Overview
This lecture covers sulfonamides (sulfa drugs), their key characteristics, uses, side effects, and important nursing considerations.
Sulfonamides Overview
- Sulfonamides are antibiotics commonly called sulfa drugs.
- Drugs that start with "sulfa", like sulfamethoxazole and sulfadiazine, are sulfonamides.
- Sulfonamides are different from sulfonylureas, which are diabetic medications.
Mechanism of Action
- Sulfonamides kill bacteria but are not effective against viruses or fungi.
- They work by blocking the synthesis of folic acid required for bacterial growth.
Clinical Uses
- Used to treat a wide variety of bacterial infections.
Adverse Effects & Precautions
- Sulfa allergies are common and may cause allergic reactions; monitor patients closely, especially on first exposure.
- Cross-sensitivity may occur with other sulfa-derived drugs, such as sulfonylureas and thiazide diuretics.
- Can cause crystalluria (urine crystals), which may lead to kidney stones and damage.
- May cause photosensitivity, increasing risk of sunburn.
- Can lead to folate deficiency by inhibiting folic acid synthesis.
- Sulfonamides are teratogenic (harmful to fetus) and should be avoided in pregnancy.
Nursing Considerations
- Advise patients to stay well-hydrated (at least 2 liters/day) to prevent crystalluria.
- Counsel patients to use sunblock, wear protective clothing, and avoid direct sunlight.
- Patients may need folic acid supplementation.
- Ensure pregnant women do not take sulfonamides.
Key Terms & Definitions
- Sulfonamides — Antibiotics that start with "sulfa" and kill bacteria by blocking folic acid synthesis.
- Crystalluria — Presence of crystals in urine, can cause kidney damage.
- Photosensitivity — Increased sensitivity to sunlight, leading to higher risk of sunburn.
- Teratogenic — Causes developmental defects in a fetus.
Action Items / Next Steps
- Review names and indications for common sulfonamides.
- Memorize key side effects, especially allergy, crystalluria, and teratogenicity.
- Practice patient education points on hydration, sun safety, and folic acid for exams.