Vicks QlearQuil Nighttime Allergy Relief Side Effects
Generic name: diphenhydramine
Medically reviewed by Drugs.com. Last updated on Oct 3, 2023.
Note: This document contains side effect information about diphenhydramine. Some dosage forms listed on this page may not apply to the brand name Vicks QlearQuil Nighttime Allergy Relief.
Applies to diphenhydramine: oral capsules and tablets, parenteral injection.
Side effects include:
Sedation, sleepiness, dizziness, disturbed coordination, epigastric distress, thickening of bronchial secretions.
For Healthcare Professionals
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.[Ref]
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[Ref]
Drowsiness usually diminishes after a few days.[Ref]
Common (1% to 10%): Dry mouth
Common (1% to 10%): Fatigue
Frequency not reported: Lassitude, tinnitus, acute labyrinthitis, asthenia, chills, impaired performance (including impaired driving, work, and/or information processing)[Ref]
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[Ref]
Rare (0.01% to 0.1%): Blood disorders
Rare (0.01% to 0.1%): Hypersensitivity reactions
Rare (0.01% to 0.1%): Liver dysfunction[Ref]
Frequency not reported: Urinary hesitancy/difficulty/retention, dysuria, early menses[Ref]
Frequency not reported: Blurred vision, dry eyes, diplopia[Ref]
Frequency not reported: Increased appetite, anorexia[Ref]
Frequency not reported: Muscle twitching/weakness[Ref]
Frequently asked questions
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- Diphenhydramine Hydrochloride vs Citrate: What's the difference?
More about Vicks QlearQuil Nighttime Allergy Relief (diphenhydramine)
- Check interactions
- Compare alternatives
- Reviews (1)
- Imprints, shape & color data
- Latest FDA alerts (2)
- Dosage information
- During pregnancy
- Drug class: antihistamines
Related treatment guides
1. Product Information. Benadryl (diphenhydramine). Parke-Davis. 2002.
2. Product Information. Benadryl Children's Allergy Fastmelt (diphenhydrAMINE). Pfizer U.S. Pharmaceuticals Group. 2022.
3. Cerner Multum, Inc. UK Summary of Product Characteristics.
4. Cerner Multum, Inc. Australian Product Information.
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
Some side effects may not be reported. You may report them to the FDA.