About DIPHENHYFR AMINE HCL 100MG/100M
Sedating antihistamine
Used for
- Relief of sneezing, runny nose, and other allergy symptoms
- Relief of hives and itching
- Prevention and treatment of motion sickness
- Short-term relief of occasional sleeplessness
Usual adult dose
For allergies: 25–50 mg every 4–6 hours; maximum 300 mg daily.
Usual dose in children
Ages 6–11, for allergies: 12.5–25 mg every 4–6 hours; maximum 150 mg daily. Not for routine use under age 6.
Common side effects
- Drowsiness, dizziness, and reduced alertness
- Dry mouth, nose, or throat
- Constipation, blurred vision, or difficulty urinating
- Excitement or restlessness, especially in children
Important warnings
- May impair driving and operating machinery
- Extra caution with glaucoma, urinary retention, or enlarged prostate
- Older adults have greater confusion and fall risks
- Do not combine with other diphenhydramine-containing products
Pregnancy
Occasional use is generally considered low risk; prolonged or high-dose use requires clinical review.
Breastfeeding
Occasional small doses are unlikely to harm; repeated use may cause infant drowsiness or reduce milk supply.
Interactions
- Alcohol increases drowsiness and impairment
- Opioids, sleeping medicines, and sedatives increase sedation
- Other anticholinergic medicines increase constipation, confusion, and urinary retention
- MAO inhibitors can intensify and prolong adverse effects
AI-generated from general medical knowledge, not from this product's official leaflet. It may be incomplete or out of date. Not medical advice — ask a pharmacist or doctor before making any decision.