Riboflavin Injection

Overview of Riboflavin (Vitamin B2) Injection

Dosage Strength of Riboflavin Injection

10 mg/mL 30 mL Vial

General Information

Riboflavin, or vitamin B2, is a water-soluble vitamin found in such foods as milk, meat (especially liver and kidney), eggs, nuts, enriched flour, and green vegetables. Whole grains and cereals are not good sources. It is used to treat and prevent vitamin B2 deficiency, although a true riboflavin-deficiency disease state has not been described in humans. Since several of the water-soluble B-vitamins are involved in numerous metabolic pathways, a disease state often indicates deficiencies of multiple vitamins. In pellagra, there is a deficiency of both niacin and riboflavin. Riboflavin has been used to treat microcytic anemia associated with splenomegaly and glutathione reductase deficiency. Use of riboflavin was approved by the FDA in 1940. In 1998, mega-doses of riboflavin were shown to effectively reduce the incidence of migraine headache.1

Mechanism of Action

Flavoproteins (i.e., combinations of riboflavin with proteins) are enzymes that participate in tissue respiration as components of the electron transport system. Riboflavin is converted in vivo to riboflavin 5-phosphate (flavin mononucleotide or FMN), which, in turn, is converted to flavin adenine dinucleotide (FAD). Riboflavin acts indirectly in the maintenance of erythrocyte integrity. Conversion of tryptophan to niacin and activation of pyridoxine requires riboflavin. Since mitochondrial dysfunction may play a role in the pathogenesis of migraine, the effects riboflavin on mitochondrial metabolism may explain its ability to reduce the incidence of migraine headache.1

Pharmacokinetics

Riboflavin is usually administered orally, but it may be given parenterally as a component of a multivitamin injection. Riboflavin 5-phosphate is rapidly dephosphorylated in the GI lumen to FMN before absorption occurs. FAD and FMN are widely distributed to body tissues. Riboflavin is primarily stored as FAD in the heart, liver, spleen, and kidneys. Riboflavin crosses the placenta and is distributed into breast milk. The half-life is 66—84 minutes. Phosphorylation to FMN occurs in the liver, GI mucosal cells, and erythrocytes, with subsequent conversion to FAD in the liver. Approximately 9% of the parent compound is excreted unchanged in the urine. The urinary rate of riboflavin excretion increases with increasing doses.

Route-Specific Pharmacokinetics

Oral Route Riboflavin readily absorbed from the upper GI tract. Food increases the extent of absorption, while conditions such as hepatitis, cirrhosis, and biliary obstruction, or concomitant use of probenecid decrease absorption.

Contraindications/Precautions

No absolute contraindications to riboflavin (vitamin B2) use are known.

Appropriate maternal riboflavin (vitamin B2) intake is encouraged during pregnancy (FDA pregnancy risk category A). The pregnancy risk factor increases to FDA risk category C if the vitamin is used in dosages exceeding the recommended RDA during pregnancy. Adverse effects have not been reported with the normal daily intake of riboflavin within the recommended dietary daily intakes for a pregnant female.2 The use of riboflavin in excess of the recommended dietary allowance during normal pregnancy should be avoided unless, in the judgment of the physician, potential benefits in a specific, unique case outweigh the significant hazards involved.

Appropriate maternal intake of riboflavin (vitamin B2) is important during lactation. The American Academy of Pediatrics has considered the use of riboflavin compatible with breast-feeding.3 Use of riboflavin within the recommended daily dietary intake for lactating women is generally recognized as safe.2 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.

Pregnancy

Appropriate maternal riboflavin (vitamin B2) intake is encouraged during pregnancy (FDA pregnancy risk category A). The pregnancy risk factor increases to FDA risk category C if the vitamin is used in dosages exceeding the recommended RDA during pregnancy. Adverse effects have not been reported with the normal daily intake of riboflavin within the recommended dietary daily intakes for a pregnant female.2 The use of riboflavin in excess of the recommended dietary allowance during normal pregnancy should be avoided unless, in the judgment of the physician, potential benefits in a specific, unique case outweigh the significant hazards involved.

Breast-Feeding

Appropriate maternal intake of riboflavin (vitamin B2) is important during lactation. The American Academy of Pediatrics has considered the use of riboflavin compatible with breast-feeding.3 Use of riboflavin within the recommended daily dietary intake for lactating women is generally recognized as safe.2 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.

Interactions

There are no drug interactions associated with Riboflavin, Vitamin B2 products.

Adverse Reactions/Side Effects

Riboflavin in normal dietary dosages produces no adverse reactions. Large doses have caused bright yellow urine discoloration, which has resulted in interference with urinalysis results. Riboflavin can produce fluorescent substances in the urine and plasma, which could result in false elevations in fluorometric determinations of catecholamines and urobilinogen.4

Storage

Store this medication in a refrigerator at 36°F to 46°F (2°C to 8°C). Keep all medicines 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. Schoenen J, Jacquy J, Lenaerts M. Effectiveness of high-dose riboflavin in migraine prophylaxis. Neurology 1998;50:466-470.
• 2. a. b. c. d. Standing Committee on the Scientific Evaluation of Dietary Reference Intakes - Panel on Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Panthothenic Acid, Biotin, and Choline and the Subcommittee on Upp
• 3. a. b. American Academy of Pediatrics (AAP) Committee on Drugs. Transfer of drugs and other chemicals into human milk. Pediatrics 2001;108(3):776-789.
• 4. Riboflavin (vitamin B2). McKevoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.