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Drug Interactions between cimetidine and Morphine Sulfate ER

This report displays the potential drug interactions for the following 2 drugs:

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Interactions between your drugs

Moderate

cimetidine morphine

Applies to: cimetidine and Morphine Sulfate ER (morphine)

MONITOR: Cimetidine may increase the effects of narcotic analgesics. Cases of respiratory depression, potentially fatal, have been reported in patients receiving cimetidine with morphine. The mechanism is unclear but may be related to decreased metabolism of the opioid. A similar interaction may also occur with diamorphine, for which morphine is the primary active metabolite.

MANAGEMENT: Patients' vital signs should be closely monitored while receiving this combination. If respiratory depression is greater than otherwise expected, consider decreasing the dose of the opioid and/or of cimetidine as necessary.

References

  1. Lam AM, Clement JL "Effect of cimetidine premedication on morphine-induced ventilatory depression." Can Anaesth Soc J 31 (1984): 36-43
  2. Fine A, Churchill DN "Potentially lethal interaction of cimetidine and morphine." Can Med Assoc J 124 (1981): 1434, 1436
  3. Lam AM "Potentially lethal interaction of cimetidine and morphine." Can Med Assoc J 125 (1981): 820
  4. "Product Information. MS Contin (morphine)." Purdue Frederick Company PROD (2002):
  5. "Product Information. Morphine Sulfate (morphine)." Abbott Pharmaceutical PROD
  6. Cerner Multum, Inc. "Canadian Product Information." O 0 (2015):
View all 6 references

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Drug and food interactions

Major

morphine food

Applies to: Morphine Sulfate ER (morphine)

GENERALLY AVOID: Alcohol may potentiate the central nervous system (CNS) depressant effects of opioid analgesics including morphine and diamorphine. Concomitant use may result in additive CNS depression and impairment of judgment, thinking, and psychomotor skills. In more severe cases, hypotension, respiratory depression, profound sedation, coma, or even death may occur.

GENERALLY AVOID: Consumption of alcohol while taking some sustained-release formulations of morphine may cause rapid release of the drug, resulting in high systemic levels of morphine that may be potentially lethal. Alcohol apparently can disrupt the release mechanism of some sustained-release formulations. The interaction was observed in in vitro studies using a 24-hour morphine formulation (Avinza 30 mg capsule, available in the U.S. from Ligand Pharmaceuticals). When the capsule was mixed with 900 mL of buffer solutions containing ethanol 20% and 40%, the dose of morphine that was released was alcohol concentration-dependent, leading to a more rapid release of morphine. Although the clinical relevance of this finding is unknown, 'dose-dumping' into the bloodstream is conceivable.

MANAGEMENT: Until more information is available, patients taking sustained-release formulations of morphine should not consume alcohol or use medications that contain alcohol. In general, potent narcotics such as morphine or diamorphine should not be combined with alcohol.

References

  1. "Product Information. Avinza (morphine)." Ligand Pharmaceuticals (2005):
  2. Ghalie R "Dear Health Care Professional. http://www.fda.gov/medwatch/safety/2005/AVINZA_DHCP_Letter_Oct2005.pdf" (2005):
  3. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
  4. Cerner Multum, Inc. "Canadian Product Information." O 0 (2015):
View all 4 references

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Minor

cimetidine food

Applies to: cimetidine

Concurrent use of cimetidine and ethanol may result in increased ethanol concentrations. The mechanism appears to be due to inhibition of gastric alcohol dehydrogenase by cimetidine, leading to increased bioavailability of the alcohol and inhibition of hepatic metabolism of alcohol. The clinical significance of this interaction is limited. More importantly, patients requiring cimetidine for gastrointestinal disease should be counseled to avoid alcohol to prevent worsening of their disease. The other H-2 receptor antagonists appear to have minimal effects on the concentrations of alcohol.

References

  1. Feely J, Wood AJ "Effects of cimetidine on the elimination and actions of ethanol." JAMA 247 (1982): 2819-21
  2. Hansten PD "Effects of H2-receptor antagonists on blood alcohol levels." JAMA 267 (1992): 2469

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Minor

cimetidine food

Applies to: cimetidine

Caffeine effects may be increased in patients also taking cimetidine. The mechanism may be due to decreased caffeine metabolism induced by cimetidine. Although adequate clinical data are lacking, a reduction in dose or elimination of caffeine may be needed if excess CNS stimulation is observed.

References

  1. "Product Information. Tagamet (cimetidine)." SmithKline Beecham PROD (2001):
  2. Broughton LJ, Rodgers HJ "Decreased systenuc clearance of caffeine due to cimetidine." Br J Clin Pharmacol 12 (1981): 155-9

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Minor

cimetidine food

Applies to: cimetidine

H2 antagonists may reduce the clearance of nicotine. Cimetidine, 600 mg given twice a day for two days, reduced clearance of an intravenous nicotine dose by 30%. Ranitidine, 300 mg given twice a day for two days, reduced clearance by 10%. The clinical significance of this interaction is not known. Patients should be monitored for increased nicotine effects when using the patches or gum for smoking cessation and dosage adjustments should be made as appropriate.

References

  1. Bendayan R, Sullivan JT, Shaw C, Frecker RC, Sellers EM "Effect of cimetidine and ranitidine on the hepatic and renal elimination of nicotine in humans." Eur J Clin Pharmacol 38 (1990): 165-9

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Therapeutic duplication warnings

No warnings were found for your selected drugs.

Therapeutic duplication warnings are only returned when drugs within the same group exceed the recommended therapeutic duplication maximum.

See also

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Drug Interaction Classification

These classifications are only a guideline. The relevance of a particular drug interaction to a specific individual is difficult to determine. Always consult your healthcare provider before starting or stopping any medication.
Major Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit.
Moderate Moderately clinically significant. Usually avoid combinations; use it only under special circumstances.
Minor Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan.
Unknown No interaction information available.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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