Different drugs, different sides: injection use of opioids alone, and not stimulants alone, predisposes to right-sided endocarditis.

While injection use of opioids is associated with a strong predisposition to right-sided IE, stimulants differ in producing a balanced ratio of right and left-sided disease. As the epidemic of crystal methamphetamine injection continues unabated, the rate of left-sided disease, with its attendant higher morbidity and mortality, may also grow.