Pharmacology of morphine in obese patients: clinical implications.
Morphine is an analgesic drug used to treat acute and chronic pain. Obesity is frequently associated with pain of various origins (e.g. arthritis, fibromyalgia, cancer), which increases the need for analgesic drugs. Obesity changes drug pharmacokinetics, and for certain drugs, specific modalities of prescription have been proposed for obese patients. However, scant data are available regarding the pharmacokinetics and pharmacodynamics of morphine in obesity. Prescription of morphine depends on pain relief but the occurrence of respiratory adverse effects correlates with obesity, and is not currently taken into account. Variations in the volume of distribution, elimination half-life and oral clearance of morphine, as well as recent advances in the respective roles of drug-metabolizing enzymes, catechol-O-methyltransferase and the mu opioid receptor in morphine pharmacokinetics and pharmacodynamics, may contribute to differences between obese and non-obese patients. In addition, drug-drug interactions may alter the disposition of morphine and its glucuronide metabolites, which may either increase the risk of adverse effects or reduce drug efficacy.
Lloret Linares
Célia
C
Unit of Therapeutic Research, Department of Internal Medicine, Hôpital Lariboisière, Assistance Publique-Hôpitaux de Paris, Paris, France.
Declèves
Xavier
X
Oppert
Jean Michel
JM
Basdevant
Arnaud
A
Clement
Karine
K
Bardin
Christophe
C
Scherrmann
Jean Michel
JM
Lepine
Jean Pierre
JP
Bergmann
Jean François
JF
Mouly
Stéphane
S
D000700:Analgesics / Q000493:pharmacokinetics; D006801:Humans; D009020:Morphine / Q000378:metabolism / Q000493:pharmacokinetics*; D009765:Obesity / Q000150:complications / Q000188:drug therapy*; D010146:Pain / Q000188:drug therapy / Q000209:etiology; D010599:Pharmacokinetics
D000700:Analgesics; D009020:Morphine