opiate /ō″pē·it/ [Gk, opion, poppy juice] , 1. a drug that contains opium, derivatives of opium, or any of several semisynthetic or synthetic drugs with opium-like activity. 2. (Informal) any soporific or opioid drug. 3. pertaining to a substance that causes sleep or relief of pain. Morphine and related opiates may produce unwanted side effects such as respiratory depression, nausea, vomiting, dizziness, and constipation. Patients with reduced blood volume are more susceptible to the hypotensive effect of morphine and related drugs. Opiates are used with extreme caution in obese patients and in those with head injuries, emphysema, or other problems associated with decreased respiratory function. In patients with prostatic hypertrophy, morphine may cause acute urinary retention, requiring repeated catheterization. Also called opioid.
