Agonists

There’s something rotten about a drug group known as the ‘agonists’. There are agonists for Parkinson’s disease, appetite suppression and migraine headache. The ‘recreational’ drug ecstasy is also an agonist.

These agents work by binding to the receptor of a cell, thereby trig-gering a response, and often mimick the actions of a naturally occurring substance in the body.

But there’s something wrong with the science. The agonist appetite suppressant fenfluramine is banned, while the agonists for migraine have long been suspected of causing heart disease. 

Now, researchers have discovered that two agonists used for Parkinson’s —Celance (pergolide) and Cabaser (cabergoline; sold as Dostinex in the US)—can cause serious heart disease affecting the heart valves.

Compared with a placebo, the drugs increased the risk of valvular heart disease from between five and seven times (N Engl J Med, 2006; 356: 29–38).