Diphenhydramine Hydrochloride



Diphenhydramine Hydrochloride is indicated for allergy of diverse origins such as-
  • Cutaneous allergies
  • Urticaria
  • Angioneurotic edema
  • Relief of coughing
  • Laminitis
  • Allergic reactions to medicaments
  • Anaphylactic shock
  • Insect bites
  • Eczema
  • Pruritis
  • Photosensitization


Diphenhydramine Hydrochloride is an antihistaminic drug. It also has substantial sedative, anti-cholinergic, anti-tussive and anti-emetic effects. It inhibits histamine release by blocking H 1 receptors.

Dosage & Administration

Bolus: For oral administration only.
  • Large animals: 1 bolus/125-250 kg body weight.
  • Small animals: 1 mg/kg body weight.
  • Dogs, Cats: 2-4 mg/kg body weight 2-3 times daily.
Injection: For IV/IM use only.
  • Large animals: 1.25-2.50 ml/100 kg body weight (0.25 mg-0.50 mg/kg body weight)
  • Small animals: 1 ml/40 kg body weight (0.5 mg /kg body weight).
  • Dog: 0.25 ml/5 kg body weight (1 mg/kg body weight)
  • Cat: 0.1 ml/2 kg body weight (1 mg/kg body weight) Or, as Directed By Veterinary Physician.


Animals hypersensitive to Diphenhydramine Hydrochloride or any other antihistamine.

Side Effects

CNS depression (drowsiness), anticholinergic (dry mouth, urinary retention), diarrhea etc. may occur in some cases.

Pregnancy & Lactation

Use in pregnancy has not been determined. However, risk & necessity should be considered during administration in pregnant & lactating animal.

Precautions & Warnings

Withdrawal Period: Meat-7 days, Milk-2 days.

Storage Conditions

Store in a cool and dry place, protected from light. Keep all medicines out of reach of children.