Dosing of Phenylpropanolamine and Brompheniramine
Critical Safety Warning
Phenylpropanolamine (PPA) has been withdrawn from the U.S. market due to increased risk of hemorrhagic stroke and should not be used in humans. While historical FDA labeling exists for veterinary use, this medication is no longer considered safe for human consumption based on documented severe adverse events including intracranial hemorrhages and deaths 1.
Historical Human Dosing (No Longer Recommended)
Phenylpropanolamine (Withdrawn from Market)
- Maximum daily dose: 75 mg for weight control, not to exceed 12 weeks of use 2
- Severe adverse events: 142 documented adverse drug reactions including 24 intracranial hemorrhages, 8 seizures, and 8 deaths (most from stroke) occurred even at recommended doses 1
- Hypertensive crisis risk: Double dosing (150 mg) causes clinically significant hypertension into dangerous ranges 3
- Psychiatric complications: 37 cases of acute mania, paranoid schizophrenia, and organic psychosis attributed to PPA, particularly in those with psychiatric history, children under 6, and postpartum women 4
Brompheniramine (Current FDA-Approved Dosing)
Adults and children ≥12 years: 10 mL (2 teaspoonfuls) every 4 hours 5
Children 6 to <12 years: 5 mL (1 teaspoonful) every 4 hours 5
Children 2 to <6 years: 2.5 mL (½ teaspoonful) every 4 hours 5
Infants 6 months to <2 years: Dosage must be established by a physician 5
Maximum frequency: Do not exceed 6 doses in 24 hours 5
Clinical Considerations
- Combination products: Historical combination products containing both PPA and brompheniramine were associated with 85% of adverse reactions occurring with over-the-counter formulations 1
- High-risk populations: Females and patients under 30 years accounted for two-thirds of all PPA-related adverse reactions 1
- Caffeine interaction: Co-ingestion of 75 mg PPA with 400 mg caffeine resulted in significant hypertensive episodes 3
Current Practice Recommendation
Use brompheniramine alone according to FDA dosing guidelines 5. Avoid any products containing phenylpropanolamine due to unacceptable stroke risk and documented mortality 1, 3.