Atovaquone for the treatment of toxoplasma retinochoroiditis in immunocompetent patients

Objective: To report the results of a phase I trial to evaluate the safety and efficacy of atovaquone for the treatment of ocular toxoplasmosis in imm unocompetent patients. Design: Open label, nonrandomized, prospective, clinical trial. Participants: Seventeen immunocompetent patients between the ages of 18 and 75 years with clinical and serologic evidence of ocular toxoplasmosis part icipated. Intervention: Treatment of ocular toxoplasmosis with atovaquone tablets (75 0 mg four times a day) for 3 months. Prednisone (40 mg) tablets were added on day 3 of treatment and tapered as inflammation resolved. Main Outcome Measures: Clinical response and patient tolerance to atovaquon e therapy for ocular toxoplasmosis, Results: Average follow-up was 10 months, Most patients experienced no adve rse treatment effects. When present, side effects were usually mild and inc luded rash, pruritus, headache, and nausea. With the exception of one patie nt, who discontinued treatment at 6 weeks secondary to persistent epigastri c discomfort, all patients completed the 12 weeks of therapy. All patients had a favorable response to treatment that began within 1 to 3 weeks. Visua l acuity was stabilized or improved in all patients. Median initial visual acuity was 20/200 and median final visual acuity was 20/25, In general, ato vaquone was well tolerated. Conclusions: Atovaquone is better tolerated than conventional antitoxoplasm osis therapy and appears to be at least as effective. Atovaquone is a promi sing alternative for the treatment of ocular toxoplasmosis in immunocompete nt patients.