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.
Department of Pharmacology, University of the Western Cape, Bellville.
P
P
Valodia
M A
MA
Seymour
B M
BM
Kies
P I
PI
Folb
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