Therapeutic drug monitoring improves seizure control and reduces anticonvulsant side-effects in patients with refractory epilepsy.
The benefit to patients of an on-site antiepileptic drug monitoring service, in which physicians' decisions were recorded before and after the concentration became available, have been assessed retrospectively. In 109 patients with refractory epilepsy monitored on three (n = 61) or four (n = 48) occasions between 1986 and 1990, one or more assay result was rated as 'unexpected' by the consulting doctor. In 51 of these, revision of the dose was undertaken as a consequence (active group). Their clinical outcomes were compared with those of the other 54 patients in whom the initial management plan was left unchanged (passive group). Median seizure frequency decreased in both groups, but this was statistically significant only for the actively treated patients [active group: first visit 1 (0 to 26) seizures/month, last visit 0 (0 to 19) seizures/month, P < 0.01, 95% CI -2 to -0.5; passive group: first visit 2.5 (0 to 57) seizures/month, last visit 1.5 (0 to 44) seizures/month, NS, 95% CI -1 to +10]. The number of patients reporting one or more episodes of drug-related toxicity also favoured the actively managed patients (active group 25%, passive group 56%, P < 0.01). Within this selected group of patients, the anticonvulsant concentration was a better guide to clinical management than the physician's assessment.
University Department of Medicine and Therapeutics, Western Infirmary, Glasgow, UK.
P J
PJ
McKee
I
I
Percy-Robb
M J
MJ
Brodie
D000927:Anticonvulsants / Q000009:adverse effects / Q000493:pharmacokinetics* / Q000627:therapeutic use; D002220:Carbamazepine / Q000009:adverse effects / Q000493:pharmacokinetics / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D016903:Drug Monitoring; D004569:Electroencephalography / Q000187:drug effects; D004828:Epilepsies, Partial / Q000097:blood / Q000188:drug therapy; D004827:Epilepsy / Q000097:blood* / Q000188:drug therapy; D004829:Epilepsy, Generalized / Q000097:blood / Q000188:drug therapy; D005500:Follow-Up Studies; D006801:Humans; D010672:Phenytoin / Q000009:adverse effects / Q000493:pharmacokinetics / Q000627:therapeutic use; D012189:Retrospective Studies; D014635:Valproic Acid / Q000009:adverse effects / Q000493:pharmacokinetics / Q000627:therapeutic use
D000927:Anticonvulsants; D002220:Carbamazepine; D014635:Valproic Acid; D010672:Phenytoin