In many states laws prohibit driving if the driver is impaired by any drug. Patients should be told not to drive whenever an opioid is started or the dose increased and to refrain from driving for at least a week or longer, until normal cognitive and motor skills are fully recovered. Individual state regulations should be reviewed regarding the operation of motor vehicles and the ingestion of many drugs including opioids. Meperidine is an opioid analgesic with 75 mg. Oral equivalent doses would be 300 mg. and 30 mg., respectively.
Meperidine is metabolized to an active metabolite normeperidine.
This drug is twice as potent as a convulsant and half as potent as an analgesic as its parent compound. This can result in confusion, tremors, multifocal myoclonus, and seizures. It is even more problematic in patients with renal failure. Naloxone is not effective in treating these seizures and in fact, may precipitate them in patients with high levels of normeperidine. Although meperidine causes a lesser rise in common bile duct pressure than morphine, this has never been shown to be clinically significant.