Long-term efficacy and safety of efavirenz dose reduction to 200 mg once daily in a Caucasian patient with HIV.
Clin Drug Investig
; 30(6): 405-11, 2010.
Article
en En
| MEDLINE
| ID: mdl-20441246
ABSTRACT
A 48-year-old Caucasian male patient presented with severe adverse drug events (ADEs) while being treated with a standard dose (600 mg/day) of efavirenz. The patient's clinical course was favourable; however, he also described intense nightmares, cramps in his legs and anxiety disturbances that made him highly irritable. Measurement of the patient's efavirenz plasma concentrations revealed a mean minimum steady-state concentration during a dosage interval (C(min,ss)) of 12.7 mg/L, which was much higher than that recommended for this drug (therapeutic range 1-4 mg/L). Consequently, the dose of efavirenz was reduced to 400 mg/day, which resulted in a decrease in the frequency of ADEs. Subsequent genotype testing showed that the patient was homozygous for both the CYP2B6-G516T (T/T) and CYP2B6-A785G (G/G) alleles; these polymorphisms are associated with reduced enzymatic activity and elevated efavirenz plasma concentrations. Because of this and the fact that the patient's mean efavirenz C(min,ss) was still high (4.6 mg/L), a second dosage reduction was undertaken, to 200 mg/day. This also resulted in a reduction in ADEs. At present, the patient's CD4+ levels remain stable, his viral load continues to be undetectable and the mean efavirenz C(min,ss) is within the therapeutic range (2.7 mg/L).
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Infecciones por VIH
/
Fármacos Anti-VIH
/
Benzoxazinas
Tipo de estudio:
Observational_studies
/
Prognostic_studies
/
Risk_factors_studies
Límite:
Humans
/
Male
/
Middle aged
Idioma:
En
Revista:
Clin Drug Investig
Asunto de la revista:
FARMACOLOGIA
/
TERAPIA POR MEDICAMENTOS
Año:
2010
Tipo del documento:
Article
País de afiliación:
España