Table 1.  Pharmacokinetic Characteristics of Several Sulfonamides

 

Sulfonamide

Adult Dose

Peak Level (μg/mL)

T½

Protein Binding

Risk of Crystalluria

Sulfisoxazole

4-8 g/day

120-200

4-6 h

85%

Low

Sulfamethoxazole

2-3 g/day

60-80

5-15 h

65%

Low

Sulfadiazine

2-4 g/day

50-100

6-16 h

55%

Moderate

Sulfadoxine

500 mg/week

50-75

5-10 day

95%

Low

Sulfasalazine

2-4 g/day

10-25

4-7 h

See sulfapyridine

Low

Sulfapyridine

See sulfasalazine

15-45

6-9 h

25%

High

 

 

Figure 1.   Structures of clinically useful sulfonamides.