Final answer:
Sulfasalazine is a sulfonamide that inhibits bacterial folic acid synthesis leading to bacteriostatic effects; it requires caution in administration due to common sulfa allergies and potential for folic acid deficiency diseases. It is used in combination treatments for toxoplasmosis and malaria but requires careful use during pregnancy to avoid birth defects.
Step-by-step explanation:
Sulfasalazine (Azulfidine) is a medication that belongs to a class of drugs known as sulfonamides or sulfa drugs. These drugs act as competitive inhibitors of the enzyme sulfihydropteroate synthase, which converts para-aminobenzoic acid (PABA) into dihydrofolic acid, an essential precursor for folic acid synthesis in bacteria. By blocking this pathway, sulfonamides prevent bacterial synthesis of folic acid, as well as pyrimidines and purines, which are necessary for nucleic acid synthesis, leading to a bacteriostatic effect on a wide spectrum of gram-positive and gram-negative pathogens.
Humans, on the other hand, obtain folic acid through their diet, meaning sulfonamides are selectively toxic to bacteria. Despite their effectiveness, allergic reactions to sulfa drugs are common. Nursing considerations for administering sulfasalazine include careful prescription due to the potential for sulfa allergies, distinguishing it from other sulfur-containing compounds like sulfates and sulfites, and monitoring for potential deficiency diseases like megaloblastic anemia resulting from inhibited microbial folic acid synthesis.
Sulfonamides are also utilized in the treatment of diseases such as toxoplasmosis and malaria, often in combination with other drugs like pyrimethamine. However, care must be taken during pregnancy, especially in the first trimester, due to the risk of birth defects associated with these drugs. Alternatives such as spiramycin may be used to reduce transmission of infections like toxoplasmosis without the risk of crossing the placenta.