sulfamethoxazole / trimethoprim - Bactrim, Septra, or generic

Sulfamethoxazole/trimethoprim works by inhibiting the production of bacterial proteins.  Sulfamethoxazole/trimethoprim is used for a variety of purposes including but not limited to the following:

1.  Treat pneumonia including pneumocystis pneumonia (PCP,) urinary tract infections, bone infections, brain infections, skin infections, and many other serious infections
2.  Prevent pneumocystis pneumonia (this is probably one of the most common uses in the setting of HIV infection)

The usual dose to prevent pneumocystis pneumonia is one double strength tablet daily, every other day, or 3-4 days per week. 

Sulfamethoxazole/trimethoprim is used to prevent PCP in persons who have T-cell counts less than 200 or other AIDS -defining conditions.  Sulfamethoxazole/trimethoprim is usually continued until the immune system has improved dramatically with T-cell counts greater than 250 or so assuming the HIV viral load is suppressed.

For further information and tips on adherence, go to the Adherence section of this site.

It is very important to take every dose that is prescribed unless instructed by your healthcare provider.

If you miss doses, the infection that is being treated may not get better or sometimes the infection can even get much worse by the germ developing resistance to sulfamethoxazole/trimethoprim. 

If you miss doses when sulfamethoxazole/trimethoprim is used to prevent PCP, you may get PCP which is a serious, potentially life-threatening pneumonia.

It is strongly recommended that you consider using weekly pill boxes and arrange all of your doses a week in advance.  Buy a small pill box so that you can carry a dose or two of your medicines with you in case you are away from home.

Most people take sulfamethoxazole/trimethoprim without any or very many side effects. 

Possible side effects include diarrhea, nausea, kidney problems, liver problems, low white blood cells, low platelet cells, or allergic rashes.  You may be more susceptible to low white blood cells or low platelet cells if you have more advanced HIV or if you are taking other drugs that cause these side effects (zidovudine, chemotherapy, etc.) or if you have underlying conditions that cause these problems (e.g., cirrhosis).  You may be more susceptible to kidney problems if you already have some kidney problems or you are taking other drugs which can lower kidney function (aspirin, ibuprofen, furosemide, certain blood pressure medications, Alleve, Motrin, Vioxx, etc.)

Allergic rashes can be very minor to very serious (rarely,) but all rashes should be reported.  If you have rash that steadily gets worse or you have a rash and fever, you need to inform your healthcare provider immediately.

Sometimes if you are allergic to sulfamethoxazole/trimethoprim but you really need it for treatment or prevention, you may undergo a procedure called "desensitization" which may help.