Dose-escalation, phase I/II study of azithromycin and pyrimethamine for the treatment of toxoplasmic encephalitis in AIDS.
OBJECTIVE
To assess the safety, tolerance and activity of increasing doses of azithromycin in combination with pyrimethamine for the treatment of toxoplasmic encephalitis (TE) in patients with AIDS.


METHODS
A phase I/II dose-escalation study of oral azithromycin in combination with pyrimethamine.


METHODS
Eight clinical sites in the United States.


METHODS
Forty-two adult HIV-infected patients with confirmed or presumed acute TE.


METHODS
Patients were enrolled into three successive cohorts receiving azithromycin 900, 1200 and 1500 mg a day with pyrimethamine as induction therapy. The induction period was 6 weeks followed by 24 weeks of maintenance therapy.


METHODS
Patient response was evaluated clinically and radiologically.


RESULTS
Of the 30 evaluable patients, 20 (67%) responded to therapy during the induction period. Ten experienced disease progression. Of the 15 patients who received maintenance therapy, seven (47%) relapsed. Six patients discontinued treatment during the induction period as a result of reversible toxicities. Treatment-terminating adverse events occurred most frequently among the patients receiving the 1500 mg dose.


CONCLUSIONS
The combination of azithromycin (900-1200 mg a day) and pyrimethamine may be useful as an alternative therapy for TE among patients intolerant of sulfonamides and clindamycin, but maintenance therapy with this combination was associated with a high relapse rate. The combination was safe, but low-grade adverse events were common.
Jacobson
J M
JM
Department of Medicine, Mt Sinai Medical Center, New York, NY 10029, USA.
Hafner
R
R
Remington
J
J
Farthing
C
C
Holden-Wiltse
J
J
Bosler
E M
EM
Harris
C
C
Jayaweera
D T
DT
Roque
C
C
Luft
B J
BJ
D017088:AIDS-Related Opportunistic Infections / Q000000981:diagnostic imaging / Q000188:drug therapy*; D000328:Adult; D000818:Animals; D000900:Anti-Bacterial Agents / Q000009:adverse effects / Q000627:therapeutic use*; D000981:Antiprotozoal Agents / Q000009:adverse effects / Q000627:therapeutic use*; D017963:Azithromycin / Q000009:adverse effects / Q000627:therapeutic use*; D015331:Cohort Studies; D004305:Dose-Response Relationship, Drug; D004359:Drug Therapy, Combination; D004660:Encephalitis / Q000000981:diagnostic imaging / Q000188:drug therapy*; D005260:Female; D006801:Humans; D008297:Male; D011739:Pyrimethamine / Q000009:adverse effects / Q000627:therapeutic use*; D011859:Radiography; D014122:Toxoplasma; D014123:Toxoplasmosis / Q000000981:diagnostic imaging / Q000188:drug therapy*; D016896:Treatment Outcome; D014481:United States
D000900:Anti-Bacterial Agents; D000981:Antiprotozoal Agents; D017963:Azithromycin; D011739:Pyrimethamine