Cinnarizine Adverse Effects
Cinnarizine commonly causes neurological side effects including drowsiness, extrapyramidal symptoms, and rarely seizures, particularly in overdose or pediatric patients. 1
Neurological Adverse Effects
- Drowsiness/somnolence is the most frequently reported side effect of cinnarizine 2, 3
- Extrapyramidal symptoms can occur, particularly in elderly patients, due to cinnarizine's antagonistic properties at dopamine D2 receptors 4
- Dizziness and vertigo may paradoxically occur during treatment 2
- Jitteriness, wide-based gait, and stupor have been reported in overdose cases 1
- Seizures have been documented in pediatric overdose cases, likely related to cinnarizine's antihistaminic and antidopaminergic effects 1
Gastrointestinal Adverse Effects
- Nausea and vomiting are common side effects 1, 2
- Abdominal pain has been reported in some patients 2
- Epigastralgia (stomach pain) can occur during treatment 5
Other Adverse Effects
- Weight gain has been reported as a side effect in some patients 5
- Headache can occur in some patients taking cinnarizine 2
- Cinnarizine has calcium channel-blocking properties, though adverse effects related to this mechanism (such as bradycardia or hemodynamic instability) are rarely observed even in overdose 1
Special Populations and Considerations
- Pediatric patients are particularly susceptible to neurological complications in overdose scenarios 1
- Elderly patients are at higher risk for developing drug-induced parkinsonism and other extrapyramidal symptoms due to cinnarizine's D2 receptor antagonism 4
- In cases of overdose, symptoms may be delayed in onset, with clinical effects appearing several hours after ingestion 1
Monitoring and Management
- Patients experiencing severe vertigo as a side effect should discontinue the medication 5
- Pediatric patients with cinnarizine overdose require observation in a healthcare facility for potential neurological complications 1
- The half-life of cinnarizine is approximately 3.65 hours based on toxicokinetic data 1
- Most side effects are transient and resolve with dose reduction or discontinuation of the medication 2, 5