Fast Fact and Concept #71: Meperidine for pain: what is all the fuss?
Author: David E. Weissman
What is it? Meperidine (MP) is a synthetic opioid, chemically
related to the anti-diarrhea agents diphenoxylate and loperamide (Immodium).
MP produces analgesia by binding to the mu opioid receptor, as does
morphine, producing the same effects and toxicities as morphine. 75-100 mg
of parenteral MP = 10 mg parenteral MS; MP has a shorter duration of
action than Morphine, only 2.5-3.5 hours. Oral meperidine is a very weak
opioid, 300 mg = 30 mg oral morphine.
Why is it controversial? Until recently, MP was the most
commonly prescribed drug for post-operative pain, largely by the IM route,
ordered prn at a q4-6 dosing interval. Since physicians largely learned
how to manage pain from their experiences with surgical patients, MP was
the parenteral opioid physicians were most familiar with, ergo, the opioid
they typically used for any severe pain problem. However, due to its
relatively low potency, short duration of action, and toxic metabolite
(see below), MP is a poor analgesic choice.
Over 20 years ago, it became widely recognized that continued MP
administration over several days leads to a syndrome of CNS excitation,
with tremors, myoclonus, delirium, and seizures. This syndrome, due to
accumulation of the metabolite normeperidine, is more prevalent in the
elderly or in patients with renal dysfunction.
Finally, MP was established in medical lore as the drug of
choice for certain pain conditions, notably pancreatitis / biliary colic
and sickle cell pain. In fact, there is little data supporting the
contention that MP is the drug of choice for pancreatitis. A recent review
of opioid effect on biliary pressure found contradictory results from in
vivo biliary manometry studies and only anecdotal reports documenting
significant clinical impact. Recent consensus reports on sickle cell pain
have specifically recommended not using MP, due to its short duration and
toxic metabolite.
What are the recommendations? Every national pain management
Clinical Practice Guideline published since 1990 has advised that
parenteral MP is not appropriate for a) long-term use (beyond several
days), b) any chronic pain syndrome, c) the elderly or d) patients with
renal dysfunction. The American Pain Society recommends ".meperidine
should not be used for more than 48 hours for acute pain in patients
without renal or CNS disease, or at doses greater than 600 mg/24 hours,
and should not be prescribed for chronic pain. In view of all the national
guidelines, some hospitals have removed MP from their formulary, others
restrict use to short-term, procedure related analgesia (e.g. bone marrow
biopsy, colonoscopy).
What is the bottom line? There is little rationale for
prescribing parenteral MP and no justification for using oral MP.
Parenteral MP is a reasonable choice only when a) there is intolerance to
all other opioids and/or b) very brief analgesia is needed.
References:
Principles of Analgesic use in the treatment of acute and cancer
pain. 4th Ed. American Pain Society. 1999; Page 31.
Acute Pain Management Guideline Panel. Acute pain management:
Operative or Medical Procedures and Trauma Clinical Practice Guideline.
AHCPR Publication No. 92-0032. Management of Cancer Pain. Clinical
Practice Guideline No. 9; AHCPR Publication No. 94-0592.Rockville, MD.
Agency for Health Care Policy and Research, US Department of Health and
Human Services, Public Health Service, 1992, 1994.
Cancer pain management in the long-term care setting.
Clinical Practice Guideline, 1999. American Medical Directors
Association.
Simopoulos TT, et al. Use of meperidine in patient-controlled
analgesia and the development of normeperidine toxic reactions.
Archives of Surgery 2002; 137:84-88.
Isenhower HL and Mueller BA. Selection of narcotic analgesics for
pain associated with pancreatitis. Am J Health-Syst Pharm 1998;
55:480-486.
Guideline for the management of acute and chronic pain in sickle
cell disease. American Pain Society, 1999.
