Table 2.
Description of randomized controlled trials involving anti-epileptic drugs
| Source | Drugs studied | Population (setting) |
Study Design | Number of patients (age mean or range)/ Duration |
Jadad score* | Results | Conclusion | Listed source of funding |
|---|---|---|---|---|---|---|---|---|
| Hodges et al., 1986 | Dilantin (Parke-Davis) vs. 2 versions of phenytoin (Boots and Evans) | Newly diagnosed children with epilepsy (UK) | Randomized double-blind crossover trial | 19 (9.5 yrs)/12 wks (three 4-wk arms) | 2 | Dilantin: 43 seizures; phenytoin (Boots): 30 seizures; phenytoin (Evans): 60 seizures (not statistically significant) | One generic with plasma concentration differences, but no correlation with seizure outcomes | Brand-name mfr (Parke-Davis) |
| Kishore et al., 1986 | Dilantin (Parke-Davis) vs. epsolin (Cadila), eptoin (Boots), epileptin (Indian Drugs and Pharmaceuticals) | Newly diagnosed patients with epilepsy (India) | Randomized controlled trial | 60 (30.3 yrs)/3 mos | 2 | 4 uncontrolled patients in Dilantin group and 2 uncontrolled patients in each generic group (p>0.05) | No significant difference in clinical effects | Not listed |
| Jumao-as et al., 1989 | Tegretol (Geigy) vs. carbamazepine (Parke-Davis) | Epileptic patients uncontrolled on current med regimen, which included carbamazepine (US) | Randomized double-blind crossover trial | 10 (34–70 yrs)/10 wks (5 wks per arm) | 4 | 6 (out of 10) patients had seizures on brand and 6 (out of 10) had seizures on generic | No significant difference in mean seizure frequency | Medical center and government |
| Hartley et al., 1991 | Tegretol (Ciba-Geigy) vs. carbamazepine (Ethical Generics) | Children with history of epilepsy (10 stable on Tegretol, 13 new patients) (UK) | Randomized double-blind crossover trial | 23 (10.7)/12 wks (6 wks per arm) | 3 | 8 patients had seizures on brand and 8 patients had seizures on generic (p>0.32) | No significant difference in seizure frequency | Not listed (brand-name mfr [Ciba-Geigy] paid for lab measurements) |
| Soryal et al., 1992 | 2 versions of Dilantin (Parke-Davis) vs. 5 versions of phenytoin (Evans, APS, A H Cox, Thomas, Regent) | Epileptic patients on maintenance phenytoin (UK) | Randomized single-blind crossover trial | 14 (18–67)/28 wks (seven 4-wk arms) | 2 | No statistically significant difference when comparing incidence of seizure frequency | Plasma concentration differences, but no clinical differences | Not listed |
| Wolf et al., 1992 | 2 established versions of sustained-release carbamazepine vs. new sustained-release version (Sanofi Winthrop) | Epileptic patients stably treated on sustained-release carbamazepine monotherapy (Germany) | Randomized single-blind crossover trial | 10 (26)/9 days (three 3-day arms) | 2 | 3 patients with seizures on established brand #1, 3 on established brand #2, and 2 on the new version. | No indication of differences in therapeutic efficacy apart from 1 severely toxic patient | Sanofi Winthrop (mfr) |
| Oles et al., 1992 | Tegretol (Ciba-Geigy) vs. epitol (Lemmon) | 2 cohorts of epileptic patients: (1) stable on carbamazepine montherapy and (2) refractory (US) | Randomized double-blind crossover trial | (1) 15 (32); (2) 18 (40)/180 d (90 d per arm) | 4 | (1) 4/20 seizures on Tegretol vs. 2/20 seizures on epitol; (2) Avg seizure frequency 0.22 on Tegretol vs. Avg seizure frequency 0.25 on epitol (statistically similar, p=0.002) | Two drugs performed equally well in clinical efficacy | Lemmon (mfr) |
| Silpakit et al., 1997 | Tegretol (Ciba-Geigy) vs. carmapine [G1] (Central-poly), carzepine [G2] (Condrugs), panital [G3] Pharmaland) | Epileptic patients on stable dose of Tegretol (Thailand) | Randomized three-phase crossover trial | 18 (32.9)/12 wks (4 three-wk arms) | 4 | 2 patients had seizures on G1, 7 patients on G2, 3 patients on G3, 5 on brand Tegretol (p=0.08) | No significant difference in seizure frequency among brands | Hospital fund |
| Vadney et al., 1997 | Depakene (Abbott) vs. valproic acid [VPA] (Solvay) | Institutionalized patients stable on Depakene or VPA for seizures (US) | Randomized receiver-blinded crossover trial | 64 (39.6)/8 wks (4 wks per arm) | 2 | Mean number of seizures 50.89 for Depakene vs. 49.83 for VPA (p=0.89) | No significant differences in seizure control | Government |
*
Jadad score ranges 1–5, with 5 indicating highest quality.29