To treat a urinary tract infection (UTI), a client is prescribed sulfamethoxazole (Gantanol), 2 g by mouth initially, and then 1 g by mouth three times daily. The nurse should teach the client that sulfamethoxazole is most likely to cause which adverse effect?

To treat a urinary tract infection (UTI), a client is prescribed sulfamethoxazole (Gantanol), 2 g by mouth initially, and then 1 g by mouth three times daily. The nurse should teach the client that sulfamethoxazole is most likely to cause which adverse effect?

• A. Diarrhea
• B. Nausea
• C. Dizziness
• D. Headache

Answer: (A)

GI upset from this sulfonamide antibiotic is common, and diarrhea is the most frequent adverse effect. Its broad action disrupts normal intestinal flora and can irritate the GI tract, leading to loose stools more often than nausea, dizziness, or headaches. Encourage fluids and monitor for persistent or severe diarrhea, especially with fever or abdominal pain, which could indicate antibiotic-associated colitis.

GI upset from this sulfonamide antibiotic is common, and diarrhea is the most frequent adverse effect. Its broad action disrupts normal intestinal flora and can irritate the GI tract, leading to loose stools more often than nausea, dizziness, or headaches. Encourage fluids and monitor for persistent or severe diarrhea, especially with fever or abdominal pain, which could indicate antibiotic-associated colitis.