Benefits of a clinical pharmacokinetic service in optimising phenytoin use in the western Cape.
OBJECTIVE
To study the benefits of a clinical pharmacokinetic service in optimising phenytoin use in the Western Cape.


METHODS
Assessment of the response to treatment was based on the number of seizures during the 3 months before entering the study (first baseline period), 3 months after entering the study (second baseline period) and 3 months before the termination of the study (test period). Patients kept a seizure diary throughout the study. The Michaelis-Menten model was used to calculate doses and predict steady-state serum concentrations.


METHODS
Nine epilepsy clinics.


METHODS
One hundred and ninety-five (113 black and 82 coloured) compliant people with epilepsy receiving generic phenytoin monotherapy.


METHODS
Reduction in seizure frequency and adverse effects.


RESULTS
A reduction in seizure frequency (64.8% compared with pre-optimisation) was experienced by 64.9% of patients. Mean seizure frequency was reduced from 3.39 to 1.18 per month. Reductions in seizure frequency of 100% and more than 50% were reported by 39.2% and 58.7% of patients, respectively. Adverse effects of phenytoin were reduced from 20.5% at the first visit to 3.2% at the last visit.


CONCLUSIONS
The clinical pharmacokinetic dosing service for phenytoin applied in this study contributed significantly to the success of epilepsy management.
Valodia
P
P
Department of Pharmacology, University of the Western Cape, Bellville.
Seymour
M A
MA
Kies
B M
BM
Folb
P I
PI
D000554:Ambulatory Care Facilities / Q000458:organization & administration*; D000927:Anticonvulsants / Q000009:adverse effects / Q000097:blood / Q000493:pharmacokinetics*; D004827:Epilepsy / Q000097:blood / Q000188:drug therapy*; D006801:Humans; D010349:Patient Compliance; D010672:Phenytoin / Q000009:adverse effects / Q000097:blood / Q000493:pharmacokinetics*; D012017:Referral and Consultation; D016896:Treatment Outcome
D000927:Anticonvulsants; D010672:Phenytoin