Doses-carga de carbamazepina e difenil-hidantoína: utilização em pacientes de alto risco

Abstract

Loading-doses of phenytoin (1000 mg) and carbamazepine (600 mg) were given orally respectively to 10 and 6 patients with uncontrolled epileptic seizures secondary to acute neurological disorders or alcohol withdrawal. In the phenytoin group age varied between 12-73 years and serum concentrations at 2, 4, 6, 8, 12 and 18 hours after drug administration were 7.6, 8.8, 8.7, 8.7, 7.2 and 6.5 micrograms/ml (means). A quantitative method did not detect important side-effects. In the carbamazepine group age varied between 25-56 years and serum concentrations at the same times were 3.9, 5.3, 6.5, 7.5, 7.4 and 8.2 micrograms/ml. Side-effects were discrete. Further medication was not necessary in the 24 hours after drug administration. Although both regimens controlled the clinical situation without relevant side-effects serum concentrations were sub-therapeutic in the case of phenytoin. We suggest the ideal phenytoin oral loading-dose is 1500 mg. The carbamazepine load produced therapeutic concentrations. The stability of serum concentrations for the period of the study shows that those regimens are useful in the subacute control of epileptic seizures in the maintenance treatment of status epilepticus and in alcohol withdrawal.

Acute Oral Loading of Carbamazepine‐CR and Phenytoin in a Double‐Blind Randomized Study of Patients at Risk of Seizures

“…Miles et al (1989) administered 8-to 10-mg/kg CBZ suspension and reported no adverse effects. Leite et al (1987) administered a 600-mg CBZ dosage with no significant side effects. Schmidt et al (1984) administered CBZ oral suspension (7.3 mg/kg) and reported side effects in 7 of 8 subjects (vertigo 6, ataxia 6, nystagmus 3, and drowsiness 5).…”

“…Studies of effective acute oral loading doses of phenytoin (PHT, Wilder et al, 1973;Gibberd and Webley, 1975;Evens et al, 1980;Bittencourt and Richens, 1985;Osborn et al, 1987;Leite et al, 1987;Galdames et al, 1988) (Table 1) and carbamazepine (CBZ, Schmidt et al, 1984;Bittencourt and Richens, 1985;Macphee et al, 1986;Leppik et al, 1988; Leite et al, 1987;Bourgeois et al, 1989;Miles et al, 1989, Van der Meyden et al, 1992) (Table 2) are sparse and incomplete.…”