A condition that follows the administration of opioids, resulting in disturbances in the level of consciousness, cognition, perception, judgement, affect, behaviour or other psychophysiological functions and responses. These disturbances are related to the acute pharmacological effects of, and learned responses to, opioids. With time, these disturbances resolve, resulting in complete recovery, except where tissue damage or other complications have arisen.

Intoxication depends on the type and dose of opioid, and is influenced by factors such as an individual's level of tolerance. Individuals often take drugs in the quantity required to achieve a desired degree of intoxication. Behaviour resulting from a given level of intoxication is strongly influenced by cultural and personal expectations about the effects of the drug.

Acute intoxication is the ICD-10 term for intoxication of clinical significance (F11.0). Complications may include trauma, inhalation of vomitus, delirium, coma and convulsions, depending on the substance and method of administration.