Pharmacology for Anaesthesia and Intensive Care

P1: PCX Printer: Yet To Come
9780521704632c09 CUFX213A/Peck 9780521618168 December 28, 2007 11:33

9 Analgesics

O

O

O

Rofecoxib

Etoricoxib

Celecoxib

O

CI

N N

S

OO O

S

CH 3 SO 2 H 3 C

O

N

CH 3

Valdecoxib

CF 3

SO 2 NH 2

NH 2 SO 2

Parecoxib O

N N

N

N

H

Figure 9.5.Structures of some COX-2 inhibitors.

(50%). Three percent is excreted unchanged in the urine. The elimination half-life is

20 hours.

Specific COX-2 inhibitors

Itis possible that by the time this edition goes to print further COX-2 inhibitors will

have been withdrawn from the market due to concerns about myocardial infarction

(MI) and stroke. It is currently unclear if these concerns revolve around individual

drugs or the entire class of COX-2 inhibitors.

Initially, large studies suggested that there was a significantly reduced incidence

of gastrointestinal side effects associated with COX-2 inhibitors compared with

standard NSAIDs. However, the Food and Drug Administration (FDA) later pre-

sented further data that exposed the increased MI and stroke rates but also a