As nouns the difference between papaverine and opium

is that papaverine is a non-addictive derivative of opium used in medicine to relieve muscle spasms, as a vasodilator and in some forms of erectile dysfunction while opium is a yellow-brown, addictive narcotic drug obtained from the dried juice of unripe pods of the opium poppy, Papaver somniferum, and containing alkaloids such as morphine, codeine, and papaverine.