Azithromycin versus azithromycin-pyrimethamine and sulfadiazine-pyrimethamine for the treatment of ocular toxoplasmosis: a retrospective comparative case-series.

OBJECTIVES

To compare azithromycin to azithromycin-pyrimethamine and sulfadiazine-pyrimethamine for the treatment of toxoplasma-related retinochoroiditis (TRC).

SUBJECTS/

METHODS

Retrospective comparative case-series of consecutive patients treated for TRC in one tertiary centre. They were included if they had received azithromycin (A), azithromycin-pyrimethamine (AP) or sulfadiazine-pyrimethamine (SP) alongside systemic glucocorticoids; and excluded if any other treatment was given, or if no systemic glucocorticoids were used. Total sample was 493 people (SP: 267, A: 139, AP: 87). Time-to-event analysis (TTE) and logistic linear regression models were used (one eye/person).

MAIN OUTCOME MEASURE: Drop in BCVA of more than 0.2 LogMAR within six months. Further outcome measures: Disease recurrence within one year; disease inactivation within six weeks; number of people with treatment switch and adverse events.

RESULTS

There was no significant difference between the groups in probability of visual loss (including subgroup analysis for macular lesions), disease recurrence within one year, and disease inactivity within six weeks. The total number of treatment switches was not significantly different between groups (SP: 39/238 [16%]; A: 13/131 [10%], OR = 0.51; AP: 14/80 [18%], OR = 1.03; sample for this analysis: 449 people), although the most common switch reason varied (A: poor response; AP and SP: adverse event). There were more adverse events in both combination groups than azithromycin (A: 6/131 [5%]; SP: 66/238 [28%], OR = 7.9, p value < 0.001; AP: 16/80 [20%], OR = 5.2, p value = 0.001).

CONCLUSION

Azithromycin had similar outcomes to azithromycin-pyrimethamine and sulfadiazine-pyrimethamine for the treatment of TRC, whilst having a better tolerance.