Riboflavin 5 Phosphate Sodium (VIT B2) Injection

Generic name: Riboflavin-5-Phosphate Sodium
Synonyms: Flavin mononucleotide (FMN), Riboflavin sodium phosphate
Drug class: Water-soluble vitamin; precursor to flavoprotein coenzymes
Formulation: Sterile injectable solution for IV use
Typical concentration: 1–10 mg/mL depending on manufacturer
Appearance: Clear yellow to orange solution; strongly fluorescent

Clinical uses include:

• Nutritional supplementation in deficiency states (malabsorption, alcoholism, prolonged TPN)
• Supportive therapy in mitochondrial disorders
• Adjunctive therapy in migraines (IV preparation sometimes used in infusion therapy programs)
• Part of multivitamin IV infusion formulas ("IV drips")
• Situations requiring rapid replacement of riboflavin stores

Pharmacology summary:
Riboflavin-5-phosphate is the phosphorylated, active form of riboflavin and a direct precursor to FMN and FAD, essential coenzymes in oxidative metabolism, energy production, and antioxidant pathways.

(Doses may vary based on institutional protocols; adjust according to patient condition.)

General supplementation:

• 5–50 mg IV as part of an IV multivitamin or infusion mixture.
• Administer diluted in compatible IV fluids (e.g., NS or D5W).
• Infuse over 30–60 minutes to minimize irritation.

Riboflavin deficiency:

• 10–25 mg IV daily until clinical improvement, then switch to oral therapy.

Mitochondrial / metabolic support (off-label):

• 25–100 mg IV, frequency varies per specialist recommendation.

Migraine therapy (off-label):

• 50–100 mg IV as part of an infusion protocol (often combined with magnesium and other vitamins).

Note: Riboflavin is generally very safe, but IV administration should be performed under clinical supervision.

Riboflavin-5-phosphate (FMN) is a biologically active form of vitamin B2 and precursor to flavin adenine dinucleotide (FAD).
Both FMN and FAD act as essential coenzymes in:

A. Cellular Energy Production

• FMN and FAD participate in oxidation-reduction (redox) reactions in:
  • Electron transport chain (Complex I & II)
  • Krebs cycle
  • β-oxidation of fatty acids
• Supports ATP generation and mitochondrial function.

B. Antioxidant Activity

• Coenzyme for glutathione reductase, essential for maintaining reduced glutathione (GSH).
• Supports detoxification and oxidative stress management.

C. Amino Acid & Drug Metabolism

• Cofactor in metabolism of:
  • Tryptophan
  • Pyridoxine (Vitamin B6 activation)
  • Niacin synthesis
  • Various xenobiotics (cytochrome P450 function)

D. Maintenance of Healthy Skin, Eyes, and Mucous Membranes

• Supports epithelial cell turnover
• Promotes normal vision and prevents corneal vascularization

E. Hematologic Function

• Important for normal erythropoiesis

Deficiency can contribute to anemia

Absolute Contraindications:

• Known hypersensitivity to riboflavin or any component of the formulation.

Relative Precautions:

• Renal impairment: Riboflavin is renally excreted; accumulation is not dangerous but may cause more intense yellow urine.
• History of photosensitivity disorders: Riboflavin can increase photosensitivity; advise avoidance of excessive UV exposure.
• Gallbladder disease: High doses rarely increase bilirubin mildly; caution in severe liver dysfunction.
• IV site irritation: Highly colored solution may cause local irritation or staining of tissues in case of extravasation.

Special Monitoring:

• Infusion site for irritation
• Allergic reactions (rare)
• Avoid exposure of solution to strong light (vitamin is light-sensitive)

Drug Interactions:

• Anticholinergic drugs: May delay gastric emptying, but relevant only to oral administration.
• Probenecid: Can reduce riboflavin renal clearance.
• Photosensitizing drugs (e.g., tetracyclines, thiazides): Riboflavin may enhance photosensitivity.
• Chlorpromazine, TCAs, some anticonvulsants: Chronic use may reduce riboflavin levels.

Lab Interactions:

• High-dose riboflavin can cause false elevation or interference in:
  • Urine colorimetric tests
  • Some fluorometric assays (due to natural fluorescence)

Food interactions: Not applicable to IV administration.

Riboflavin is generally very safe; adverse effects are usually mild.

Common:

• Bright yellow urine (harmless)
• Mild warmth or flushing during infusion
• Mild local irritation at IV site

Less Common:

• Headache
• Dizziness
• Nausea (usually if given too rapidly)
• Hypersensitivity reactions (rare)

Rare but serious:

• Anaphylactoid reaction (extremely rare)
• Extravasation can cause local tissue staining and irritation

Pregnancy:

• Riboflavin is Category A equivalent (safe in pregnancy).
• Required for fetal development; deficiency can cause maternal anemia and fetal growth impairment.
• IV supplementation acceptable if clinically indicated.

Breastfeeding:

• Riboflavin is excreted in breast milk, but safe and considered beneficial.
• No known adverse effects in infants at therapeutic doses.

• Store at 20–25°C (68–77°F) unless otherwise specified by manufacturer.
• Protect from light—riboflavin is highly photosensitive.
• Do not freeze.
• Use within recommended time after opening vial; discard unused portion according to sterile handling guidelines.

(Standard medical/pharmaceutical references – no external links)

1. Micromedex Drug Reference – Riboflavin and Riboflavin-5-Phosphate
2. Lexicomp Online – Riboflavin Monograph
3. British National Formulary (BNF) – Vitamin B2
4. NIH Office of Dietary Supplements – Riboflavin Fact Sheet
5. Remington: The Science and Practice of Pharmacy
6. Goodman & Gilman’s: The Pharmacological Basis of Therapeutics