Opioid intoxicação is a clinically significant transient condition that develops during or shortly after the consumption of opioids that is characterised by disturbances in consciousness, cognition, perception, affect, behaviour, or coordination. These disturbances are caused by the known pharmacological effects of opioids and their intensity is closely related to the amount of opioids consumed. They are time-limited and abate as opioids are cleared from the body. Presenting features may include somnolence, stupor, mood changes (e.g. euphoria followed by apathy and dysphoria), psychomotor retardation, impaired judgment, respiratory depression, slurred speech, and impairment of memory and attention. In grave intoxicação coma may ensue. A characteristic physical sign is pupillary constriction but this sign may be absent when intoxicação is due to synthetic opioids. grave opioid intoxicação can lead to death due to respiratory depression.