Trade Names:40 Winks- Tablets 50 mg
Trade Names:AllerMax Maximum Strength- Tablets 50 mg
Trade Names:AllerMax- Liquid 12.5 mg per 5 mL
Trade Names:Banophen- Tablets 25 mg- Capsules 25 mg
Trade Names:Banophen Allergy- Elixir 12.5 mg per 5 mL
Trade Names:Benadryl Allergy- Capsules, soft-gels 25 mg- Tablets 25 mg- Tablets, chewable 12.5 mg
Trade Names:Benadryl Children's Allergy- Liquid 12.5 mg per 5 mL
Trade Names:Benadryl Children's Dye-Free- Liquid 12.5 mg per 5 mL
Trade Names:Benadryl Dye-Free Allergy Liquid Gels- Capsules, soft gels 25 mg
Trade Names:Compoz Gel Caps- Capsules 25 mg
Trade Names:Compoz Nighttime Sleep Aid- Tablets 50 mg
Trade Names:Diphen AF- Liquid 12.5 mg per 5 mL
Trade Names:Diphenhist- Solution 12.5 mg per 5 mL
Trade Names:Diphenhist Captabs- Tablets 25 mg
Trade Names:Diphenhydramine- Injection 50 mg/mL
Trade Names:Dormin- Tablets 25 mg- Capsules 25 mg
Trade Names:Genahist- Tablets 25 mg- Capsules 25 mg- Liquid 12.5 mg per 5 mL
Trade Names:Hydramine Cough- Syrup 12.5 mg per 5 mL
Trade Names:Hyrexin-50- Injection 50 mg/mL
Trade Names:Maximum Strength Nytol- Tablets 50 mg
Trade Names:Maximum Strength Sleepinal Capsules and Soft Gels- Capsules 50 mg
Trade Names:Maximum Strength Unisom SleepGels- Capsules 50 mg/mL
Trade Names:Midol PM- Tablets 50 mg
Trade Names:Miles Nervine- Tablets 25 mg
Trade Names:Nytol- Tablets 25 mg
Trade Names:Scot-Tussin Allergy- Liquid 12.5 mg per 5 mL
Trade Names:Siladryl- Elixir 12.5 mg per 5 mL
Trade Names:Simply Sleep- Tablets 25 mg
Trade Names:Sleep-Eze 3- Tablets 25 mg
Trade Names:Sleepwell 2-nite- Tablets 25 mg
Trade Names:Snoozefast- Tablets 50 mg
Trade Names:Sominex- Tablets 25 mg- Tablets 50 mg
Trade Names:Sylphen Cough- Syrup 12.5 mg per 5 mL
Trade Names:Theraflu Thin Strips Multisymptom- Strips, orally disintegrating 25 mg
Trade Names:Triaminic Thin Strips Cough and Runny Nose- Strips, orally disintegrating 12.5 mg
Trade Names:Tusstat- Syrup 12.5 mg per 5 mL
Trade Names:Twilite- Tablets 50 mg
Trade Names:Unisom SleepMelts- Tablets, orally disintegrating 25 mgAllerdryl (Canada)Allernix (Canada)Nytol Extra Strength (Canada)Simply Sleep (Canada)Unisom Extra Strength (Canada)Unisom Extra Strength Sleepgels (Canada)
Competitively antagonizes histamine at H 1 receptor sites.
T max is 1 to 4 h (oral).
Widely distributed, including the CNS. Excreted in breast milk. 98% to 99% protein bound.
Metabolized in the liver.
A portion of the drug excreted unchanged in the urine. The t ½ is 1 to 4 h.
Rapid onset (IV or IM).
6 to 8 h.
Symptomatic relief of perennial and seasonal allergic rhinitis, vasomotor rhinitis and allergic conjunctivitis; temporary relief of runny nose and sneezing caused by common cold; dermatographism; treatment of urticaria and angioedema; amelioration of allergic reactions to blood or plasma; adjunct to epinephrine and other standard measures in anaphylaxis; relief of uncomplicated allergic conditions of immediate type when oral therapy is impossible or contraindicated (parenteral form); treatment and prophylactic treatment of motion sickness (injection only); nighttime sleep aid; management of parkinsonism (including drug-induced) in elderly who are intolerant of more potent agents, in mild cases in other age groups and in combination with centrally acting anticholinergics; control of cough from colds or allergy (syrup formulations).
Hypersensitivity to antihistamines; asthmatic attack; MAO inhibitor therapy; history of sleep apnea; use in newborn or premature infants and in nursing women; use as a local anesthetic.
PO 25 mg every 4 h (max, 150 mg per 24 h).Children (6 to 12 yr of age)
PO 12.5 mg every 4 h (max, 75 mg per 24 h).Children (2 to 6 yr of age)
PO 6.25 mg every 4 h (max, 25 mg per 24 h).Hypersensitivity Reactions, Type 1/Antiparkinsonism/Motion SicknessAdults
PO 25 to 50 mg every 4 to 6 h (max, 300 mg/day). IV/IM 10 to 50 mg IV at a rate not exceeding 25 mg/min or 100 mg deep IM if required (max, 400 mg/day).Children (6 to younger than 12 yr of age)
PO 12.5 to 25 mg every 4 to 6 h (max, 150 mg). IV/IM 5 mg/kg/day or 150 mg/m 2 /day (max, 300 mg divided into 4 doses at a rate not exceeding 25 mg/min or deep IM).Nighttime Sleep AidAdults
PO 50 mg at bedtime.
Store all dose forms at controlled room temperature (59° to 86°F). Protect injection from freezing and light.
May cause additive CNS depression. Avoid alcoholic drinks.Beta-blockers metabolized by CYP2D6 enzyme (eg, metoprolol)
Plasma levels may be elevated by diphenhydramine, increasing CV effects.MAOIs
May increase anticholinergic effects.
Injectable form is incompatible with dexamethasone sodium phosphate, furosemide, iodipamide meglumine, parenteral barbiturates, and phenytoin.
Antihistamines may prevent or diminish otherwise positive reaction to dermal reactivity indicators.
Orthostatic hypotension; palpitations; bradycardia; tachycardia; reflex tachycardia; extrasystoles; faintness.
Drowsiness (often transient); sedation; dizziness; faintness; disturbed coordination.
Nasal stuffiness; dry mouth, nose, and throat; sore throat.
Epigastric distress; nausea; vomiting; diarrhea; constipation; change in bowel habits.
Hemolytic anemia; thrombocytopenia; agranulocytosis.
Increased appetite; weight gain.
Thickening of bronchial secretions; chest tightness; wheezing; respiratory depression.
Hypersensitivity reactions; photosensitivity.
Monitor patient for dizziness and excessive drowsiness. If noted hold therapy. Use caution when administering diphenhydramine by injection. Inadvertent intradermal or subcutaneous administration may cause tissue necrosis.
Category B .
Excreted in breast milk.
Contraindicated in newborn and premature infants. Overdosage may cause hallucinations, convulsions, and death. Antihistamines may diminish mental alertness. In young children, drug may produce paradoxical excitation. Use with caution in children younger than 2 yr of age. Do not use as a nighttime sleep aid in children younger than 12 years of age.
Greater risk of dizziness, excessive sedation, syncope, toxic confusional states, and hypotension in patients older than 60 yr of age. Dosage reduction may be required.
May occur. Have epinephrine 1:1,000 immediately available.
Use with caution in patients with cirrhosis or other liver diseases.
Use with caution in patients predisposed to urinary retention, prostatic hypertrophy, history of bronchial asthma, increased IOP, hyperthyroidism, CV disease, or hypertension. Use with considerable caution in patients with narrow-angle glaucoma, stenosing peptic ulcer, pyloroduodenal obstruction, symptomatic prostatic hypertrophy, or bladder neck obstruction.
Some diphenhydramine products may contain sulfites as preservatives and aspartame as sweetener. Avoid in sulfite-allergic patients and in patients with phenylketonuria, respectively.
Generally not recommended to treat lower respiratory tract symptoms, including asthma.
Circulatory collapse; cardiac arrest; respiratory depression or arrest; toxic psychosis; coma; stupor; seizures; ataxia; anxiety; incoherence; hyperactivity; combativeness; anhidrosis; fever; hot, dry, or flushed skin; dry mucous membranes; dysphagia; decreased bowel sounds; dilated and sluggish pupils.
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