Meperidine [Demerol], a mu opioid analgesic, is commonly used for postoperative pain control. Meperidine is commonly underdosed and administered too infrequently even by physicians aware of its pharmacokinetics (Marks and Sachar, 1973). The common postoperative meperidine order of 75 mg parenterally every 4 hours as needed often is inadequate for several reasons. Meperidine produces clinical analgesia for only 2.5-3.5 hours, and a dose of 75 mg every 4 hours is equivalent to only 5-7.5 mg of morphine. Therefore, to obtain postoperative analgesia equal to that from 10 mg of morphine sulfate every 4 hours, a clinician would have to use 100-150 mg of meperidine every 3 hours. Because of its unique toxicity, meperidine is often contraindicated in patients with impaired renal function and those receiving antidepressants of the monamine oxidase inhibitor class (Wood and Cousins, 1989). Normeperidine (6-N-desmethylmeperidine) is a toxic meperidine metabolite excreted through the kidney. In patients with normal renal function, normeperidine has a half-life of 15 to 20 hours; this time is extended greatly in elderly individuals and patients with impaired renal function. Normeperidine is a cerebral irritant that can cause effects ranging from dysphoria and irritable mood to convulsions (Kaiko, Foley, Grabinski, Heidrich, Rogers, Inturissi, and Reidenberg, 1983; Sieto, Inturrisi, Houde, Saal, Cheigh, and Reidenberg, 1977). These effects have been observed even in young, otherwise healthy patients given sufficiently high doses of normeperidine postoperatively. Therefore, meperidine should be reserved for very brief courses in otherwise healthy patients who have demonstrated an unusual reaction (e.g., local histamine release at the infusion site) or allergic response during treatment with other opioids such as morphine or hydromorphone.
Note: Exercise caution when using the mixture of meperidine (Demerol), promethazine (Phenergan), and chlorpromazine (Thorazine), also known as DPT. DPT-given intramuscularly-has commonly been used for painful procedures. The efficacy of this mixture is poor when compared with alternative approaches, and it has been associated with a high frequency of adverse effects (Nahata, Clotz, and Krogg, 1985). It is not recommended for general use and should be used only in exceptional circumstances.
From Acute Pain Management Guideline Panel. Acute Pain Management Operative or Medical Procedures and Trauma. Clinical Practice Guidelines. AHCPR Pub. No. 92-0032. Rockville, MD: Agency for Health Care Policy and Research, Public Health Service, U.S. Department of Health and Human Services. Feb. 1992. 800-358-9295 . . .
Assess the child at least every 8 hours for early signs of
normeperidine toxicity, such as tremors in the outstretched hand, episodes of
twitching or jerking, or increased agitation or excitability (may be upset
easily). If toxicity is suspected, discontinue the meperidine, maintain the IV,
and notify the practitioner (Love, 1994). If symptoms worsen, a CNS depressant
may be needed. The pharmacist should complete an adverse drug reaction report
(Form 3500A) to MedWatch.
The FDA Medical Products Reporting
Program, Food and Drug Administration, 5600 Fischers Lane, Rockville, MD
20852-9787; (800) FDA-1088; Fax: (800) FDA-0178.
Love G; The Dangers of Normeperidine Toxicity, American Journal of Nursing 94(6):14, 1994.
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