Usage
- Medical Conditions: Aminobenzoic acid (PABA) is FDA-approved for treating Peyronie’s disease (a condition causing curved, painful erections) and for use as a sunscreen to prevent sunburn. It has historically been used for scleroderma (hardening of skin and connective tissues), but its efficacy for this purpose is not well-established. It has also been used to treat vitiligo but with limited evidence.
- Pharmacological Classification: Sunscreen agent, antifibrotic agent.
- Mechanism of Action: The exact mechanism of action in Peyronie’s disease is unclear, but it is thought to involve antifibrotic properties, potentially by increasing oxygen uptake in tissues. As a sunscreen, PABA absorbs ultraviolet radiation, preventing it from reaching and damaging the skin.
Alternate Names
- Para-aminobenzoic acid (PABA)
- Vitamin B10 (outdated classification)
- Brand names: Potaba (potassium salt formulation)
How It Works
- Pharmacodynamics: In Peyronie’s disease, PABA is thought to exert antifibrotic effects, potentially by increasing tissue oxygenation. As a sunscreen, it absorbs UVB radiation.
- Pharmacokinetics:
- Absorption: Absorbed through the gastrointestinal tract when taken orally. Absorption through the skin is minimal when used as a sunscreen.
- Metabolism: Metabolized in the liver.
- Elimination: Primarily excreted in the urine.
- Mode of Action: Not fully elucidated for Peyronie’s disease. UVB absorption in sunscreen use.
- Receptor binding, enzyme inhibition, neurotransmitter modulation: Specific interactions not well-characterized.
Dosage
Standard Dosage
Adults:
- Peyronie’s Disease: 12 grams per day orally, divided into four to six doses with meals or snacks.
- Sunscreen: Apply liberally to exposed skin 30 minutes before sun exposure. Reapply every two hours, or after swimming or sweating.
Children:
- Peyronie’s Disease: 220 mg/kg of body weight per day orally, divided into four to six doses with meals or snacks. Pediatric doses above this level can be unsafe, even fatal.
- Sunscreen: Apply as directed on product labeling.
Special Cases:
- Elderly Patients: Dose adjustments may be necessary based on renal function.
- Patients with Renal Impairment: Dose reduction may be needed.
- Patients with Hepatic Dysfunction: Dose adjustment may be required.
- Patients with Comorbid Conditions: Use with caution in patients with kidney disease.
Clinical Use Cases
PABA is not typically used for intubation, surgical procedures, mechanical ventilation, ICU use, or emergency situations. Its primary clinical uses are for Peyronie’s disease and as a sunscreen.
Dosage Adjustments:
Adjustments should be made for renal or hepatic impairment.
Side Effects
Common Side Effects
- Nausea
- Vomiting
- Upset stomach
- Anorexia
- Rash (especially with topical use)
Rare but Serious Side Effects
- Liver toxicity (with high doses)
- Kidney damage (with high doses)
- Blood disorders (with high doses)
- Allergic reactions (including hives, swelling, difficulty breathing, anaphylaxis)
- Hypoglycemia (low blood sugar)
Long-Term Effects
Chronic complications from prolonged use are not well-studied.
Adverse Drug Reactions (ADR)
Severe allergic reactions, liver or kidney damage require immediate medical attention.
Contraindications
- Hypersensitivity to PABA or any component of the formulation.
- Sulfonamide antibiotic use (PABA antagonizes their effects).
- Dapsone use (PABA may reduce its effectiveness).
- Severe kidney disease.
Drug Interactions
- Sulfonamide antibiotics: PABA reduces their effectiveness.
- Dapsone: PABA may decrease its efficacy.
- Medications affecting liver enzymes: Potential for altered metabolism of both drugs.
Pregnancy and Breastfeeding
- Pregnancy Safety Category: Not formally categorized. Limited data available. Generally avoid oral use during pregnancy. Topical use on the skin is likely safe.
- Breastfeeding: Unknown if excreted in breast milk. Exercise caution.
Drug Profile Summary
- Mechanism of Action: Antifibrotic (Peyronie’s), UVB absorption (sunscreen).
- Side Effects: Nausea, vomiting, anorexia, rash, liver/kidney toxicity (high doses), allergic reactions.
- Contraindications: Hypersensitivity, sulfonamide use, dapsone use, severe kidney disease.
- Drug Interactions: Sulfonamides, dapsone, liver enzyme-altering drugs.
- Pregnancy & Breastfeeding: Limited safety data; avoid oral use in pregnancy.
- Dosage: Peyronie’s: Adults 12g/day divided, Children 220mg/kg/day divided. Sunscreen: apply liberally.
- Monitoring Parameters: Liver function tests (with high-dose oral PABA).
Popular Combinations
PABA is not typically used in combination therapies for Peyronie’s disease. It may be included in multivitamin supplements.
Precautions
- General Precautions: Assess for allergies, renal function.
- Specific Populations: Avoid oral PABA in pregnancy, exercise caution during breastfeeding. Carefully consider dosage in children and elderly patients.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Aminobenzoic Acid?
A: For Peyronie’s disease in adults: 12 grams/day orally, divided into 4-6 doses. For children: 220 mg/kg/day orally, divided into 4-6 doses. For sunscreen use, follow product label instructions.
Q2: What are the common side effects of Aminobenzoic Acid?
A: Common side effects include nausea, vomiting, upset stomach, loss of appetite, and rash.
Q3: Is Aminobenzoic Acid safe during pregnancy?
A: Topical application is likely safe during pregnancy and breastfeeding. Oral use should be avoided during pregnancy due to limited safety data.
Q4: What are the serious side effects of Aminobenzoic Acid?
A: Serious side effects, usually associated with high doses, include liver and kidney damage, blood disorders, allergic reactions, and hypoglycemia.
Q5: What medications interact with Aminobenzoic Acid?
A: PABA interacts significantly with sulfonamide antibiotics and dapsone, decreasing their effectiveness. It may also interact with medications that affect liver enzymes.
Q6: Can children take Aminobenzoic Acid?
A: Yes, but the dosage needs careful adjustment based on body weight (220 mg/kg/day divided into 4-6 doses for Peyronie’s Disease). Doses above this level can be dangerous, even fatal. Topical sunscreen use should follow product labeling.
Q7: What is the mechanism of action of Aminobenzoic Acid in Peyronie’s disease?
A: The exact mechanism is not fully understood, but it’s believed to involve antifibrotic effects, possibly by enhancing oxygen uptake in tissues.
Q8: Is Aminobenzoic Acid a vitamin?
A: While previously classified as vitamin B10, it is now considered a nonessential nutrient.
Q9: How should Aminobenzoic Acid be administered for Peyronie’s disease?
A: Orally, with food, in divided doses throughout the day to minimize gastrointestinal upset.
