Morphine is widely used in critical care. Glucuronidation of morphine produces two metabolites, morphine-3-glucuronide and morphine-6-glucuronide.

The concentrations of morphine-3-glucuronide and morphine-6-glucuronide may be up to 10 times and 100 times respectively the concentration of morphine in the plasma. Morphine-3-glucuronide tends to antagonize morphine, and morphine-6-glucuronide is up to 10 times more effective than morphine in tests of analgesia. The metabolites depend on glomerular filtration and accumulate in renal failure. This is a significant drawback in critical care patients as it may result in prolonged weaning, increased morbidity, and increased costs. Multicompartmental pharmacokinetic data are not available for morphine. Following titration (front-loading), the elimination half-life (approximately 3 h) is used to calculate the approximate infusion rate as the dose of morphine required in a 3-h period is half the front-loading dose. Suboptimal analgesia requires retitration as adjustment of the infusion alone requires four to five half-lives to steady state.

Sleep Apnea

Sleep Apnea

Have You Been Told Over And Over Again That You Snore A Lot, But You Choose To Ignore It? Have you been experiencing lack of sleep at night and find yourself waking up in the wee hours of the morning to find yourself gasping for air?

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