Diphenhydramine

DOSAGE AND ADMINISTRATION THIS PRODUCT IS FOR INTRAVENOUS OR INTRAMUSCULAR ADMINISTRATION ONLY. Diphenhydramine hydrochloride injection, USP is indicated when the oral form is impractical. DOSAGE SHOULD BE INDIVIDUALIZED ACCORDING TO THE NEEDS AND THE RESPONSE OF THE PATIENT.

Pediatric Patients, Other Than Premature Infants and Neonates 5 mg/kg/24 hours or 150 mg/m 2 /24 hours. Maximum daily dosage is 300 mg. Divide into four doses, administered intravenously at a rate generally not exceeding 25 mg/min, or deep intramuscularly.

Adults 10 mg to 50 mg intravenously at a rate generally not exceeding 25 mg/min, or deep intramuscularly; 100 mg if required; maximum daily dosage is 400 mg. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.

ADVERSE REACTIONS

The most frequent adverse reactions are italicized. General Urticaria; drug rash; anaphylactic shock; photosensitivity; excessive perspiration; chills; dryness of mouth, nose and throat. Cardiovascular System Hypotension, headache, palpitations, tachycardia, extrasystoles.

Hematologic System Hemolytic anemia, thrombocytopenia, agranulocytosis. 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.

Gastrointestinal System Epigastric distress , anorexia, nausea, vomiting, diarrhea, constipation. Genitourinary System Urinary frequency, difficult urination, urinary retention, early menses. Respiratory System Thickening of bronchial secretions , tightness of chest and wheezing, nasal stuffiness.

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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. Local necrosis has been associated with the use of subcutaneous or intradermal use of intravenous diphenhydramine.

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 more likely to cause dizziness, sedation and hypotension in elderly patients.

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.

Use as a Local Anesthetic Because of the risk of local necrosis, this drug should not be used as a local anesthetic. Antihistamines are also Contraindicated in the Following Conditions Hypersensitivity to diphenhydramine hydrochloride and other antihistamines of similar chemical structure.