The notion that drugs can induce valvular heart disease (VHD) has occurred since the sixties and has received a lot of attention in recent years. Overstimulation of the serotonin 2B receptor (5-HT2B) leads to valvular fibroblast proliferation and thickening of the valvular leaflets with reduced mobility and regurgitation as a consequence. This book focuses on different aspects of this distinct kind of valvulopathy including pathophysiology of drug-induced VHD, histopathological and echocardiographic characteristics,drugs associated with VHD, the influence of cumulative drug dose and risk factors and others.