Valproic Acid Prescribing Guidelines
1. All patients must have the following work up prior to commencement: AST + ALTs, Pregnancy test in female patients.
2. You may prescribe at 15mg/kg (dosage equivalent to 20mg/kg of Valproate) or 25mg/kg (dosage equivalent to 30mg/kg of Valproate). Please note there are 150mg, 300mg and 500mg preparations available.
3. It is best advised to start low and go slow as most side effects are dose related.
4. Titrate up to clinical response. Alternatively, one can increase the dose at a rate of every 2-4 days
5. Maximum daily dose is 2.5g/24hours
6. Regular AST+ALT are recommended. This must be done prior to commencement, at 6months and thereafter annually.
7. All female patients must be on contraceptives. There is little evidence of interaction with oral contraceptives so OCC’s may be used.
8. One must be aware of risks of hyperammonia and ketonuria secondary to Valproic Acid. Ketonuria secondary to Valproic Acid must be distinguished from diabetic ketonuria.
9. GIT side effects (such as nausea) may be minimized by giving medication with meals.
10. Please see table below for equivalent doses for further guidance as needed.