Explain What Type Of Drug Is Trimethoprim And Sulfamethoxazole

1. What type of drug is trimethoprim/sulfamethoxazole and how does it work?

Trimethoprim/sulfamethoxazole (Bactrim) is an antibacterial drug, also classified as a metabolism inhibitor. This drug interferes with bacterial reproduction by preventing the bacteria from producing folic acid. Specifically, this drug prevents a specific enzyme from converting substances into folic acid, which is needed by the bacteria to make DNA and reproduce. Therefore, the bacteria do not have enough folic acid to make DNA and grow further. Trimethoprim/sulfamethoxazole is considered bacteriostatic rather than bactericidal. Bacteriostatic antibiotics prevent bacteria from growing until the body’s own white blood cells (WBCs) and antibodies get rid of them, and bactericidal antibiotics kill the bacteria directly.
Although trimethoprim/sulfamethoxazole are classified as antibacterial drugs, metabolism inhibitors can be effective in infections caused by organisms other than bacteria. These drugs are most commonly used to treat urinary tract infections (UTIs), middle ear infections, pneumonia, and infectious diarrhea. Lastly, sulfonamides and trimethoprim are not only available as oral and IV medications, but are also available as creams, lotions, eye drops, and ointments.

2. Is it okay for her to stop taking this drug as soon as the symptoms are gone? Why or why not?

It is not okay for the patient to discontinue her medication, once the symptoms have subsided. The medication should be taken as directed, 1 tablet every 12 hours for the entire duration of 14 days. It is essential for the patient to take her entire prescription as directed by the doctor or the UTI could reoccur. If the patient were to stop taking the medication when symptoms subside the bacteria could still be present within the body possibly causing a second UTI, as well as the remaining bacteria becoming resistant to the drug therapy further complicating the patient.

3. What are the side effects of this drug?

Side effects of trimethoprim/sulfamethoxazole (Bactrim) include nausea, vomiting, headache and severe itching (pruritus). Sulfonamides are a type of chemical that can easily turn into crystals. Adverse effects include crystal formation that can clump in the kidneys, which can lead to and cause kidney failure or kidney stones. One of the most severe adverse effects of metabolism inhibitors is the suppression of bone marrow cell division. Suppression of bone marrow cell division results in fewer red blood cells (anemia) and fewer WBCs. Some patients are affected only slightly; and for others suppression can be so great they are at an increased risk for infections. Lastly, a simple skin rash can occur with metabolism inhibitors, but more serious skin problems are possible. More severe skin problems include peeling and sloughing, blister formation, and a combination of many types of skin eruptions known as Stevens-Johnson syndrome. Stevens-Johnson syndrome is a life threatening adverse effect, and can lead to life-threatening losses of fluids and electrolytes.

4.
What precautions and actions will you teach her about this drug therapy?

As a precautionary measure, metabolism inhibitors should be avoided in any person who has a genetic disorder called glucose-6-phosphate dehydrogenase (G6PD) deficiency, which causes red blood cells to break. G6PD is most common among males of African-Americans and or Mediterranean decent. In addition, thiazide diuretics should not be prescribed with trimethoprim/sulfamethoxazole (Bactrim). Combining these drugs can greatly increase the risk of anemia and bleeding.
Other special considerations and precautions include skin care protection. The patient will be educated on how to reduce photosensitivity. Ways to reduce photosensitivity and possible sunburn includes avoiding direct sunlight, using sunscreen, and to wear protective clothing including a hat when in the sun is necessary. Educating the patient to drink a full glass of water when taking her sulfonamide or trimethoprim tablets, as well as increased fluids throughout the day is critical. Drinking an adequate amount of water with the patient’s medication is important to prevent the formation of crystals in the urine and or clogging the
kidneys. Most importantly, when teaching the patient about precautions and actions about her drug therapy it is crucial she understands what is being taught to her. If she does not understand a portion of her drug therapy education, further information will be given to her to ensure medication compliance, safety, and knowledge.