Sulfadiazine (as well as other sulfonamides) may form crystals in the renal tubules resulting in tubular obstruction and renal failure.


Uses of sulfadiazine:

(1) toxoplasmosis, especially in HIV-positive patients

(2) Pneumocystis carinii (jirovecii)

(3) topical therapy in burns

(4) urinary tract infection

(5) Shigella dysentery

(6) prophylaxis for meningococcemia


Risk factors for nephropathy:

(1) dehydration or poor fluid intake

(2) acidic urine

(3) prolonged use at high doses

(4) pre-existing renal disease


Clinical findings:

(1) flank or lumbar pain

(2) oliguria or anuria with acute renal failure

(3) gross or microscopic hematuria

(4) proteinuria

(5) urine crystals in the form of "sheaves of wheat"

(6) occasionally nephrolithiasis



(1) use the lowest possible effective dose

(2) promote diuresis with fluid intake > 2 liters per day

(3) alkalinize the urine to a pH > 7.15, often with sodium bicarbonate

(4) in severe cases consider direct pelvic irrigation with sodium bicarbonate or hemodialysis


To read more or access our algorithms and calculators, please log in or register.