Wardround 2xii05

The theme this week was anti-arrhythmics and the Vaughan-Williams classification. This classification is not perfect since within a class, drugs may have different actions and drugs may exist in more than one class. It is, however, a good starting point for understanding anti-arrhythmics.

Class I agents interfere with the sodium (Na+) channel.
Class 1a eg disopyramide, prolong the action potential. They are effective against SVT and VT.
Class 1b eg lignocaine, shorten the action potential. They are used for the treatment of VT.
Class 1c eg flecainide, have little effect on the action potential duration. They are effective in AF, SVT and VT
Class II agents are beta blockers.
Class III agents affect potassium (K+) influx. eg amiodarone prolong the action potential and refractory period. They are used for re-entry tachycardias, SVT and VT.
Class IV agents affect the AV node.

An excellent summary can be found at:
http://lysine.pharm.utah.edu/netpharm/netpharm_00/notes/antiarrhythmics.html

Next week’s theme is reducing drug risks and we will be using rheumatological drugs as our examples. The challenge is to wax lyrical for two minutes about reducing risk when using:

Methotrexate (HG)
Leflunomide (CT)
Sulfasalazine (NM)
Etanercept (Ash)
Steroids (MJM)
(and if GAJ wishes she can have any antibiotic used long term...minocycline would be rheumatological)

The reading for next week is
Nonsteroidal anti-inflammatory drug associated gastropathy: incidence and risk factor models. Fries JF, Williams AW. The American Journal of Medicine. 1991; 91: 213-222.
You will need to get this from the elibrary

Interesting topics this week?

NFRs

Decisions Relating to Cardiopulmonary Resuscitation. A Joint Statement from the British Medical Association, the Resuscitation Council (UK) and the Royal College of Nursing. February 2001.

UK clinical ethics network

Acute inflammatory arthritis

Guidelines for the Initial Evaluation of the Adult Patient with Acute Musculoskeletal Symptoms. American College of Rheumatology.

MJM