What Is SMZ-TMP?

Clara Kedrek
Clara Kedrek
SMZ-TMP can be used to treat urinary tract infections.
SMZ-TMP can be used to treat urinary tract infections.

SMZ-TMP is an abbreviation used to refer to a medication containing the active ingredients sulfamethoxazole and trimethoprim. These drugs are antibacterial agents that are given to fight infections. Often they are used together because they act in a synergistic way to decrease the ability of bacteria to create folate, a substance critical for their survival. Common uses of SMZ-TMP include the treatment of cellulitis, urinary tract infections, respiratory tract infections, and diarrhea. Side effects of the drug can include nausea, vomiting, skin rash, and abdominal pain.

The active ingredients of SMZ-TMP are effective in killing bacteria, thus allowing the human body to rid itself of harmful bacterial species causing infections. These two medications are often combined because they act in a synergistic fashion. Both affect the ability of different bacterial species to create folic acid, a chemical that plays a critical role in bacterial growth, development, and reproduction. The two antibiotic medications inhibit successive steps in the reaction that creates folic acid, thus effectively cutting off the ability of the bacteria to live and thrive.

Typically SMZ-TMP is prescribed as pills. Often these pills contain 800 milligrams of sulfamethoxazole and 160 milligrams of trimethoprim, and typically patients take one to two tablets either once or twice a day. To treat patients who are severely ill and cannot take pills, the drug can also be administered in an intravenous formulation. The medication often goes by the brand names Bactrim® or Septra@reg;.

Many different bacterial infections can be treated with SMZ-TMP. It can be used to treat urinary tract infections, cellulitis, diarrhea, and respiratory tract infections. Often it is given prophylactically to patients with immunodeficiencies in order to prevent the development of certain types of pneumonia.

Common side effects of SMZ-TMP can include nausea, vomiting, headache, diarrhea, itching, abdominal pain, and rash. Rarely, some people taking the medication develop a severe side effect known as Stevens-Johnson syndrome and develop widespread redness and peeling of the skin, which in some cases can be life-threatening. In susceptible people, especially those with poor kidney function, the medication can injure the kidney and decrease its ability to properly filter the blood.

Although SMZ-TMP is typically well-tolerated, patients with certain medical conditions should not take the medication. Those who have allergies to chemical compounds in the sulfa class of drugs should not take this medication, as sulfamethoxazole is considered to be in this group. The presence of liver dysfunction, kidney impairment, or seizures could also be considered contraindications towards the use of this medication.

You might also Like

Readers Also Love

Discussion Comments


My daughter was prescribed this medication five days ago and now her feet are peeling just a little bit. She's supposed to take it three more days and I am wondering if it's OK to peel a little bit, or if the peeling will get worse and it's time to call the doctor. Does anybody have any experience with this drug?

Post your comments
Forgot password?
    • SMZ-TMP can be used to treat urinary tract infections.
      SMZ-TMP can be used to treat urinary tract infections.