The opium (opium), morphine (morphine), codeine (codeine), compound formula camphor tincture (paregoric), and papaverine (papaverine) in this category are effective drugs for analgesia, cough suppression, diarrhea relief, anesthesia, and antispasmodic purposes, widely used in clinical practice. Accidental overdose or frequent use of morphine can lead to poisoning. The toxic dose of morphine for adults is 0.06g, and the lethal dose is 0.25g; the lethal dose of dry opium is 10 times that of morphine, with an oral lethal dose of 2–5g. The toxicity of codeine is one-fourth that of morphine, with a toxic dose of 0.2g and a lethal dose of 0.8g. Barbiturates and other hypnotic drugs have synergistic effects with this category of drugs, so caution is required when used together.

bubble_chart Etiology

The main active component of opium is morphine (approximately 10%), most of which is metabolized in the liver and excreted by the kidneys within 24 hours Neijing, with only trace amounts remaining in urine after 48 hours. Morphine initially excites the central nervous system before exerting a predominantly depressive effect. It first inhibits the higher centers of the cerebral cortex, then affects the medulla oblongata, depressing the respiratory center and stimulating the chemoreceptor trigger zone. Morphine enhances spinal cord excitability, increases the tone of gastrointestinal smooth muscle and its sphincters, reduces intestinal peristalsis, and has similar effects on the smooth muscles of the bronchi, bile ducts, and ureters.

Large doses of morphine can also inhibit the vasomotor center of the medulla oblongata and release histamine, leading to peripheral vasodilation, resulting in hypotension and bradycardia. Accidental overdose or frequent use of morphine can cause poisoning. The toxic dose of morphine for adults is 0.06g, and the lethal dose is 0.25g; the lethal dose of dry opium is 10 times that of morphine, with an oral lethal dose of 2–5g. The toxicity of codeine is one-fourth that of morphine, with a toxic dose of 0.2g and a lethal dose of 0.8g. Long-term use of morphine can induce euphoria and addiction. Patients with pre-existing chronic diseases such as liver disease, lung qi distension, bronchial asthma, anemia, thyroid disorders, or chronic adrenal insufficiency are more susceptible to poisoning. Concurrent consumption with alcoholic beverages, even at therapeutic doses of morphine, may lead to poisoning. Barbiturates and other hypnotic drugs have synergistic effects with this class of medications and should be used cautiously in combination.

Grade I acute poisoning patients exhibit headache, dizziness, nausea, vomiting, excitement, or depression. They may experience hallucinations, loss of time and space perception, as well as constipation, urinary retention, and elevated blood sugar. Grade III poisoning is characterized by three major symptoms: unconsciousness, pinpoint pupils, and severe respiratory depression. When spinal reflexes are heightened, convulsions, trismus, and opisthotonos often occur. Breathing initially becomes shallow and slow, followed by sighing respiration or Cheyne-Stokes breathing, frequently complicated by pulmonary edema. In the final stage of shock, the pupils dilate. Most acute poisoning cases result in death from respiratory paralysis within 12 hours or may be complicated by pulmonary infection. Those who survive beyond 48 hours have a better prognosis. Detection of toxins in urine or gastric contents aids in diagnosis.

Chronic poisoning (opium or morphine addiction) manifests as loss of appetite, constipation, emaciation, premature aging, and reduced sexual function. Withdrawal symptoms include mental fatigue, yawning, tearing, cold sweating, insomnia, and even collapse.

bubble_chart Treatment Measures

Upon discovering a poisoned patient, first determine the route of poisoning to expedite the removal of the toxic substance. For oral poisoning cases of longer duration, gastric lavage should still be performed, as small amounts of the drug may remain in the stomach for an extended period due to pyloric spasm. Avoid using apomorphine to induce vomiting. If an overdose of subcutaneous morphine is detected, quickly apply a tourniquet above the injection site and use cold compresses locally to slow absorption, intermittently loosening the tourniquet. In cases of respiratory depression, atropine can be used to stimulate the respiratory center, while ensuring airway patency and administering active oxygen therapy. Administer opioid antagonist detoxification agents as early as possible: naloxone via intramuscular or intravenous injection at 0.4–0.8 mg per dose, or nalorphine, which also counteracts morphine, at 5–10 mg intramuscularly or intravenously, repeating every 10–15 minutes if necessary. The total dose should not exceed 40 mg. In cases of severe poisoning, the dose per administration may be increased as appropriate. For chronic poisoning, gradually withdraw the drug over 2–3 weeks while managing symptoms with barbiturates and other sedatives.