Usage
Biotin is prescribed for the treatment and prevention of biotin deficiency. This deficiency can be caused by a variety of factors including inadequate dietary intake, genetic disorders affecting biotin metabolism (biotinidase deficiency, holocarboxylase synthetase deficiency), prolonged antibiotic use, anticonvulsant therapy, or excessive consumption of raw egg whites. It’s also used in patients undergoing kidney dialysis and in those who smoke, as these groups may have lower biotin levels. Biotin plays a vital role as a cofactor for several carboxylase enzymes involved in critical metabolic processes, including gluconeogenesis, fatty acid synthesis, and amino acid catabolism.
While commonly promoted for hair loss, brittle nails, and other conditions, robust scientific evidence supporting these uses is limited.
Pharmacological Classification: Vitamin, coenzyme, water-soluble B-vitamin (vitamin B7 or vitamin H).
Mechanism of Action: Biotin functions as a coenzyme for carboxylases, enzymes that catalyze the addition of a carboxyl group to a substrate. These carboxylation reactions are essential for various metabolic pathways including fatty acid synthesis, gluconeogenesis, and amino acid catabolism.
Alternate Names
Vitamin B7, Vitamin H, Coenzyme R
How It Works
Pharmacodynamics: Biotin’s primary role is as a cofactor for five carboxylases: acetyl-CoA carboxylase 1 and 2, pyruvate carboxylase, propionyl-CoA carboxylase, and methylcrotonyl-CoA carboxylase. These enzymes are crucial in various metabolic processes. Acetyl-CoA carboxylases are involved in fatty acid synthesis. Pyruvate carboxylase is involved in gluconeogenesis, while propionyl-CoA carboxylase and methylcrotonyl-CoA carboxylase are involved in the metabolism of certain amino acids and fatty acids.
Pharmacokinetics:
- Absorption: Biotin is readily absorbed from the gastrointestinal tract, with nearly 100% absorption of free biotin, even at pharmacological doses up to 20 mg/day. It’s found naturally in food bound to protein, requiring biotinidase for release and absorption.
- Metabolism: Biotin is not extensively metabolized.
- Elimination: Biotin is excreted primarily in the urine, both as unchanged biotin and biocytin (biotin bound to lysine). Small amounts are also eliminated in the feces.
Dosage
Standard Dosage
Adults:
The adequate intake (AI) for adults is 30 mcg/day. For biotin deficiency, doses of 5-10 mg/day are typically used. Some experts recommend increasing the dose to 15-20 mg/day at the onset of puberty.
Children:
Recommendations for adequate intakes (AIs) for biotin in children are as follows:
- Birth to 6 months: 5 mcg/day
- 7-12 months: 6 mcg/day
- 1-3 years: 8 mcg/day
- 4-8 years: 12 mcg/day
- 9-13 years: 20 mcg/day
- 14-18 years: 25 mcg/day
For children with biotinidase deficiency, doses of 5-10 mg/day, or even up to 20 mg/day after puberty, may be necessary. For partial deficiency, 1–5 mg/day is often used.
Special Cases:
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Elderly Patients: Dosage adjustments are not typically necessary unless there is underlying renal impairment.
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Patients with Renal Impairment: Clearance of biotin may be reduced in patients with renal impairment. Monitoring is recommended, and dose adjustments may be necessary.
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Patients with Hepatic Dysfunction: Dose adjustment is not generally required as biotin is primarily excreted renally.
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Patients with Comorbid Conditions: No specific dose adjustments based solely on comorbid conditions like diabetes or cardiovascular disease are indicated, but consider patient-specific factors.
Clinical Use Cases
Biotin has no specific dosage recommendations for clinical settings such as intubation, surgical procedures, mechanical ventilation, ICU use, or emergency situations. Its use is primarily for biotin deficiency.
Dosage Adjustments
Dose modification might be necessary based on individual patient factors, such as renal function, and monitoring of biotin levels is recommended, particularly in patients receiving high doses.
Side Effects
Common Side Effects
Biotin is generally well-tolerated, and side effects are rare. No adverse effects have been consistently reported at doses up to 200mg orally or 20mg intravenously.
Rare but Serious Side Effects
No serious side effects have been consistently associated with biotin use.
Long-Term Effects
No long-term adverse effects have been consistently documented with biotin supplementation.
Adverse Drug Reactions (ADR)
No clinically significant ADRs requiring immediate intervention have been consistently associated with biotin.
Contraindications
Known hypersensitivity to biotin represents a contraindication.
Drug Interactions
Biotin may interfere with certain laboratory tests, particularly immunoassays that utilize biotin-streptavidin binding. High doses of biotin can lead to falsely high or low results for various tests, including thyroid function tests and troponin levels. Patients should discontinue biotin supplementation for at least 72 hours before such tests, particularly if on high-dose therapy (≥100 mg/day). Patients with renal impairment may require longer periods of abstinence due to potential prolonged elimination rates. No other clinically significant drug interactions are known.
Pregnancy and Breastfeeding
Biotin is considered likely safe during pregnancy and breastfeeding when taken in recommended amounts (30 mcg/day during pregnancy and 35 mcg/day during breastfeeding). However, excessive biotin intake during pregnancy could potentially pose risks.
Drug Profile Summary
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Mechanism of Action: Cofactor for carboxylases involved in crucial metabolic pathways.
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Side Effects: Generally well-tolerated with rare side effects.
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Contraindications: Hypersensitivity to biotin.
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Drug Interactions: Interference with laboratory tests, especially immunoassays.
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Pregnancy & Breastfeeding: Likely safe in recommended amounts.
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Dosage: AI for adults is 30 mcg/day. For deficiency, 5-10 mg/day. Pediatric doses vary by age.
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Monitoring Parameters: Monitor biotin levels in patients receiving high doses, especially those with renal impairment. Consider laboratory test interference and adjust timing as needed.
Popular Combinations
Biotin is often included in B-complex vitamin supplements and multivitamins.
Precautions
- General Precautions: Assess for potential biotin deficiency through clinical presentation and dietary evaluation. Inquire about biotin supplement use before ordering laboratory tests.
- Specific Populations: Advise pregnant and breastfeeding women to stick to recommended intakes. Exercise caution in patients with renal impairment.
- Lifestyle Considerations: No specific lifestyle considerations apart from ensuring a balanced diet.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Biotin?
A: The adequate intake (AI) for adults is 30 mcg/day. Therapeutic doses for biotin deficiency range from 5-10 mg/day, with possible increases to 15-20 mg/day during puberty. Pediatric doses are lower and vary depending on age.
Q2: How does biotin affect laboratory tests?
A: High doses of biotin can interfere with certain laboratory tests, particularly immunoassays using biotin-streptavidin binding. This can cause falsely elevated or decreased results, affecting tests like thyroid function tests and troponin levels.
Q3: What are the signs and symptoms of biotin deficiency?
A: Symptoms include hair thinning, hair loss, red scaly rash around the eyes, nose, and mouth (seborrheic dermatitis), neurological symptoms (depression, lethargy, hallucinations), and fungal skin infections. In infants, it can cause hypotonia and developmental delay.
Q4: How is biotin deficiency diagnosed?
A: Diagnosis is often based on clinical presentation and dietary history, as there isn’t a reliable and widely available test for biotin levels. However, assessing urinary biotin levels can be considered.
Q5: What foods are rich in biotin?
A: Good sources of biotin include egg yolks, liver, nuts, seeds, sweet potatoes, spinach, and broccoli.
Q6: Is biotin safe during pregnancy and breastfeeding?
A: Biotin is considered safe during pregnancy and breastfeeding when taken in recommended amounts (30 mcg/day during pregnancy, 35 mcg/day during breastfeeding). However, excessive intake should be avoided.
Q7: What are the treatment options for biotinidase deficiency?
A: Lifelong biotin supplementation is the standard treatment for biotinidase deficiency. Doses may range from 5-20 mg/day, adjusted based on age and severity.
Q8: Can biotin improve hair and nail health?
A: While biotin is often marketed for hair and nail health, scientific evidence supporting these claims is limited. Some studies show benefit in specific conditions like uncombable hair syndrome, but more research is needed.
Q9: What should I tell patients about taking biotin before lab tests?
A: Advise patients to discontinue biotin supplements for at least 72 hours, or possibly longer for those with renal impairment or on very high doses, before any lab tests, especially immunoassays, to minimize interference. Ensure communication with the lab regarding potential biotin interference.
