Rituximab dosing schedule?

• A. IV 250-500 mg weekly x 4
• B. IV 1000 mg every 3 weeks
• C. IV 500-1000 mg x 2 doses given 2 weeks apart
• D. IM 600 mg monthly

Answer: (C)

Rituximab works by depleting CD20+ B cells, which drive many autoimmune skin diseases. For autoimmune indications, the typical dosing is two intravenous infusions given about 2 weeks apart, usually around 1000 mg per dose (though 500 mg per dose can be used in some patients). This two-dose, two-week interval achieves rapid B-cell depletion and often durable disease control, with the option to redose later if needed. The medication is given IV because that route provides reliable bioavailability and the rapid B-cell hit that these conditions require; other schedules—such as a weekly course, infusions every 3 weeks, or an IM administration—do not match the standard autoimmune regimen.