The Impact of Short-Term,Intensive Antifolate Treatment (with Pyrimethamine and Sulfadoxine) and Antibiotics Followed by Long-Term,Secondary Antifolate Prophylaxis on the Rate of Toxoplasmic Retinochoroiditis Recurrence

Purpose: to assess the impact of intensive antifolate treatment,followed by secondary antifolate prophylaxis (a-sp) on the recurrence rate of toxoplasmic retinochoroiditis (trc). to investigate whether there are any other factors potentially predisposing for recurrence. material and methods: a total of 637 medical records of trc patients,who had been treated in the years 1994–2013 were reviewed. all patients were treated with pyrimethamine /sulfadoxine one 25mg/500mg tablet daily (p/s 25/500mg) for 21 days with a double loading dose for the first two days. from day 2 the patients also received prednisone at a starting dose of 40mg and spiramycine 3 million iu three times daily,given for 10 days followed by azithromycin 500mg once daily for another 6 days. the analysis of the recurrence rate involved 352 patients who had completed 6-month secondary prophylaxis (p/s one 25 mg/500mg tablet twice a week). results: when secondary antifolate prophylaxis (a-sp) was instituted immediately after the treatment for trc,the probability of 3-year recurrence–free survival after the first course of a-sp was 90.9%. a recurrence was most likely approximately 3.5 years after the first treatment. a univariate cox regression model demonstrated that a risk for recurrence was 2.82 times higher (p = 0.02) in patients with retinal scars. in the multivariate analysis,the risk for recurrence was 2.41 higher (p = 0.06). in patients with haemorrhagic lesions the risk for recurrence was lower,arr = 0.17 (approaching borderline statistical significance p = 0.08). conclusions: with the institution of a-sp of immediately after the intensive treatment for trc,i.e. when a reactivation was most likely,there was no recurrence during a-sp. following a-sp the recurrence rates were low and recurrence-free periods tended to be longer. the treatment regimen employed had a beneficial effect on the recurrence interval as it reduced and delayed the highest probability of recurrence. © 2016 borkowski et al.