Clonazepam Contraindications
Clonazepam is absolutely contraindicated in patients with a history of benzodiazepine sensitivity, significant liver disease, and acute narrow-angle glaucoma 1.
Absolute Contraindications
According to FDA labeling, clonazepam must not be used in the following conditions 1:
- Benzodiazepine hypersensitivity: Any history of allergic or sensitivity reactions to benzodiazepines
- Significant hepatic disease: Clinical or biochemical evidence of substantial liver impairment
- Acute narrow-angle glaucoma: This is an absolute contraindication; however, clonazepam may be used in patients with open-angle glaucoma who are receiving appropriate therapy
Critical Clinical Considerations
High-Risk Populations Requiring Extreme Caution
While not absolute contraindications, the following conditions warrant serious consideration before prescribing clonazepam, as they significantly impact morbidity and mortality:
Respiratory compromise 1:
- Clonazepam causes respiratory depression
- Use extreme caution in COPD, sleep apnea, or any compromised respiratory function
- This becomes particularly dangerous when combined with opioids, which can be fatal
Severe renal impairment 1:
- Clonazepam metabolites are renally excreted
- Accumulation can lead to toxicity in patients with kidney dysfunction
Elderly patients 2:
- Listed on the American Geriatrics Society Beers Criteria as potentially inappropriate
- Higher risk of falls, cognitive impairment, delirium, and amnesia
- Age-related changes in drug metabolism increase sensitivity over time
Important Safety Warnings
Sleep-disordered breathing 2:
- Clonazepam can exacerbate sleep-disordered breathing
- This is particularly problematic in patients with REM sleep behavior disorder who may have underlying neurodegenerative disease
Acute angle-closure glaucoma risk 3:
- New users of benzodiazepines, including clonazepam, have significantly increased risk of developing acute angle-closure glaucoma
- Risk is highest within the first 7 days of use (aOR = 3.09)
- Monitor for visual disturbances, especially during initial prescription period
Porphyria 1:
- Clonazepam may have porphyrogenic effects
- Use with care in patients with this condition