Generic name:diphenhydramine hydrochlorideBrand name:BenadrylPreparations:PO 25-50 mg q4-6 hr, 50mg 20-30 mins before bedtimeCLASSIFICATION: Antiparkinsonian drugACTION: Antagonizes the effect of histamine at H1 receptor sites; does not bind or inactivate histamineINDICATION / USES:parkinsonism or drug-induced extrapyramidal effects

COMMON ADVERSE EFFECTS:CNS: headache, fatigue, anxiety, tremors, vertigo, confusion, depression, seizures, hallucinationsCV: tachycardia, palpitations, orthostaic hypotension, heart failureEENT: blurred vision GI: dry mouth, nausea, vomiting, constipation, flatulence GU: urinary hesitancy or frequency, urine retention Hematologic: leukopenia Skin: photosensitivity, dermatitisCONTRA-INDICATIONS: cardiac disease or hypertension glaucoma gastric or duodenal ulcersNURSING CONSIDERATIONS: Caution the client that the medication may cause drowsiness, creating difficulties or hazards or other activities that require alertness. Tell the client to take the medication with food to decrease GI upset. Explain to the client that arising quickly form a lying or sitting position may cause orthostatic hypotension. When taking these medications, the client needs to have blood cells counts, renal function, hepatic function, and blood pressure monitored. Adverse effects of these drugs occur more commonly in elderly clients. Explain to the client that use of these drugs in warm weather may increase the likelihood of heatstroke.