How soon after taking pentamidine will my symptoms improve?

Pentamidine should act quickly to start fighting the infection, particularly if you're taking it through an IV. It may take a few weeks to a few months for the drug to help your body rid itself of the illness. Whether your condition improves and how long it takes to do so will vary widely, depending on the severity of your condition and what pre-existing conditions you may have. As pneumocystis pneumonia (the primary illness treated by pentamidine) most often affects people who already have their immune systems compromised by HIV, cancer or other conditions, combating the illness may be difficult.