Pentamidine gastrointestinal effects

In an uncontrolled study in French Guiana, intramuscular pentamidine isethionate (two 4 mg/kg injections 48 hours apart) in 198 patients with cutaneous leishmaniasis produced a cure rate of 87% 80% of treatment failures responded to an identical second course (1). Compared with published studies, adverse events were relatively mild pain on injection (54%), gastrointestinal effects (53%), and hypotension (8%). There were no dysrhythmias or glucose abnormalities. This may reflect the brief course of pentamidine used. 

It is used in the treatment of pneumocystosis (pulmonary and extrapulmonary disease caused by P. carinii), African trypanosomiasis (disease caused by Trypanosoma brucei) and leishmaniasis. Systemic pentamidine is highly toxic and can lead to severe hypotension, tachycardia, dyspnea, dizziness, hypoglycemia. Other adverse effects are skin rash, metallic taste, gastrointestinal symptoms, thrombocytopenia and cardiac arrhythmias. 

Adverse Effects. The primary adverse effect of systemic pentamidine administration is renal toxicity. Renal function may be markedly impaired in some patients, but kidney function usually returns to normal when the drug is withdrawn. Other adverse effects include hypotension, hypoglycemia, gastrointestinal distress, blood dyscrasias (leukopenia, thrombocytopenia), and local pain and tenderness at the site of injection. Adverse effects are reduced substantially when the drug is given by inhalation, and this method of administration is desirable when pentamidine is used to prevent pneumocystis pneumonia in patients with human immunodeficiency virus (HIV) disease. 

Pancreatic toxicity is common. Hypoglycemia due to inappropriate insulin release often appears 5-7 days after onset of treatment, can persist for days to several weeks, and may be followed by hyperglycemia. Reversible renal insufficiency is also common. Other adverse effects include rash, metallic taste, fever, gastrointestinal symptoms, abnormal liver function tests, acute pancreatitis, hypocalcemia, thrombocytopenia, hallucinations, and cardiac arrhythmias. Inhaled pentamidine is generally well-tolerated but may cause cough, dyspnea, and bronchospasm. 

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