Know the Characteristics of the Narcotics You Prescribe

Know the Characteristics of the Narcotics You Prescribe

Nirav G. Shah MD

Pain control is an important aspect of critical care medicine and the use of opiate medications has typically been an important method of achieving control in the intensive care unit (ICU) setting. The brain has four opiate receptors that include the mu, kappa, delta, and sigma receptors. Currently used opioid analgesics bind to the mu receptor and initiate the pharmacological effects of analgesia, miosis, respiratory depression, euphoria, and physical dependence.

The route of opiate administration is often intravenous, with bolus administration for mild to moderate pain, continuous infusion for moderate to severe pain, and patient-controlled analgesia for the post-surgical patient who can participate in his or her care. Like other ICU interventions where benefits must be balanced against risks, adequate analgesia must carefully be balanced with the side effects of opiate therapy, particularly in the critically ill patient. These include respiratory depression, hypotension, emesis, flushing, bronchospasm, and constipation.

What to Do

The three most commonly prescribed analgesics in the ICU are morphine, hydromorphone, and fentanyl. While morphine is widely used in the ICU setting, fentanyl has additional benefits for the critically ill patient because of its increased potency, lipid solubility, and hemodynamic stability. Morphine dosing usually begins at 2 mg and is then titrated up by 1 mg to 2 mg every few hours if given in intermittent bolus form and 1 mg/hour if given continuously. Morphine metabolism occurs in the liver with excretion occurring in the kidney. Therefore, the dose should be reduced if the patient has a glomerular filtration rate less than 30 mL/min in order to prevent accumulation of its active metabolite.

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Jul 1, 2016 | Posted by in ANESTHESIA | Comments Off on Know the Characteristics of the Narcotics You Prescribe

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