Meclizine Contraindications

Meclizine is contraindicated only in patients with known hypersensitivity to meclizine or any of its inactive ingredients. 1

Absolute Contraindication

Hypersensitivity reactions: The sole FDA-labeled contraindication is documented hypersensitivity to meclizine or any inactive ingredient in the formulation, which can include anaphylactic reactions 1

While not formally contraindicated, meclizine should be prescribed with extreme caution or avoided in the following clinical scenarios:

Asthma: Anticholinergic effects may thicken bronchial secretions and worsen respiratory function 1
Glaucoma: Particularly narrow-angle glaucoma, where anticholinergic properties can precipitate acute angle closure 1
Prostatic hypertrophy: Urinary retention risk increases due to anticholinergic effects 1

Concurrent CNS depressants: Coadministration with alcohol or other CNS depressants results in additive sedation and increased risk of falls 1
Operating machinery: Drowsiness is a common adverse effect requiring caution with driving or dangerous activities 1

Older adults: First-generation antihistamines like meclizine cause significant psychomotor impairment, increasing fall risk, fractures, and subdural hematomas in elderly patients 2
Anticholinergic burden: Dry mouth, constipation, urinary retention, and cognitive impairment are particularly problematic in older adults 2
Next-day impairment: Sedating effects persist beyond plasma levels, causing functional impairment even when taken at bedtime 2

Severe liver disease: Meclizine should be avoided as it can precipitate hepatic encephalopathy in patients with cirrhosis, particularly those with Child-Pugh C classification 2
Mild-to-moderate cirrhosis: If used, requires close monitoring for encephalopathy signs (confusion, asterixis, altered sleep-wake cycle) and assessment of precipitating factors before each dose 2

CYP2D6 inhibitors: Meclizine is metabolized by CYP2D6, creating potential for significant drug-drug interactions that may increase meclizine levels and adverse effects 1, 3

Not recommended: Vestibular suppressant medications including meclizine should not routinely treat BPPV, as they provide no definitive benefit and may decrease diagnostic sensitivity during Dix-Hallpike maneuvers 4
Exception: Short-term use only for severe nausea/vomiting in highly symptomatic patients refusing repositioning maneuvers 4

Not appropriate: Meclizine should never be prescribed for sleep in children, as melatonin is the safer, evidence-based first-line pharmacological option after behavioral interventions 5
Cognitive impairment risk: First-generation antihistamines cause sedative effects impairing cognitive function and performance, with drivers being 1.5 times more likely to be involved in fatal accidents 5

Assuming all antihistamines are equivalent: Second-generation antihistamines (fexofenadine, loratadine, desloratadine) are strongly preferred over meclizine in older adults due to reduced sedation and anticholinergic effects 2
Overlooking medication review: In elderly patients with dementia or frailty, systematic deprescribing using STOPP/START or Beers criteria is critical, as psychotropic medications carry an odds ratio of 1.7 for falls 2
Ignoring hepatic status: Failing to assess for cirrhosis and encephalopathy risk before prescribing meclizine can lead to life-threatening complications 2
Polypharmacy interactions: Not screening for concurrent CYP2D6 inhibitors or other CNS depressants increases adverse event risk 1