Table 5.
Trial | Adverse event data1 | Summary of reported results | |
Phenytoin (PHT) | SV (Sodium Valproate) | ||
Callaghan 1985 | All adverse events developed (by drug) and adverse events leading to discontinuation of treatment | PHT (n = 58): gum hypertrophy (n = 2), rash (n = 2), ataxia (n = 2) |
SV (n = 64): weight gain (n = 4 – all discontinued treatment), drowsiness (n = 2), aggressive behaviour (n = 1 – discontinued treatment) |
Craig 1994 | Adverse event frequency (spontaneous reports)2 Discontinuations due to adverse events3 |
PHT (n = 25): unsteadiness (n = 9), sleepiness (n = 7), drowsiness (n = 2), impaired concentration (n = 2), confusion (n = 1), constipation (n = 1), diarrhoea (n = 1), dysarthria (n = 1), lethargy (n = 1), nystagmus (n = 1), rash (n = 1), tired legs (n = 1) PHT discontinuations (n = 6): rash (n =1), diarrhoea (n = 1), confusion (n = 1), unsteadiness (n = 1), constipation (n = 1), sleepiness (n = 1) |
SV (n = 17): unsteadiness (n = 2), sleepiness (n = 3), tremor (n = 5), oedema (n = 3), alopecia (n = 2), depression (n = 2), weight gain (n = 2) SV discontinuations (n = 2): weight gain and depression (n = 1), unsteadiness (n =1) |
Czapinski 1997a | “Exclusions” due to adverse events or no efficacy4 | Proportion “excluded”: PHT: 33.3% | Proportion “excluded”: SV: 23.3% |
De Silva 1996 | “Unacceptable” adverse events leading to drug withdrawal5 | PHT (n = 54): drowsiness (n = 2), skin rash (n = 1) blood dyscrasia (n = 1), hirsutism (n = 1) | SV (n = 49): behavioural (n = 1), tremor (n = 1) |
Forsythe 1991 | No adverse event data reported (Withdrawal data only reported) |
1 participant (PHT) withdrew from the study due to depression and anorexia | No adverse event data (or withdrawals due to adverse events) reported |
Heller 1995 | “Unacceptable” adverse events leading to drug withdrawal5 | PHT (n = 63): myalgia (n = 1), irritability (n = 1) |
SV (n = 61): dizziness (n = 2) abnormal liver function test (n = 1) |
Ramsay 1992 | Most common adverse events (by treatment group)6 | PHT (n = 50): dyspepsia (n = 1), nausea (n = 2), dizziness (n = 2), somnolence (n = 5), tremor (n = 2), rash (n = 4) |
SV (n = 86): dyspepsia (n = 7), nausea (n = 10), dizziness (n = 5), somnolence (n = 8), tremor (n = 5), rash (n = 3) |
Rastogi 1991 | Commonest adverse events (reported as percentages by treatment group)6 | PHT (n = 45): gum hyperplasia (17.7%), nystagmus (13.33%), ataxia (2.2%), gastrointestinal disturbances (4.44%), drowsiness (4.44%) | SV (n = 49): gastrointestinal disturbances (12%), drowsiness (6.12%), weight gain (2.04%) |
Shakir 1981 | Adverse events (narrative description)2 | PHT (n = 15): 1 case of ataxia, 5 cases of acne | SV (n = 18): 2 cases of gastrointestinal symptoms, 2 cases of hair loss, 4 cases of weight gain |
Thilothammal 1996 | Assessment of adverse events2 | PHT (n = 52): 33 participants reported at least one side effect Reported frequencies: gingival hypertrophy (n = 30), ataxia (n = 13), sedation (n = 12), nausea and vomiting (n = 1) Other reported adverse events (no frequencies): nystagmus, confusion |
SV (n = 48): 15 participants reported at least one side effect Reported frequencies: hyperactivity (n = 6), impaired school performance (n = 4), severe skin allergy (n = 1) |
Turnbull 1985 | Withdrawals due to dose‐related and idiosyncratic adverse events | PHT (n = 70): 11 withdrawals due to dose‐related adverse events (nystagmus, ataxia, tremor, diplopia and mental change) 5 withdrawals due to idiosyncratic adverse events (skin eruption, erythroderma and jaundice) |
SV (n = 70): 9 withdrawals due to dose‐related adverse events (tremor, irritability, restlessness and alopecia) No withdrawals due to idiosyncratic adverse events |
1Adverse event data, as reported narratively in the publications. Adverse event data were not requested in original IPD requests but will be for all future IPD requests. For numbers of withdrawals due to adverse events in studies for which IPD were provided (De Silva 1996; Heller 1995; Ramsay 1992; Turnbull 1985) see Table 6. 2Participants may report more than one adverse event. 3The published paper, Craig 1994, reports on a subset of 38 participants, so the adverse event data summary applies only to this subset. IPD were provided for 166 participants (no additional adverse event data provided). 4Czapinski 1997a is an abstract only so very little information is reported. 5Participants may have withdrawn due to adverse event alone or a combination of adverse events and poor efficacy (seizures). 6Most commonly reported adverse events only, no indication of overall frequency of all adverse events.