Cost and benefit of secondary prophylaxis for Pneumocystis carinii pneumonia

To determine the relative cost and benefit of aerosolized pentamidine and the combination product of sulfamethoxazole and trimethoprim sulfate as secondary prophylaxis for Pneumocystis carinii pneumonia.

A Markov-based cost-benefit analysis was performed. Drug efficacies, toxicities, and mortality rates were drawn from the current literature.

Hypothetical.

Patients infected with the human immunodeficiency virus who had had at least one episode of P carinii pneumonia.

Regimen 1 required the use of aerosolized pentamidine as the sole first-line prophylactic agent in all patients. Regimen 2 required the use of sulfamethoxazole-trimethoprim in all patients who had no history of a toxic reaction to the drug; only patients with a history of toxic effects and those who developed toxic effects while receiving the drug would receive aerosolized pentamidine. Regimen 3 required that no secondary prophylaxis be given.

Net cost, median patient survival, and 5-year survival for each regimen and for regimens 1 and 2 compared with regimen 3.

Regimen 2 was dominant, with a net cost of $6332 per patient and a median survival of 2.050 years. Compared with no prophylaxis, regimen 2 resulted in a savings of $16,503 per patient and a 0.696-year increase in median survival. Compared with regimen 1, regimen 2 resulted in a savings of $2904 and a 0.067-year increase in median survival.

Secondary prophylaxis for P carinii saves money and extends survival. Current data suggest that sulfamethoxazole-trimethoprim should be given whenever it can be tolerated. Use of aerosolized pentamidine as a first-line agent would result in a modest increase in cost and a decrease in life expectancy.