COX-2 Inhibitors

00:01 Let's move on to a different class of drugs called the cyclooxygenase 2 inhibitors or COX-2 inhibitors.

00:07 There are several different variation of cyclooxygenase. COX-1, COX-2, COX-3. So these are COX-2 inhibitors.

00:15 These are very effective pain medications. And the nice thing about these pills is that they have reduced GI side effects.

00:23 They also reduce the risk of colon cancer which is kind of a bonus.

00:27 They have a mild increased risk however of myocardial infarction and arterial thrombosis which is why these medications are a little bit more controversial in the sense that there's a lot of people saying "Are they really worth the increased cost?" Now, we have an increased reduction in prostaglandin 1 or prostaglandin I formation and also we are not sure what its effect is on thromboxane A2.

00:53 Now, prostacyclin promotes vasodilation and inhibits platelet aggregation.

00:58 Perhaps this is a mechanism that makes this issue relevant here. Thromboxane A2 inhibits vasodilation and promotes platelet aggregation.

01:07 We believe that perhaps thromboxane A2 activity may be the culprit of how myocardial infarction occurs with the COX-2 inhibitors.

01:17 Suffice to say we are not really sure.

01:19 The prototypical example of this medication is celecoxib, also sold as Celebrex. This was the first member of this new group.

01:31 Now, rofecoxib which was Vioxx and valdecoxib which was Bextra are also both more specific to COX-2.

01:38 These two products were taken off the market by their manufacturers.

01:43 Now the reason why these drugs were taken off the market, in my opinion it was silly, I think that they were just being misused by physicians who didn't know how to use the drugs.

01:53 Suffice it to say, one physician in Australia using 8 times the regular dose of this drug and killing his patients, ended up resulting in taking away medication that were used all over the world.

02:04 They were relatively good drugs but not available anymore.

02:07 And I think the only relevant drug in this class left is Celebrex.