Diphenhydramine

Diphenhydramine is an antihistamine used for treating allergic reactions. Histamine is released by the body during several types of allergic reactions and--to a lesser extent--during some viral infections, such as the common cold. When histamine binds to receptors on cells, it stimulates changes within the cells that lead to the release of chemicals that cause sneezing, itching, and increased mucus production. Antihistamines compete with histamine for cell receptors and bind to the receptors without stimulating the cells. In addition, they prevent histamine from binding and stimulating the cells. Diphenhydramine also blocks the action of acetylcholine (anticholinergic effect) and is used as a sedative because it causes drowsiness. The FDA originally approved diphenhydramine in 1946.

BRAND NAME:

Benadryl, Sominex, Unisom, Nytol, and several others

GENERIC AVAILABLE:

Yes

PRESCRIPTION AVAILABLE:

No. Yes (Injection)

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Available in:
Ultratabs® tablets: Box of 24's, 48's, & 100's
Kapseals® capsules: Box of 24's & 48's

FDA rev date: 7/1/1997

Diphenhydramine is used in the treatment of:

• Anxiety Disorders
• Motion Sickness
• Nausea
• Rhinitis, Allergic, Perennial
• Sleep Initiation and Maintenance Disorders
• Urticaria

This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.

This is not a complete list of Diphenhydraminedrug interactions. Ask your doctor or pharmacist for more information.

Diphenhydramine is available in the following forms:

• Disintegrating Tablet
• Extended Release Capsule
• Extended Release Suspension
• Extended Release Tablet
• Injectable Solution
• Mouthwash
• Mouthwashes
• Oral Capsule
• Oral Powder
• Oral Solution
• Oral Strip
• Oral Suspension
• Oral Tablet
• Prefilled Syringe
• Topical Cream
• Topical Gel
• Topical Lotion
• Topical Ointment
• Topical Solution
• Topical Spray

• Allergy (Allergies)
• Allergy Drugs: Prescription and OTC
• Drug Side Effects
• Eczema
• Hives (Urticaria & Angioedema)
• Itch (Itching or Pruritus)
• Parkinson's Disease
• Scabies
• Sleep Disorders (How to Get a Good Night's Sleep)

Diphenhydramine hydrochloride in the oral form is effective for the following indications:

Antihistaminic

For allergic conjunctivitis due to foods; mild, uncomplicated allergic skin manifestations of urticaria and angioedema; amelioration of allergic reactions to blood or plasma; dermatographism; as therapy for anaphylactic reactions adjunctive to epinephrine and other standard measures after the acute manifestations have been controlled.

Motion Sickness

For active and prophylactic treatment of motion sickness.

Antiparkinsonism

For parkinsonism (including drug-induced) in the elderly unable to tolerate more potent agents; mild cases of parkinsonism (including drug-induced) in other age groups; in other cases of parkinsonism (including drug-induced) in combination with centrally acting anticholinergic agents.

Nighttime Sleep-aid.

General

Diphenhydramine hydrochloride has an atropine-like action and therefore, should be used with caution in patients with a history of bronchial asthma, increased intraocular pressure, hyperthyroidism, cardiovascular disease or hypertension. Use with caution in patients with lower respiratory disease including asthma.

Information for Patients

Patients taking Diphenhydramine hydrochloride should be advised that this drug may cause drowsiness and has an additive effect with alcohol. Patients should be warned about engaging in activities requiring mental alertness such as driving a car or operating appliances, machinery, etc.

Drug Interactions

Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc.). MAO inhibitors prolong and intensify the anticholinergic (drying) effects of antihistamines.

Carcinogenesis, Mutagenesis, Impairment of Fertility

Long-term studies in animals to determine mutagenic and carcinogenic potential have not been performed.

Pregnancy

Reproduction studies have been performed in rats and rabbits at doses up to 5 times the human dose and have revealed no evidence of impaired fertility or harm to the fetus due to Diphenhydramine hydrochloride. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.

Pediatric Use

Diphenhydramine hydrochloride should not be used in neonates and premature infants (see CONTRAINDICATIONS).

Diphenhydramine hydrochloride may diminish mental alertness, or, in the young pediatric patient, cause excitation. Overdosage may cause hallucinations, convulsions, or death (see WARNINGS and OVERDOSAGE).

See also DOSAGE AND ADMINISTRATION section.

Delivers 10 mL
NDC 0121-0978-10

Diphenhydramine HCl 

ORAL SOLUTION USP

25 mg/10 mL

Alcohol 14%
FOR INSTITUTIONAL USE ONLY

Store at 20° to 25°C (68° to 77°F).
[See USP Controlled Room Temperature].
Rx ONLY
PHARMACEUTICAL ASSOCIATES, INC.
GREENVILLE, SC 29605
SEE INSERT

A04891001