What are the side effects of biperiden?

Side Effects of Biperiden

Biperiden, an anticholinergic agent used primarily to treat drug-induced extrapyramidal symptoms and Parkinson's disease, causes typical anticholinergic side effects including CNS impairment (delirium, slowed comprehension), impaired vision, urinary retention, constipation, sedation, and increased fall risk, particularly in older adults. 1

Primary Anticholinergic Side Effects

Biperiden produces the classic anticholinergic toxidrome that affects multiple organ systems:

Central Nervous System Effects

• Cognitive impairment including delirium and slowed comprehension 1
• Sedation and drowsiness 1
• Mood elevation has been documented as a notable side effect in individuals taking antipsychotic medications 2
• Temporary declines in cognitive functioning, specifically affecting sustained attention, verbal memory (2-3 fewer words recalled), and working memory (up to 50 milliseconds increase in reaction time) 3

Peripheral Anticholinergic Effects

• Visual disturbances and impaired vision 1
• Urinary retention 1
• Constipation 1
• Dry mouth (xerostomia) 1

Safety Concerns in Vulnerable Populations

Older adults are at particularly high risk for adverse effects from biperiden and other anticholinergic medications 1:

• Increased fall risk due to sedation and impaired mobility 1
• Worsened cognitive function, especially problematic in patients with underlying dementia 1
• Should generally be avoided in elderly patients per Beers Criteria principles for anticholinergic medications 1

Dosing and Tolerability

• High-dose biperiden therapy (up to 40 mg/day) has been used for dystonia treatment and was generally well tolerated in younger patients (ages 15-30 years) 4
• The medication shows high intersubject and interoccasion variability in pharmacokinetics, meaning individual responses can vary significantly 3
• Most side effects are dose-dependent and concentration-dependent 3

Clinical Context and Monitoring

The risk-benefit profile must be carefully considered, particularly when:

• Prescribing to elderly patients, where anticholinergic burden contributes to polypharmacy complications 1
• Using in patients with preexisting cognitive impairment 1
• Combining with other medications that have anticholinergic properties 1

Overdose Precautions

• Keep out of reach of children 5
• In case of overdose, contact Poison Control Center immediately 5
• Store in a cool place after opening 5