From Longman Dictionary of Contemporary Englishbe doped (up)be doped (up)British English to be unable to think or behave normally, because of the effects of drugs or alcoholbe doped (up) on She was doped up on drink and drugs most of the time. → dope
Examples from the Corpus
be doped (up)• I still half expect the food to be doped.• In February five greyhounds were found to be doped after an £60,000 multi-bet coup in the first race at Canterbury.• Kerr-McGee charged she was doped up with Quaaludes.