Avoid using sulfonamides if the patient is allergic to one member of the
sulfonamide family of medication. Sulfonamides should not be administered
to neonates.
Sulfonamides may adversely affect the level of some medications causing a
toxic effect. Avoid using sulfonamides with anticoagulants such as coumarin
or indanedione derivatives and anticonvulsants (hydantoin) as well as oral anti-
diabetic agents and methotrexate.
Patients need at least 3000 mL of fluid each day in order to flush theurinary
tract and follow good hygiene to reduce the likelihood of acquiring the infec-
tion again. The patient should be instructed to drink at least three quarts of water(^242) CHAPTER 13 Antimicrobials—Fighting Infection
Sulfonamides
Pregnancy Category: C
Route Dose Time
Sulfadiazine
Protein-Binding: 20–30%
Half-Life: 8–12 hours
PO 2–4 mg first dose 7–10 days
Drink 250 mL H 2 O 2–4 g subsequent
with each dose
Sulfisoxazole (Gantrisin):
Protein-Binding: 60–70% (TMP-SMX)
Half-Life: 7–12 hours
PO 2–3 g/d in 2–3 7–10 days
divided doses
Trimethoprim-sulfamethoxazole
Protein-Binding: 50–65% (TMP-SMX)
Half-Life: 8–12 hours
Most widely used antibacterial agent in the world
PO 160/800 mg q12h
Sulfamethoxazole (co trimoxazole) (TMP)
Protein-Binding: 99%
Half-Life: 5.5 hours
PO 160 mg TMP BID
IV 20 mg/kg q6hr