D. Schurmann et al., Twice-weekly pyrimethamine-sulfadoxine effectively prevents Pneumocystis carinii pneumonia relapse and toxoplasmic encephalitis in patients with AIDS, J INFECTION, 42(1), 2001, pp. 8-15
Objective: To evaluate the safety and efficacy of a fixed 25 mg pyrimethami
ne-500 mg sulfadoxine combination plus 15 mg folinic acid given twice weekl
y for the prevention of relapses of Pneumocystis carinii pneumonia (PCP) an
d primary episodes of toxoplasmic encephalitis.
Methods: Ninety-five HIV-infected patients with successfully treated PCP an
d without history of toxoplasmic encephalitis were enrolled between January
1990 and October 1995 in a single-arm open-label prospective study. No pat
ient was receiving highly active antiretroviral treatment, including protea
se inhibitors or non-nucleoside reverse transcriptase inhibitors, while on
study medication. Efficacy was analysed on an "as-treated" basis.
Results: Five patients (5.3%) suffered a PCP relapse while on study medicat
ion, three of whom had been non-compliant. No relapse occurred in the first
year. Probabilities of freedom from relapse were 0.96 after 24 months and
0.90 after 36 months. Of 69 patients positive for anti-toxoplasma IgG antib
odies, one (1.5%) developed cerebral lesions compatible with toxoplasmic en
cephalitis after 50 months. Cutaneous allergic reactions were observed in 1
6 patients (16.8%) resulting in permanent discontinuation in six patients (
6.3%). Two patients (2.1%) developed serious adverse reactions (Stevens-Joh
nson syndrome), both of whom had continued prophylaxis despite progressive
hypersensitivity reactions.
Conclusions: The prophylactic regimen used is effective in preventing PCP r
elapses and toxoplasmic encephalitis. The regimen appears to be safe. Sever
e adverse events can likely be prevented by discontinuation of prophylaxis
at the time allergic reactions are noted. Rechallenge frequently results in
tolerance of the regimen. Efficacy and safety compare favourably with prev
iously studied regimens. This simple prophylactic regimen may provide a con
venient alternative for patients unable to tolerate approved regimens. (C)
2001 The British Infection Society.