Find BENADRYL® dosage information for adults, children, and toddlers and learn how much you and your family should take with our allergy medicine product-dosing guide. Dosage Forms: Oral, IM, IV Common Trade Names: Benadryl Adult Dosing Allergic reaction Oral: 25-50mg q4-8h, max 300mg/day IM/IV: 10-50mg/dose Parkinsonian symptoms Oral: 25-50mg tid-QID IM/IV: 10-50mg/dose Insomnia: 50mg PO qhs Injectable 1% diphenhydramine (10 mg/mL) can be used as a local anesthestic alternative to ester/amide anesthetics [1] Detailed Diphenhydramine dosage information for adults and children. Includes dosages for Insomnia, Allergic Rhinitis, Allergic Reaction and more; plus renal, liver and dialysis adjustments. Calculate the appropriate diphenhydramine (Benadryl®) dose based on body weight, age, and formulation. This tool supports liquid, chewable, tablet, and capsule forms for both children and adults. The recommended adult Benadryl dosage for allergies is 1 to 2 tablets or capsules by mouth every 4 to 6 hours as needed. You shouldn’t take more than 6 doses (300 mg) in a 24-hour period. For adults with common cold symptoms, the typical dosage of Benadryl is 25 to 50 mg (one to two tablets) taken every 4 to 6 hours, or as directed by your doctor. You should not take Benadryl and Zyrtec together unless directed by your doctor. Both are antihistamines, and combining them can increase risks for drowsiness, confusion, and other side effects. Medscape - Hypersensitivity reactions, insomnia, antihistamine-specific dosing for Benadryl, Nytol (diphenhydramine), frequency-based adverse effects, comprehensive interactions. Find the recommended amount of Benadryl to give your child based on age and weight using the St. Louis Children's Hospital Benadryl dosage chart. Diphenhydramine (Benadryl) Dosage Table For treatment of allergic reactions, nasal allergies, and hives. AGE LIMITS: Do not use under 1 year of age unless directed by provider are more accurate than teaspoons. If possible, use the syringe or dropper that comes with the medicine. If no.