Note: This document contains side effect information about diphenhydramine. Some of the dosage forms listed on this page may not apply to the brand name Unisom SleepMelts.
More frequent side effects include: sedated state and thickening of bronchial secretions. See below for a comprehensive list of adverse effects.
Applies to diphenhydramine: oral capsules and tablets, parenteral injection
Side effects include:
Sedation, sleepiness, dizziness, disturbed coordination, epigastric distress, thickening of bronchial secretions.
Applies to diphenhydramine: compounding powder, injectable solution, oral capsule, oral disintegrating strip, oral liquid, oral tablet, oral tablet chewable, oral tablet disintegrating
The most commonly reported side effects included somnolence, dizziness, and incoordination.
Common (1% to 10%): Sedation/somnolence/sleepiness, drowsiness, unsteadiness, dizziness, headache, attention disturbance
Rare (0.01% to 0.1%): Extrapyramidal effects, tremor, convulsions
Frequency not reported: Paresthesia, dyskinesia/muscle dyskinesia, vertigo, neuritis, incoordination, psychomotor impairment, activation of epileptogenic foci
Drowsiness usually diminishes after a few days.
Common (1% to 10%): Dry mouth
Frequency not reported: Gastrointestinal disturbance, nausea, vomiting, constipation, diarrhea, dyspepsia, epigastric distress
Common (1% to 10%): Fatigue
Frequency not reported: Lassitude, tinnitus, acute labyrinthitis, asthenia, chills, impaired performance (including impaired driving, work, and/or information processing)
Rare (0.01% to 0.1%): Confusion, depression, sleep disturbances
Frequency not reported: Paradoxical excitation/excitation, agitation, increased energy, restlessness, nervousness, euphoria, anxiety, hallucinations, insomnia, irritability
Rare (0.01% to 0.1%): Palpitations, hypotension, arrhythmia
Frequency not reported: Tachycardia, chest tightness, extrasystoles
Rare (0.01% to 0.1%): Blood disorders
Frequency not reported: Hemolytic anemia, thrombocytopenia, agranulocytosis
Rare (0.01% to 0.1%): Hypersensitivity reactions
Frequency not reported: Angioedema, anaphylactic shock
Rare (0.01% to 0.1%): Liver dysfunction
Frequency not reported: Rash, urticaria, skin rashes, erythema, photosensitivity, pruritus, drug rash, excessive perspiration
Frequency not reported: Dyspnea, thickening of bronchial secretions, throat tightening, wheezing, nasal stuffiness, dry nose or throat
Frequency not reported: Urinary hesitancy/difficulty/retention, dysuria, early menses
Frequency not reported: Blurred vision, dry eyes, diplopia
Frequency not reported: Increased appetite, anorexia
Frequency not reported: Muscle twitching/weakness
Medically reviewed by BestRx Medical Team Last updated on 1/1/2020.
Source: Drugs.com Unisom Sleepmelts