indication

For treatment of CD20-positive non-Hodgkins lymphoma, chronic lymphocytic leukemia, and rheumatoid arthritis.

pharmacology

Rituximab binds to the CD20 antigen, which is predominantly expressed on mature B cells and on >90% of B-cell non-Hodgkin's lympohomas. The antibody leads to selective killing of B-cells.

mechanism of action

The Fab regions of rituximab binds to the CD20 antigen on B lymphocytes, while the Fc domain recruits antibodies and complements to mediate cell lysis.

biotransformation

Most likely removed by opsonization via the reticuloendothelial system when bound to B lymphocytes, or by human antimurine antibody production

half life

0.8 hours (mammalian reticulocytes, in vitro)

drug interactions

Betaxolol: Antihypertensives like betaxolol may enhance the hypotensive effect of rituximab. Consider temporarily withholding antihypertensive medications for 12 hours prior to rituximab infusion to avoid excessive hypotension during or immediately after infusion.

Chlorothiazide: Antihypertensives such as chlorothiazide may enhance the hypotensive effect of Rituximab. Consider temporarily withholding antihypertensive medications for 12 hours prior to rituximab infusion to avoid excessive hypotension during or immediately after infusion.

Telmisartan: Telmisartan may increase the hypotensive effect of Rituximab. Telmisartan should be withheld prior to and throughout Rituximab administration.

Terazosin: Additive antihypertensive effects may occur. Increased risk of hypotension. Consider withholding Terazosin for 12 hours prior to administration of Rituximab.

Tolazamide: Additive hypotensive effects may occur. Consider withholding Tolazamide for 12 hours prior to administration of Rituximab.

Torasemide: Additive antihypertensive effects may occur. Increased risk of hypotension. Consider withholding Torasemide for 12 hours prior to administration of Rituximab.

Trandolapril: Trandolapril may incresae the hypotensive effect of Rituximab.

Trastuzumab: Trastuzumab may increase the risk of neutropenia and anemia. Monitor closely for signs and symptoms of adverse events.

Trichlormethiazide: Additive antihypertensive effects may occur. Increased risk of hypotension. Consider withholding Trichlormethiazide for 12 hours prior to administration of Rituximab.

Valsartan: Additive hypotensive effects may occur. Increased risk of hypotension. Consider withholding Valsartan for 12 hours prior to administration of Rituximab.

Verapamil: Verapamil may increase the hypotensive effects of Rituximab. Consider withholding Verapamil therapy for 12 hours prior to Rituximab infusion.