Norfenfluramine

Norfenfluramine is a metabolite of the anorectic drugs fenfluramine and benfluorex. It has been implicated in the valvular heart disease observed in patients treated with these drugs, as it is a potent agonist at the 5-HT2B receptor, which is highly expressed in human heart valves. The damage caused by norfenfluramine to heart valves is thought to result from excessive stimulation of these receptors, leading to proliferative disease of the valve interstitium.

Pharmacology[edit]

Norfenfluramine, like other serotonergic drugs, has been associated with serotonin syndrome. This is a potentially life-threatening condition that can occur rapidly after the administration of serotonergic drugs. Symptoms may include agitation, restlessness, confusion, rapid heart rate, dilated pupils, loss of muscle coordination, heavy sweating, diarrhea, headache, shivering, and goosebumps.

History[edit]

Norfenfluramine was discovered in the 1960s and was used as an appetite suppressant in the treatment of obesity. However, it was withdrawn from the market in many countries in the late 1990s due to concerns about its safety, particularly its association with valvular heart disease.