Diphenhydramine hydrochloride drug information

DOSAGE AND ADMINISTRATION DOSAGE SHOULD BE INDIVIDUALIZED ACCORDING TO THE NEEDS AND THE RESPONSE OF THE PATIENT. A single oral dose of diphenhydramine hydrochloride is quickly absorbed with maximum activity occurring in approximately one hour. The duration of activity following an average dose of diphenhydramine hydrochloride is from four to six hours. Adults 25 to 50 mg three to four times daily. The nightime sleep aid dosage is 50 mg at bedtime. Pediatric Patients, other than premature infants and neonates 12.5 mg to 25 mg three or four times daily. Maximum daily dosage not to exceed 300 mg. For physicians who wish to calculate the dose on the basis of body weight or surface area, the recommended dosage is 5 mg/kg/24 hours or 150 mg/m 2 /24 hours. Data are not available on the use of diphenhydramine hydrochloride as a nighttime sleep-aid in children under 12 years. The basis for determining the most effective dosage regimen will be the response of the patient to medication and the condition under treatment. In motion sickness, full dosage is recommended for prophylactic use, the first dose to be given 30 minutes before exposure to motion and similar doses before meals and upon retiring for the duration of exposure

CONTRAINDICATIONS Use in Neonates or Premature Infants This drug should not be used in neonates or premature infants. Use in Nursing Mothers Because of the higher risk of antihistamines for infants generally, and for neonates and prematures in particular, antihistamine therapy is contraindicated in nursing mothers. Antihistamines are also contraindicated in the following conditions Hypersensitivity to diphenhydramine hydrochloride and other antihistamines of similar chemical structure.

WARNINGS Antihistamines should be used with considerable caution in patients with narrow-angle glaucoma, stenosing peptic ulcer, pyloroduodenal obstruction, symptomatic prostatic hypertrophy, or bladder-neck obstruction. Use in Pediatric Patients In pediatric patients, especially, antihistamines in overdosage may cause hallucinations, convulsions, or death. As in adults, antihistamines may diminish mental alertness in pediatric patients. In the young pediatric patient, particularly, they may produce excitation. Use in the Elderly (approximately 60 years or older) Antihistamines are most likely to cause dizziness, sedation, and hypotension in elderly patients.

ADVERSE REACTIONS The most frequent adverse reactions are underscored. 1. General: Urticaria, drug rash, anaphylactic shock, photosensitivity, excessive perspiration, chills, dryness of the mouth, nose and throat. 2. Cardiovascular System: Hypotension, headache, palpitations, tachycardia, extrasystoles. 3. Hematologic System: Hemolytic anemia, thrombocytopenia, agranulocytosis. 4. Nervous System: Sedation, sleepiness, dizziness, disturbed coordination, fatigue, confusion, restlessness, excitation, nervousness, tremor, irritability, insomnia, euphoria, paresthesia, blurred vision, diplopia, vertigo, tinnitus, acute labyrinthitis, neuritis, convulsions. 5. GI System: Epigastric distress, anorexia, nausea, vomiting, diarrhea, constipation. 6. GU System: Urinary frequency, difficult urination, urinary retention, early menses. 7. Respiratory System: Thickening of bronchial secretions, tightness of chest or throat and wheezing, nasal stuffiness. To report SUSPECTED ADVERSE REACTIONS, contact Annora Pharma Limited at 1-866-495-1995 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

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.

DESCRIPTION Diphenhydramine hydrochloride USP is an antihistamine drug having the chemical name 2-(diphenylmethoxy)-N,N-dimethylethanamine hydrochloride and has the molecular formula C 17 H 21 NO•HCl (molecular weight 291.82). It occurs as a white, odorless, crystalline powder. Slowly darkens on exposure to light and is freely soluble in water, alcohol and in chloroform. Sparingly soluble in acetone. Very slightly soluble in benzene and in ether. The structural formula is as follows: Each 5 mL contains 12.5 mg of diphenhydramine hydrochloride USP and alcohol 14% for oral administration. Inactive Ingredients: cassia cinnamon flavour (contains cassia bark oil, cinnamic aldehyde, cinnamon leaf oil, eugenol and glyceryl triacetate), citric acid monohydrate, D&C red No. 33, ethyl alcohol dehydrated, FD&C red No. 40, purified water, sucrose and trisodium citrate dihydrate. diphenhydraminehclstruct

CLINICAL PHARMACOLOGY Diphenhydramine hydrochloride is an antihistamine with anticholinergic (drying) and sedative effects. Antihistamines appear to compete with histamine for cell receptor sites on effector cells. A single oral dose of diphenhydramine hydrochloride is quickly absorbed with maximum activity occurring in approximately one hour. The duration of activity following an average dose of diphenhydramine hydrochloride is from four to six hours. Diphenhydramine is widely distributed throughout the body, including the CNS. Little, if any, is excreted unchanged in the urine; most appears as the degradation products of metabolic transformation in the liver, which are almost completely excreted within 24 hours.

PRECAUTIONS 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.

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.

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.

OVERDOSAGE Antihistamine overdosage reactions may vary from central nervous system depression to stimulation. Stimulation is particularly likely in pediatric patients. Atropine-like signs and symptoms, dry mouth; fixed, dilated pupils; flushing and gastrointestinal symptoms may also occur. If vomiting has not occurred spontaneously, the patient should be induced to vomit. This is best done by having him drink a glass of water or milk after which he should be made to gag. Precaution against aspiration must be taken, especially in infants and children. If vomiting is unsuccessful, gastric lavage is indicated within 3 hours after ingestion and even later if large amounts of milk or cream were given beforehand. Isotonic or 1/2 isotonic saline is the lavage solution of choice. Saline cathartics, as milk of magnesia, by osmosis draw water into the bowel and therefore are valuable for their action in rapid dilution of bowel content. Stimulants should not be used. Vasopressors may be used to treat hypotension.

HOW SUPPLIED Each 5 mL of Diphenhydramine Hydrochloride Oral Solution, USP- Clear, purple to red solution with cinnamon flavour, contains 12.5 mg diphenhydramine hydrochloride with 14% alcohol and is supplied as: NDC 31722-600-11 118 mL (4 oz) bottle NDC 31722-600-31 Box of 100 (10 cartons containing 10 x 5 mL unit dose cups in each.) NDC 31722-601-31 Box of 100 (10 cartons containing 10 x 10 mL unit dose cups in each.) STORAGE Store at 20° to 25°C (68° to 77°F). [See USP Controlled Room Temperature]. Protect from freezing and light. Manufactured for: Camber Pharmaceuticals, Inc. Piscataway, NJ 08854. By: Annora Pharma Pvt. Ltd. Sangareddy - 502313, Telangana, India. Revised: 05/2026 camberlogo