Alternative regimens, which are also given for 21 days, are Pentamidine 4 mg / kg IV once a day Atovaquone 750 mg orally 2 times a day Trimethoprim 5 mg / kg orally 3times a day with dapsone 100 mg orally once a day Clindamycin 900 mg IV every 8 hours, 600 mg IV every 6 hours, 600 mg orally 3 times a day, or 450 mg orally 4 times a day, plus primaquine base 30 mg orally once a day The major limitation of pentamidine is the high frequency of toxic adverse effects, including acute kidney injury, hypotension, and hypoglycemia.