BT_PO 1.119 Describe the mode of action of protamine and potential adverse reactions

Unless you’re doing a cardiac term you won’t have much contact with this drug. However much badness can result from the intemperate use of this drug (even worse if you’ve forgotten to give the heparin in the first place!) so you need to know about it. Most of the important points are covered in the statements below and again I used Goodman and Gilman because I’ve recently bought self a copy. (Also used Stoelting cos there wasn’t much in G&G…annoying)

T/F  Protamine is a polypeptide drug derived from fish sperm and is positively charged

T/F  Protamine should be given slowly to reduce the risk of anaphylaxis

T/F  to antagonise unfractionated heparin the dose is approximately 1mg Protamine per 100 units of heparin

T/F  Protamine doesn’t antagonise LMWH at all

T/F  paradoxically, Protamine can cause an anticoagulant effect itself

T/F Protamine is cleared more rapidly than heparin and this accounts for the ‘heparin rebound’ effect

T/F Protamine is contraindicated in individuals with a seafood allergy

Bleedy McBleedster

BT_PO 1.121

Describe methods to reverse the effect of warfarin

BT_PO 1.120

Describe the pharmacology of warfarin and other anticoagulant drugs

The metabolic clearance of warfarin is inhibited by amiodarone. TRUE/FALSE

Third generation cephalosporins reduce the anticoagulant effect of warfarin. TRUE/FALSE

Intravenous vitamin K should return the prothrombin time to a normal range within 1 hour. TRUE/FALSE

Skin necrosis is a side effect of warfarin therapy. TRUE/FALSE

Warfarin can be reversed with recombinant factor VIIa TRUE/FALSE

Heparin

BT_PO 1.118 Describe the pharmacology of heparin and low molecular weight heparins including their side-effects

T/F All modern drugs now are produced by recombinant DNA technology.

Bull
Actually Heparin is still made from mammalian sources. Beginning in the 1940s heparin was manufactured from bovine lung and pig intestinal mucosa. Because of the BSE crisis, bovine heparin was voluntarily removed. This meant that most of the world’s supply of heparin came from pigs intestines from slaughterhouses in China.

In 2007 there was a crisis in which heparin was adulterated, which illustrated the problem of relying on a single source for a drug. There is now a suggestion that bovine heparin should be re-introduced into clinical practice.

 

 

T/F Both fractionated and unfractionated heparin require anti-thrombin as a cofactor

T/F Heparin exhibits a 4 fold variation in sensitivity and 3 fold variation in its rate of metabolism between patients

T/F The half life of heparin is 1-2 hours and varies directly with the total dose

T/F Heparin induced thrombocytopaenia is the result of a non-specific immune reaction

T/F Heparin is cleared from the circulation by hepatic mechanisms alone