and children under 12 years of age have not been established. The foam formulation is not approved for use in pediatric patients less than 18 years of age.3

Do not apply azelaic acid to areas affected by herpes labialis; exacerbations of herpes infection have been reported.

Worsening or deterioration of asthma has been observed in patients treated with azelaic acid. Instruct drug recipients to contact their physician if signs of an asthma exacerbation (i.e., dyspnea, wheezing) develop during therapy.1

Niacinamide

Patients who have a known hypersensitivity to niacin or any product component should not be given the drug.

While steady state plasma concentrations of niacin are generally higher in women than in men, the absorption, metabolism, and excretion of niacin appears to be similar in both genders. Women have been reported to have greater response to the lipid-lowering effects of nicotinic acid (niacin) when compared to men.

No overall differences in safety and efficacy were observed between geriatric and younger individuals receiving niacin. Other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity for some older individuals cannot be ruled out.

Niacin is contraindicated in patients who have significant or unexplained hepatic disease. Patients who consume large quantities of ethanol (alcoholism), who have risk factors for hepatic disease, or who have a past-history of gallbladder disease, jaundice, or hepatic dysfunction may receive niacin with close clinical observation. Elevations in liver function tests (LFTs) appear to be dose-related. Some sustained-release nicotinic acid (niacin) formulations have a higher incidence of hepatotoxicity when compared to immediate-release dosage forms. Extended-release nicotinic acid preparations (e.g., Niaspan, Slo-Niacin) should not be substituted for equivalent dosages of immediate-release (crystalline) niacin (e.g., Niacor and others). Follow the manufacturer-recommended initial dosage titration schedules for extended-release products, regardless of previous therapy with other niacin formulations. Monitor LFTs in all patients during therapy at roughly 6-month intervals or when clinically indicated. If transaminase levels (i.e., ALT or AST) rise to 3 times the upper limit of normal, or clinical symptoms of hepatic dysfunction are present, niacin should be discontinued.

Nicotinic acid (niacin) can stimulate histamine release, which, in turn, can stimulate gastric acid output. Niacin is contraindicated in patients with active peptic ulcer disease (PUD) because it can exacerbate PUD symptoms. Use niacin with caution in patients with a past history of peptic ulcer disease or in those on maintenance therapy to prevent PUD recurrence.

Due to its vasodilatory action, nicotinic acid (niacin) should be used with caution in those patients with uncorrected hypotension (or predisposition to orthostatic hypotension), acute myocardial infarction, or unstable angina, particularly when vasodilator medications such as nitrates, calcium channel blockers, or adrenergic blocking agents are coadministered (see Drug Interactions). Because the vasodilatory response to niacin may be more dramatic at the initiation of treatment, activities requiring mental alertness (e.g., driving or operating machinery) should not be undertaken until the response to niacin is known.

Niacin, especially in high doses, can cause hyperuricemia. Niacin should be prescribed cautiously to patients with gout (or predisposed to gout). These individuals should be advised not to purchase OTC forms of niacin without the guidance of a physician.

Niacin, especially in high doses, can cause hypophosphatemia. Although the reductions in phosphorus levels are usually transient, clinicians should monitor serum phosphorus periodically in those at risk for this electrolyte imbalance.

Rare cases of rhabdomyolysis have been reported in patients taking lipid-altering dosages of nicotinic acid (niacin) and statin-type agents concurrently (see Drug Interactions). Patients undergoing combined therapy should be carefully monitored for muscle pain, tenderness, or weakness, particularly in the early months of treatment or during periods of upward dose titration of either drug. While periodic CPK and potassium determinations may be considered, there is no evidence that these tests will prevent the occurrence of severe myopathy. If rhabdomyolysis occurs, the offending therapies should be discontinued.

Niacin, especially in high doses, may cause hyperglycemia. Niacin should be prescribed cautiously to patients with diabetes mellitus. These individuals should be advised not to purchase OTC forms of niacin without the guidance of a physician. Niacin has also been reported to cause false-positive results in urine glucose tests that contain cupric sulfate solution (e.g., Benedict's reagent, Clinitest).

Niacin therapy has been used safely in children for the treatment of nutritional niacin deficiency. However, the safety and effectiveness of nicotinic acid for the treatment of dyslipidemias have not been established in neonates, infants and children <= 16 years of age. Nicotinic acid has been used for the treatment of dyslipidemia in pediatric patients under select circumstances. Children may have an increased risk of niacin-induced side effects versus adult populations. At least one pediatric study has concluded that niacin treatment should be reserved for treatment of severe hypercholesterolemia under the close-supervision of a lipid specialist.9 In general, the National Cholesterol Education Program (NCEP) does not recommend drug therapy for the treatment of children with dyslipidemias until the age of 10 years or older.10

Since niacin is an essential nutrient, one would expect it to be safe when administered during pregnancy at doses meeting the recommended daily allowance (RDA). Niacin is categorized as pregnancy category A under these conditions. However, when used in doses greater than the RDA for dyslipidemia, or when used parenterally for the treatment of pellagra, niacin is categorized as pregnancy category C. Most manufacturers recommend against the use of niacin in dosages greater than the RDA during pregnancy. The potential benefits of high-dose niacin therapy should be weighed against risks, since toxicological studies have not been performed.4

According to a manufacturer of niacin (Niaspan), although no studies have been conducted in nursing mothers, excretion into human milk is expected. The manufacturer recommends the discontinuation of nursing or the drug due to serious adverse reactions that may occur in nursing infants from lipid-altering doses of nicotinic acid.4 Niacin, in the form of niacinamide, is excreted in breast milk in proportion to maternal intake. Niacin supplementation is only needed in those lactating women who do not have adequate dietary intake. The Recommended Daily Allowance (RDA) of the National Academy of Science for niacin during lactation is 20 mg.11 There are no safety data regarding the use of nicotinic acid in doses above the RDA during breast-feeding. Consider the benefits of breast-feeding, the risk of potential infant drug exposure, and the risk of an untreated or inadequately treated condition. If a breast-feeding infant experiences an adverse effect related to a maternally ingested drug, healthcare providers are encouraged to report the adverse effect to the FDA.

Use niacin with caution in patients with renal disease (renal failure or severe renal impairment) since niacin metabolites are excreted through the kidneys. It appears that no special precautions are needed when administering niacin to meet the recommended nutritional daily allowance (RDA). Use caution when administering higher dosages.

Nicotinic acid (niacin) occasionally causes slight decreases in platelet counts or increased prothrombin times and should be used with caution in patients with thrombocytopenia, coagulopathy, or who are receiving anticoagulant therapy. Patients who will be undergoing surgery should have blood counts monitored. Nicotinic acid (niacin) is contraindicated in patients with arterial bleeding.

The federal Omnibus Budget Reconciliation Act (OBRA) regulates medication use in residents (e.g., geriatric adults) of long-term care facilities (LTCFs). According to OBRA, glucose and liver function tests should be evaluated regularly because niacin interferes with glucose control, can aggravate diabetes, and can exacerbate active gallbladder disease and gout. Flushing is a common side effect of niacin.12

Zinc Pyrithione

Parenteral zinc salts are classified as pregnancy category C. No adequate and well-controlled trials in pregnant women have been performed with parenteral zinc. Exercise caution when using parenteral zinc supplementation during pregnancy. Adverse effects have not been reported with the normal daily intake of zinc within the recommended dietary daily intakes for a pregnant female.13 Galzin (oral zinc acetate) studies conducted in the US for Wilson's disease included 19 symptomatic and presymptomatic women who became pregnant and continued treatment; these women delivered 26 live birth babies. At the time of delivery, the duration of zinc acetate therapy had ranged from 0.7 to 13.7 years and all patients were using zinc acetate within the normally recommended dosage ranges. Measurement of urinary copper excretion indicated adequate control of copper levels in most patients before and during pregnancy. The results also indicated that during pregnancy, the mothers' health was protected by zinc acetate therapy, and no adverse effects on liver or neurological functions were reported. Limited pregnancy outcome data indicates an incidence of miscarriages consistent with those in the general population. In a separate double-blind study, 580 African-American pregnant women with low plasma zinc levels were randomized to receive daily doses of either zinc 25 mg or placebo until delivery. Higher infant birth weights and larger infant head circumferences were observed in newborns of women receiving zinc supplementation and with a body mass index (BMI) of less than 26 kg/m2.14

Zinc supplementation can interfere with the absorption of copper. Administration of zinc to patients with hypocupremia (copper deficiency) can further decrease serum copper levels.

Pregnancy

Azelaic Acid

Azelaic acid is classified FDA pregnancy risk category B. Animal data suggests embryotoxic effects when administered orally; no teratogenic effects were observed. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, azelaic acid should be used during pregnancy only if clearly needed.115

Niacinamide

Since niacin is an essential nutrient, one would expect it to be safe when administered during pregnancy at doses meeting the recommended daily allowance (RDA). Niacin is categorized as pregnancy category A under these conditions. However, when used in doses greater than the RDA for dyslipidemia, or when used parenterally for the treatment of pellagra, niacin is categorized as pregnancy category C. Most manufacturers recommend against the use of niacin in dosages greater than the RDA during pregnancy. The potential benefits of high-dose niacin therapy should be weighed against risks, since toxicological studies have not been performed.4

Zinc Pyrithione

Parenteral zinc salts are classified as pregnancy category C. No adequate and well-controlled trials in pregnant women have been performed with parenteral zinc. Exercise caution when using parenteral zinc supplementation during pregnancy. Adverse effects have not been reported with the normal daily intake of zinc within the recommended dietary daily intakes for a pregnant female.13 Galzin (oral zinc acetate) studies conducted in the US for Wilson's disease included 19 symptomatic and presymptomatic women who became pregnant and continued treatment; these women delivered 26 live birth babies. At the time of delivery, the duration of zinc acetate therapy had ranged from 0.7 to 13.7 years and all patients were using zinc acetate within the normally recommended dosage ranges. Measurement of urinary copper excretion indicated adequate control of copper levels in most patients before and during pregnancy. The results also indicated that during pregnancy, the mothers' health was protected by zinc acetate therapy, and no adverse effects on liver or neurological functions were reported. Limited pregnancy outcome data indicates an incidence of miscarriages consistent with those in the general population. In a separate double-blind study, 580 African-American pregnant women with low plasma zinc levels were randomized to receive daily doses of either zinc 25 mg or placebo until delivery. Higher infant birth weights and larger infant head circumferences were observed in newborns of women receiving zinc supplementation and with a body mass index (BMI) of less than 26 kg/m2.14

Breast-feeding

Azelaic Acid

According to the manufacturer, caution should be exercised when azelaic acid is administered to breast-feeding women. In vitro studies assessing human milk partitioning suggests that azelaic acid may be distributed into breast milk. However, since less than 4% of a topically applied dose is systemically absorbed, the uptake of azelaic acid into maternal milk is not expected to cause a significant change from baseline azelaic acid concentrations in the milk.115 Consider the benefits of breast-feeding, the risk of potential infant drug exposure, and the risk of an untreated or inadequately treated condition. If a breast-feeding infant experiences an adverse effect related to a maternally ingested drug, healthcare providers are encouraged to report the adverse effect to the FDA.

Niacinamide

According to a manufacturer of niacin (Niaspan), although no studies have been conducted in nursing mothers, excretion into human milk is expected. The manufacturer recommends the discontinuation of nursing or the drug due to serious adverse reactions that may occur in nursing infants from lipid-altering doses of nicotinic acid.4 Niacin, in the form of niacinamide, is excreted in breast milk in proportion to maternal intake. Niacin supplementation is only needed in those lactating women who do not have adequate dietary intake. The Recommended Daily Allowance (RDA) of the National Academy of Science for niacin during lactation is 20 mg.11 There are no safety data regarding the use of nicotinic acid in doses above the RDA during breast-feeding. Consider the benefits of breast-feeding, the risk of potential infant drug exposure, and the risk of an untreated or inadequately treated condition. If a breast-feeding infant experiences an adverse effect related to a maternally ingested drug, healthcare providers are encouraged to report the adverse effect to the FDA.

Zinc Pyrithione

Maternal zinc supplementation during lactation appears to have no significant effect on zinc concentrations normally found in human milk. Use of zinc salts within the recommended daily dietary intake for lactating women is generally recognized as safe.1613 Consider the benefits of breast-feeding, the risk of potential infant drug exposure, and the risk of an untreated or inadequately treated condition. If a breast-feeding infant experiences an adverse effect related to a maternally administered drug, healthcare providers are encouraged to report the adverse effect to the FDA.

Adverse Reactions/Side Effects

Azelaic Acid

Most side effects occurring with the use of azelaic acid are dermatologic in nature and mild in severity. These effects include burning sensation or stinging (1—6.2%), paresthesias or tingling (1—6.2%), pruritus (1—5%), xerosis (dry skin, < 5%), erythema (< 2%), skin irritation (< 2%), contact dermatitis (< 1%), rash (unspecified) (< 1%), peeling (< 1%), dermatitis (< 1%), and edema (< 1%). In patients with dark complexions, skin hypopigmentation may occur. The following additional adverse reactions have been reported rarely: vitiligo depigmentation, small depigmented spots, hypertrichosis, reddening (signs of keratosis pilaris), and exacerbation of recurrent herpes viral infection (i.e., herpes labialis).213

Post-marketing use of azelaic acid has been associated with the development of hypersensitivity reactions (including angioedema, ocular inflammation, facial swelling, and urticaria) and asthma exacerbation (i.e., dyspnea, wheezing). In addition, cases of iridocyclitis, or inflammation of the iris, have been noted following accidental exposure of the eye to the topical gel. Due to the voluntary nature of post-marketing reports, neither a frequency nor a definitive causal relationship can be established.1

Niacinamide

Niacin (nicotinic acid), when administered in doses equivalent to the RDA, is generally nontoxic. Niacinamide also rarely causes adverse reactions. Larger doses of nicotinic acid (i.e., >= 1 g/day PO), can cause adverse reactions more frequently. Differences in adverse reaction profiles can be explained by the fact that nicotinic acid has pharmacologic properties that are different from niacinamide.

Peripheral vasodilation is a well-known adverse reaction to niacin. It is characterized by flushing; warmth; and burning or tingling of the skin, especially in the face, neck, and chest. Hypotension can be caused by this vasodilation. Patients should avoid sudden changes in posture to prevent symptomatic or orthostatic hypotension. Dizziness and/or headache, including migraine, can occur. Cutaneous flushing is more likely to occur with immediate-release preparations as opposed to sustained-release ones and also increases in incidence with higher doses.8 Following 4-weeks of maintenance therapy of 1500 mg daily, patients receiving immediate release niacin averaged 8.6 flushing events compared to 1.9 events in the Niaspan group. In placebo-controlled studies of Niaspan, flushing occurred in 55—69% of patients compared to 19% of patients receiving placebo. Flushing was described as the reason for discontinuing therapy for 6% of patients receiving Niaspan in pivotal studies.4 These reactions usually improve after the initial 2 weeks of therapy. Some patients develop generalized pruritus as a result of peripheral flushing. In placebo controlled trials, pruritus was reported in 0—8% of patients receiving Niaspan compared to 2% of patients taking placebo. Rash (unspecified) was reported in 0—5% of patients in the Niaspan group compared to no patients in the placebo group.4 Patients should avoid ethanol or hot drinks that can precipitate flushing. Flushing can be minimized by taking niacin with meals, using low initial doses, and increasing doses gradually. If necessary, taking one aspirin (e.g., 325 mg) 30 minutes before each dose can help prevent or reduce flushing. Spontaneous reports with niacin suggest that flushing may also be accompanied by symptoms of dizziness or syncope, sinus tachycardia, palpitations, atrial fibrillation, dyspnea, diaphoresis, chills, edema, or exacerbations of angina. On rare occasions, cardiac arrhythmias or syncope has occurred. Hypersensitivity or anaphylactoid reactions have been reported rarely during niacin therapy; episodes have included one or more of the following features: anaphylaxis, angioedema, urticaria, flushing, dyspnea, tongue edema, laryngeal edema, face edema, peripheral edema, laryngospasm, maculopapular rash, and vesiculobullous rash (vesicular rash, bullous rash).

Niacin can produce a variety of GI effects, such as nausea/vomiting, abdominal pain, diarrhea, bloating, dyspepsia, or flatulence, when taken in large doses. Eructation and peptic ulcer has been reported with post-marketing experience of Niaspan. Compared to placebo, diarrhea was reported in 7—14% (vs. 13%), nausea in 4—11% (vs. 7%), and vomiting in 0—9% (vs. 4%) of patients receiving Niaspan.4 These effects are attributed to increased GI motility and may disappear after the first 2 weeks of therapy. Administering niacin with meals can reduce these adverse reactions.

Jaundice can result from chronic liver damage caused by niacin. It has been shown that elevated hepatic enzymes occur more frequently with some sustained-release niacin than with immediate-release products.8 However, in a study of 245 patients receiving Niaspan (doses ranging from 500—3000 mg/day for a mean of 17 weeks) no patients with normal serum transaminases at baseline experienced elevations to > 3x the upper limit of normal. Sustained-release products have been associated with post-marketing reports of hepatitis and jaundice, including Niaspan. Regular liver-function tests should be performed periodically. The changes in liver function induced by niacin are typically reversible with drug discontinuation. However, rare cases of fulminant hepatic necrosis and hepatic failure have been reported. Some cases have occurred after the substitution of sustained-release dosage forms for immediate-release products at directly equivalent doses; these dosage forms are not bioequivalent. Dosage titration schedules must be observed for any patient switched to a sustained-release niacin product, even if the patient was previously taking immediate-release therapy.4

Niacin interferes with glucose metabolism and can result in hyperglycemia.4 This effect is dose-related. During clinical anti-lipemic trials, increases in fasting blood glucose above normal occurred frequently (e.g., 50%) during niacin therapy. Some patients have required drug discontinuation due to hyperglycemia or exacerbation of diabetes. In the AIM-HIGH trial of patients with stable cardiovascular disease, the incidence of hyperglycemia (6.4% vs. 4.5%) and diabetes mellitus (3.6% vs. 2.2%) was higher in niacin plus simvastatin-treated patients compared to the simvastatin plus placebo group. Close blood glucose monitoring is advised for diabetic or potentially diabetic patients during treatment with niacin; adjustment of diet and/or antidiabetic therapy may be necessary.4

Niacin, especially in high doses, can cause hyperuricemia. Gout has been reported in post-marketing surveillance of Niaspan.4 Therefore, patients predisposed to gout should be treated with caution.

Niacin, especially in high doses (>= 2 g/day PO), can cause hypophosphatemia (mean decrease 13%). Serum phosphorus concentrations should be monitored periodically in patients at risk for hypophosphatemia.4

Nicotinic acid (niacin) occasionally causes slight decreases in platelet counts (mean reduction 11%) or increased prothrombin times (mean increase 4%), especially in high doses (>= 2 g/day PO). Rarely do these reactions result in coagulopathy or thrombocytopenia, but clinically significant effects might occur in patients with other risk factors or who are predisposed to these conditions.4

Asthenia, nervousness, insomnia, and paresthesia have been reported during niacin therapy. Rare cases of rhabdomyolysis have been reported in patients taking niacin (nicotinic acid) in doses >=1 g/day PO and HMG-CoA reductase inhibitors (i.e., 'statins') concurrently. In the AIM-HIGH trial, 4 cases (0.2%) of rhabdomyolysis were reported in the niacin; simvastatin group compared with 1 case in the simvastatin plus placebo group. Rhabdomyolysis may present as myopathy (myalgia, myasthenia, muscle cramps, muscle weakness, muscle tenderness, fatigue), elevations in creatinine phosphokinase (CPK), or renal dysfunction (renal tubular obstruction). Toxicity to the skeletal muscle occurs infrequently but can be a serious adverse reaction. This toxicity appears to be reversible after discontinuation of therapy.4

Niacin also has been associated with a variety of ophthalmic adverse effects including blurred vision and macular edema.4

Although uncommon, niacin may be associated with skin hyperpigmentation or acanthosis nigricans. Dry skin (xerosis) also has been reported during post-marketing surveillance of Niaspan.417

During clinical trials, increased cough was reported in <2—8% (vs. 6%) of patients receiving Niaspan compared to placebo.4

Zinc Pyrithione

The most common adverse reactions to oral administration of zinc salts are nausea, vomiting, dyspepsia, and abdominal pain. These adverse events usually occur during high dose therapy. Adverse reactions reported with zinc acetate administration include gastric irritation and elevated pancreatic enzymes. Abdominal discomfort may be abated by administration with food.1819

Excessive zinc intake can lead to development of sideroblastic anemia which is characterized by anemia, leukopenia, and neutropenia. Sideroblastic anemia develops as a result of zinc-induced hypocupremia (copper deficiency). These effects are totally reversible following discontinuation of excessive zinc intake.20

Storage

Store this medication in its original container at 68°F to 77°F (20°C to 25°C) and away from heat, moisture and light. Keep all medicine out of the reach of children. Throw away any unused medicine after the beyond use date. Do not flush unused medications or pour down a sink or drain.

  • 1. a. b. c. d. e. f. g. h. Finacea (azelaic acid) topical gel package insert. Whippany, NJ: Bayer Healthcare; 2016 Aug.
  • 2. a. b. Azelex (azelaic acid cream) 20% [package insert]. Irvine, CA: Allergan; 2013.
  • 3. a. b. c. d. Finacea (azelaic acid) 15% topical foam package insert. Whippany, NJ: Bayer HealthCare Pharmaceuticals Inc.; 2015 Jul.
  • 4. a. b. c. d. e. f. g. h. i. j. k. l. m. n. o. p. q. r. Niaspan (niacin extended-release) tablet package insert. North Chicago, IL: Abbott Laboratories; 2015 Apr.
  • 5. HPS2-THRIVE Collaborative Group. Effects of extended-release niacin with laropiprant in high-risk patients. N Engl J Med 2014;371:203-12.
  • 6. Taylor AJ, Villines TC, Stanck EJ, et al. Extended-release niacin or ezetimibe and carotid intima-media thickness. N Engl J Med 2009. Epub ahead of print, doi:10.1056/NEJMoa907569.
  • 7. Lee JMS, Robson MD, Yu LM, et al. Effects of high-dose modified-release nicotinic acid on atherosclerosis and vascular function: A randomized, placebo-controlled, magnetic resonance imaging study. J Am Coll Cardiol 2009;54:1787—94.
  • 8. a. b. c. McKenney JM, et al. A comparison of the efficacy and toxic effects of sustained- vs immediate-release niacin in hypercholesterolemic patients. JAMA 1994;271:672-7.
  • 9. Colletti RB, Neufeld EJ, Roff NK, et al. Niacin treatment of hypercholesterolemia in children. Pediatrics 1993;92:78-82.
  • 10. Expert Panel: National Cholesterol Education Program. Report of the expert panel on blood cholesterol levels in children and adolescents. Pediatrics 1992;89(suppl 2):525-84.
  • 11. a. b. Niacinamide. In: Drugs in Pregnancy and Lactation. A Reference Guide to Fetal and Neonatal Risk. Briggs GG, Freeman RK, Yaffe SJ, (eds.) 7th ed., Philadelphia PA: Lippincott Williams and Wilkins; 2005:1140-1
  • 12. Health Care Financing Administration. Interpretive Guidelines for Long-term Care Facilities. Title 42 CFR 483.25(l) F329: Unnecessary Drugs. Revised 2015.
  • 13. a. b. c. Standing Committee on the Scientific Evaluation of Dietary Reference Intakes, Panel on Micronutrients and the Subcommittee on Upper Reference Levels of Nutrients, Food and Nutrition Board, et al. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium and Zinc. The National Academy of Sciences Press, Washington DC;2001:177-204.
  • 14. a. b. Goldenberg RL, Tamura T, Neffers Y, et al. The effect of zinc supplementation on pregnancy outcome. JAMA 1995;274:463-8.
  • 15. a. b. Azelex (azelaic acid) package insert. Irvine, CA: Allergan, Inc.; 2004 May.
  • 16. Lawrence RA. Chapter 9: Diet and dietary supplements for the mother and infant. In: Breastfeeding- A Guide for the Medical Profession. 5th ed. St. Louis MO: Mosby, Inc.; 1999.
  • 17. Niacor (Niacin tablets) package insert. Minneapolis, MN: Upsher-Smith Laboratories, Inc.; 2000 Feb.
  • 18. Jafek BW, Linschoten MR, Murrow BW: Anosmia after intranasal zinc gluconate use. Am J Rhinol 2004;18:137-141.
  • 19. Zinc chloride injection package insert. Lake Forest, IL: Hospira, Inc.; 2017 Sept.
  • 20. Zinc sulfate solution for injection package insert. Shirley, NY: Regent, Inc.; 2019 July.

Related Medications