Among similar antiparkinsonian drugs, cabergoline exhibits the same type of serotonin receptor binding as pergolide. Although lisuride, a related drug, also binds to the 5-HT2B receptor, it acts as an antagonist rather than as an agonist.In January 2007, cabergoline (Dostinex) was reported also to be associated with valvular proliferation heart damage. Recreational drugs
Several serotonergic recreational drugs, including the empathogens MDA and MDMA ("ecstasy"), and some hallucinogens such as DOI and Bromo-DragonFLY, have all been shown to act as 5-HT2B agonists in vitro, but how significant this may be as a risk factor associated with their recreational use is unclear. The piperazine derivative mCPP (a major metabolite of trazodone) is a 5-HT2B agonist in animal models, but actually behaves as a 5-HT2B antagonist in humans. MDMA
One study of human users of MDMA ("ecstasy") found that they did have heart valve changes suggestive of early cardiac fibrosis, which were not present in non-MDMA using controls, suggesting that MDMA use certainly has the potential to cause this kind of heart damage.On the other hand, there is as yet no statistical evidence to establish or negate significant increases in rates of cardiac valvopathies in current or former MDMA users. Absent studies on point, it may be speculated that as with other 5-HT2B agonists, development of heart valve damage may be dependent on the frequency and duration of use and the total cumulative exposure over time. If that is the case, then the heaviest users are likely to face the greatest risk of heart damage.
Anorectics
Some appetite suppressant drugs such as fenfluramine (which in combination with phentermine was marketed as Pondimin and commonly referred to as fen-phen), chlorphentermine, and aminorex (along with its analogue 4-Methylaminorex which has seen sporadic use as a recreational drug) induce a similar pattern of cardiac fibrosis (and pulmonary hypertension), apparently by overstimulating 5HT2B receptors on the cardiac fibroblast cells.These drugs consequently tend to cause increased risk of heart valve damage and subsequent heart failure, which eventually led to them being withdrawn from the market. Antimigraine drugs
Certain antimigraine drugs which are targeted at serotonin receptors as vasoconstrictive agents, have long been known to be associated with pulmonary hypertension and Raynauds phenomenon (both vasoconstrictive effects), as well as retroperitoneal fibrosis (a fibrotic cell/fibrocyte proliferation effect, thought to be similar to cardiac valve fibrosis).These drugs include ergotamine and methysergide and both drugs can also cause cardiac fibrosis. Antiparkinson drugs
Certain antiparkinson drugs, although targeted at dopaminergic receptors, cross-react with serotoninergic 5-HT2B receptors as well, and have been reported to cause cardiac fibrosis. These drugs include pergolide and cabergoline. Antihypertensive drugs
Guanfacine may be a 5-HT2B agonist, based on the results of theoretical modeling and high-throughput screening. Pergolide
Pergolide was an antiparkinson medications that was in decreasing use since reported in 2003 to be associated with cardiac fibrosis. In March 2007, pergolide was withdrawn from the U.S. market due to serious valvular damage that was shown in two independent studies. Cabergoline
Like pergolide, cabergoline has been linked to cardiac damage.