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Meperdine (me-per-i-dine) (Demerol, Pethedine, Lidol, Pethanol, Alodan and Dispadol) is a fast-acting opioid analgesic drug used for the treatment of moderate to severe pain.  It is most commonly known by its brand name, Demerol.  It is administered in tablets, syrup or by intramuscular or intravenous injection.


Meperidine causes users to experience marked euphoria because it triggers the brain's pleasure centers while it blocks pain.

Meperidine's effects are felt a few minutes after ingestion and last from two to four hours.  Meperidine’s effects are similar to morphine, but with sedation, respiratory depression, and euphoria less intense than morphine.  Nausea and vomiting are common with oral use but less likely when administered by injection.


For much of the 20th century Meperidine was the opioid of choice for many physicians.

Meperidine was considered to be safer and to carry less risk of addictionthan Morphine.  It was also thought to be superior in treating pain due to its antispasmodic effects.  Physicians now consider Meperidine to be no more effective than Morphine in treating pain. In addition, its low potency, short duration, and toxicity has caused it to lose popularity in recent years.

Meperidine toxicity can result in seizures, delirium, and other serious neuropsychological effects.


The side effects of Meperidine are similar to those of other opiods: nausea, vomiting, sedation, dizziness, urinary retention and constipation. Meperidine overdose can cause muscle flaccidity, respiratory depression, cold and clammy skin, hypotension, and coma.


Fatalities have occurred with both oral and intravenous Meperidine overdose.


Serotonin syndrome, a potentially life-threatening build up of excess serotonin in the brain, has occurred in patients taking Meperidine during antidepressant therapy or with selective serotonon reuptake inhibitors (SSRIs) or monoamine oxidase inhibitors (MOIs).

Despite being structurally distinct from Morphine and related opiates, Meperidine's effects on opiate receptors in the brain are similar to those of morphine.


The major hazard of Demerol is respiratory depression, but other risks include circulatory depression, respiratory arrest, shock, and cardiac arrest.


Physical tolerance and psychological dependence can develop, especially with excessive doses or long-term use.  Stopping usage abruptly after prolonged or high dosage can result in extreme fatigue and mental depression.

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