The mechanism seems to vary with different organisms and is not well understood. However, pentamidine is suspected to work through various methods of interference of critical functions in DNA, RNA, phospholipid and protein synthesis. Pentamidine binds to adenine-thymine-rich regions of the Trypanosoma parasite DNA, forming a cross-link between two adenines four to five base pairs apart. The drug also inhibits topoisomerase enzymes in the mitochondria of Pneumocystis jirovecii. Similarly, pentamidine inhibits type II topoisomerase in the mitochondria of the Trypanosoma parasite, resulting in breaks and unraveling its circular mitochondrial DNA.
On rare occasions, pneumocystis infections have occurred in parts of the body outside the lungs in patients receiving pentamidine inhalation therapy. You should discuss this possible problem with your doctor.
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
Other side effects not listed may also occur in
some patients. If you notice any other effects, check with your healthcare
Pentamidine is given either as an injection, or as in inhaled medicine using a nebulizer. Follow all directions on your prescription label. Do not use this medicine in larger or smaller amounts or for longer than recommended.
Pentamidine is a powder medicine that must be mixed with a liquid (diluent) before using it as an injection or with a nebulizer. If you are using this medicine at home, be sure you understand how to properly mix and store the medicine. Use only the diluent provided with your medication.
To use pentamidine as an injection:
To use pentamidine with a nebulizer:
If you are diabetic, check your blood sugar carefully while you are receiving pentamidine. This medicine can raise or lower your blood sugar.
While using pentamidine, you may need frequent blood tests. Your heart function may need to be checked using an electrocardiograph or ECG (sometimes called an EKG).
Store unmixed medicine at room temperature away from moisture, heat, and light.
Mixed medicine must be used within a certain number
of hours, depending on the diluent. Carefully follow the mixing and
storage instructions provided with your medicine. Ask your pharmacist if you
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.
Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Certain medicines should
not be used at or around the time of eating food or eating certain types of
food since interactions may occur. Using alcohol or tobacco with certain
medicines may also cause interactions to occur. Discuss with your healthcare
professional the use of your medicine with food, alcohol, or tobacco.
To help prevent the development or return of pneumocystis pneumonia, you must receive pentamidine inhalation on a regular basis, even if you are feeling well.