Diphenhydramine Hydrochloride Prefilled Syringes for Injection 50 mg/mL, 24 Pack (Rx)

Yes, diphenhydramine can be administered by injection—either intravenously (IV) or intramuscularly (IM)—when rapid antihistamine effects are needed, or when oral intake is not possible.

Yes, injectable diphenhydramine is the same medication as Benadryl, delivering the same antihistamine effects but in a form for faster, more direct relief.

Diphenhydramine injection is commonly used for: Severe allergic reactions / anaphylaxis Acute urticaria (hives) or itching Drug-induced extrapyramidal symptoms (dyskinesia) Motion sickness or nausea Premedication for chemotherapy, transfusions, or contrast allergy prevention Adjunct in insomnia or sedation (hospital setting)

Healthcare professionals administer diphenhydramine by IV or IM injection. IV should be given slowly (25 mg/min) to avoid side effects. IM injection is given deep into a large muscle (thigh, gluteal).

IM: Upper outer quadrant of the gluteal muscle, or deltoid. IV: Directly into a vein after proper dilution and slow injection.

Adults: 10–50 mg per dose, every 4–6 hours; max 400 mg/day. Children (over 12 years): Similar to adult dosing; always follow doctor’s advice. Never self-inject—always use under medical supervision.

Effects generally last 4–6 hours. Symptom relief is rapid and can be felt within minutes of administration.

Onset is typically within 2–10 minutes IV, or 20–30 minutes IM. Injected diphenhydramine works much faster than oral tablets.

Yes. Sedation or drowsiness is a common side effect, as with all first-generation antihistamines.

No. Injectable form is not intended for oral use—**dosage and safety may differ. Only use as prescribed and administered by a healthcare professional.

This refers to the concentration: 1% solution is 10 mg/mL. The most common forms are 1% or 50 mg/mL for hospital and emergency use.

Yes. Diphenhydramine is the most widely used injectable antihistamine for emergencies, chemotherapy premedication, and acute allergic reactions.

Children under 2 years old Those with severe hypertension, narrow-angle glaucoma, asthma, urinary retention, or enlarged prostate Pregnant or breastfeeding women (consult a doctor) Patients taking MAO inhibitors or other sedatives

Benadryl (diphenhydramine) is given to prevent allergic reactions to chemotherapy agents or to reduce nausea/symptoms related to chemo drugs and infusions.

No. Diphenhydramine is an antihistamine; cortisone is a corticosteroid. They are different drug classes but can be used together for severe allergic reactions.

Common risks include: Drowsiness, sedation, dizziness Dry mouth, blurred vision, urinary retention Nausea, headache, hypotension Allergic reaction (rare), confusion (elderly)

Coverage is typically 4–6 hours. Repeat doses may be given if needed (per doctor’s direction).