From the Research
When converting from lorazepam (Ativan) to clobazam, use an approximate equivalence ratio of 1 mg lorazepam to 10-20 mg clobazam. For example, a patient taking 2 mg of lorazepam daily would typically be converted to approximately 20-40 mg of clobazam daily. The conversion should be individualized and implemented gradually, often starting at the lower end of the equivalent dose range and titrating up as needed. Begin with a divided dose of clobazam (typically twice daily) while simultaneously tapering the lorazepam over 1-2 weeks to minimize withdrawal symptoms. Monitor the patient closely during this transition for signs of over-sedation or breakthrough anxiety/seizures. This conversion ratio reflects the differences in potency between these benzodiazepines, with lorazepam being more potent on a milligram basis than clobazam. Clobazam has a longer half-life (36-42 hours) compared to lorazepam (10-20 hours), which may provide more stable blood levels and potentially fewer withdrawal symptoms between doses. Elderly patients or those with hepatic impairment may require lower initial doses and more gradual titration due to altered drug metabolism 1.
Some key points to consider during the conversion process include:
- The pharmacokinetics of clobazam and its active metabolite, N-desmethylclobazam, which are metabolized in the liver via the cytochrome P450 pathway 2
- The potential for drug-drug interactions, particularly with drugs metabolized by CYP2D6, which may require dosage adjustment 2
- The importance of individualizing the conversion process and monitoring the patient closely for signs of over-sedation or breakthrough anxiety/seizures
- The need for gradual titration, especially in elderly patients or those with hepatic impairment, to minimize the risk of adverse effects
It is also worth noting that clobazam has been shown to have a more favorable side effect profile compared to other benzodiazepines, with less sedation and fewer cognitive impairments 3, 4. However, the conversion process should still be approached with caution and careful monitoring to ensure the best possible outcome for the patient.