special subjects
Opioid Toxicity and Withdrawal
Symptoms and Signs of Opioid Toxicity or Withdrawal
Acute opioid intoxication is characterized by euphoria and drowsiness. Mast cell effects (eg, flushing, itching) are common, particularly withmorphine. Gastrointestinal effects include nausea, vomiting, decreased bowel sounds, and constipation. The main toxic effect is decreased respiratory rate and depth, which can progress to apnea. Other complications (eg, pulmonary edema, which usually develops within minutes to a few hours after opioid overdose) and death result primarily from hypoxia. Pupils are miotic. Delirium, hypotension, bradycardia, decreased body temperature, and urinary retention may also occur. Normeperidine, a metabolite ofmeperidine, accumulates with repeated use (including therapeutic); it stimulates the central nervous system and may cause seizure activity. Serotonin Syndrome occasionally occurs when Hypertonia Tremor and hyperreflexia Spontaneous, inducible, or ocular clonus Diaphoresis and autonomic instability Agitation Temperature>38° plus ocular or inducible clonus Although rare among inhalational heroin users, spongiform leukoencephalopathy has been reported. The symptoms depend on the timing of presentation and may show motor restlessness, apathy, ataxia, or paralysis. The symptoms may resolve, or can progress to autonomic dysregulation and death. The opioid withdrawal syndrome usually includes symptoms and signs of central nervous system hyperactivity. Onset and duration of the syndrome depend on the specific drug and its half-life. Symptoms may appear as early as 4 hours after the last dose of heroin, peak within 48 to 72 hours, and subside after about a week. Anxiety and a craving for the drug are followed by increased resting respiratory rate (>16 breaths/minute), usually with diaphoresis, yawning, lacrimation, rhinorrhea, mydriasis, and stomach cramps. Later, piloerection (gooseflesh), tremors, muscle twitching, tachycardia, hypertension, fever and chills, anorexia, nausea, vomiting, and diarrhea may develop. Opioid withdrawal does not cause fever, seizures, or altered mental status. Although it may be distressingly symptomatic, opioid withdrawal is not fatal. The withdrawal syndrome in people who were takingmethadone(which has a long half-life) develops more slowly and may be less acutely severe than heroin withdrawal, although users may describe it as worse. Even after the withdrawal syndrome remits, lethargy, malaise, anxiety, and disturbed sleep may persist up to several months. Drug craving may persist for years. 