Safety of pentamidine prophylaxis for Pneumocystis carinii pneumonia on the endocrine pancreatic function in HIV patients.

We assessed the pancreatic beta cells function of HIV patients receiving either 300 mg per month of aerosolized pentamidine (n = 12) or oral trimethoprim-sulfamethoxazole (TMP-SMX), twice a day three times per week (TMP: 160 mg, SMX: 800 mg) (n = 10). Intravenous (i.v.) glucose tolerance tests were performed after i.v. injection of 0.5 glucose by kg of body weight in 30 seconds. Plasma insulin levels were assessed at baseline, 1, 2, 3 and 5 min. Moreover, in patients receiving inhaled pentamidine, plasma glucose amylase and insulin levels were measured every 30 min for 2 hours after the end of the aerosol. Plasma pentamidine levels were measured 30 min after the end of the aerosol. Those tests were performed every 2-3 months for one year. In most patients taking aerosol treatment, pentamidine levels were detectable, remaining under levels of 50 ng/ml. Pentamidine plasma levels increased in a time dependent manner. Baseline plasma glucose, amylase and insulin levels were in normal range and remained stable during the therapy. For 7 out of 12 patients, glucose tolerance tests showed an adequate insulin secretion: the addition of the two best insulin levels were higher than 70 IU/ml. When this criteria was not found (n = 5), a glucagon stimulation test allowed to exclude an endocrine pancreatic dysfunction. Due to its apparent short half-life, increased pentamidine levels could be related to an improvement of spray techniques as well as to a cumulative effect. Pancreatic function was preserved in pentamidine-treated patients compared to TMP-SMX-treated patients.