It can be a side effect of Ritalin (methylphenidate), Adderall (dextro/levo-amphetamine) and Lunesta (
eszopiclone) and other prescription drugs or of cocaine or amphetamines. (Accordingly, it goes by the slang term "coke bugs".) Formication also be a withdrawal symptom of weaning oneself off of cocaine or amphetamine. It can also accompany alcohol withdrawal in alcoholics, along with delirium tremens, and can often be accompanied by visual hallucinations of insects.