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Drug Interactions between Fensolvi and methadone

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

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Major

methadone leuprolide

Applies to: methadone and Fensolvi (leuprolide)

MONITOR CLOSELY: Methadone may cause dose-related prolongation of the QT interval. Theoretically, coadministration with other agents that can prolong the QT interval may result in additive effects and increased risk of ventricular arrhythmias including torsade de pointes and sudden death. High dosages of methadone alone have been associated with QT interval prolongation and torsade de pointes. In a retrospective study of 17 methadone-treated patients who developed torsade de pointes, the mean daily dose was approximately 400 mg (range 65 to 1000 mg) and the mean corrected QT (QTc) interval on presentation was 615 msec. The daily methadone dose correlated positively with the QTc interval. Fourteen patients had at least one predisposing risk factor for arrhythmia (hypokalemia, hypomagnesemia, concomitant use of a medication known to prolong the QT interval or inhibit the metabolism of methadone, and structural heart disease), but these were not predictive of QTc interval. It is not known if any of the patients had congenital long QT syndrome.

MANAGEMENT: Caution is recommended if methadone is used in combination with other drugs that can prolong the QT interval, particularly in the setting of chronic pain management or methadone maintenance for opioid dependency where high dosages may be employed. Patients should be advised to seek prompt medical attention if they experience symptoms that could indicate the occurrence of torsade de pointes such as dizziness, lightheadedness, fainting, palpitation, irregular heart rhythm, shortness of breath, or syncope. If taking drugs that also cause CNS-depressant or orthostatic effects (e.g., sedating antihistamines, psychotropic drugs like tricyclic antidepressants, phenothiazines, and neuroleptics), patients should be made aware of the possibility of additive effects with methadone and counseled to avoid activities requiring mental alertness until they know how these agents affect them.

References

  1. Krantz MJ, Lewkowiez L, Hays H, et al. (2002) "Torsade de pointes associated with very-high-dose methadone." Ann Intern Med, 137, p. 501-4
  2. Walker PW, Klein D, Kasza L (2003) "High dose methadone and ventricular arrhythmias: a report of three cases." Pain, 103, p. 321-4
  3. Krantz MJ, Kutinsky IB, Robertson AD, Mehler PS (2003) "Dose-related effects of methadone on QT prolongation in a series of patients with torsade de pointes." Pharmacotherapy, 23, p. 802-5
  4. De Bels D, Staroukine M, Devriendt J (2003) "Torsades de pointes due to methadone." Ann Intern Med, 139, E156
  5. Krantz MJ, Mehler PS (2003) "Synthetic opioids and QT prolongation." Arch Intern Med, 163, 1615; author reply 1615
  6. Sala M, Anguera I, Cervantes M (2003) "Torsade de pointes due to methadone." Ann Intern Med, 139, W64
  7. Mokwe EO, Ositadinma O (2003) "Torsade de pointes due to methadone." Ann Intern Med, 139, W64
  8. Gil M, Sala M, Anguera I, et al. (2003) "QT prolongation and Torsades de Pointes in patients infected with human immunodeficiency virus and treated with methadone." Am J Cardiol, 92, p. 995-7
  9. Martell BA, Arnsten JH, Krantz MJ, Gourevitch MN (2005) "Impact of methadone treatment on cardiac repolarization and conduction in opioid users." Am J Cardiol, 95, p. 915-8
  10. Cerner Multum, Inc. "UK Summary of Product Characteristics."
  11. Canadian Pharmacists Association (2006) e-CPS. http://www.pharmacists.ca/function/Subscriptions/ecps.cfm?link=eCPS_quikLink
  12. Ehret GB, Desmeules JA, Broers B (2007) "Methadone-associated long QT syndrome: improving pharmacotherapy for dependence on illegal opioids and lessons learned for pharmacology." Expert Opin Drug Saf, 6, p. 289-303
  13. Cerner Multum, Inc. "Australian Product Information."
  14. EMA. European Medicines Agency. European Union (2013) EMA - List of medicines under additional monitoring. http://www.ema.europa.eu/ema/index.jsp?curl=pages/regulation/document_listing/document_listing_000366.jsp&mid=WC0b01ac058067c852
View all 14 references

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Drug and food interactions

Moderate

methadone food

Applies to: methadone

GENERALLY AVOID: Coadministration with grapefruit juice may increase the plasma concentrations of methadone. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruits. In 8 study subjects stabilized on methadone maintenance treatment, ingestion of regular strength grapefruit juice (200 mL one-half hour before and 200 mL simultaneously with the daily methadone dose) for five days resulted in an approximately 17% mean increase in methadone peak plasma concentration (Cmax) and systemic exposure (AUC) and a 14% mean decrease in apparent clearance for both the R(+) and S(-) enantiomers. Grapefruit juice did not affect the time to peak level (Tmax), terminal half-life, or apparent volume of distribution of methadone. No signs or symptoms of methadone toxicity or changes in intensity of withdrawal symptoms were reported in the study.

MANAGEMENT: Given the interindividual variability in the pharmacokinetics of methadone, a more significant interaction with grapefruit juice in certain patients cannot be ruled out. Patients treated with methadone should preferably avoid or limit the consumption of grapefruit juice, particularly during the induction of maintenance treatment.

References

  1. Iribarne C, Berthou F, Baird S, Dreano Y, Picart D, Bail JP, Beaune P, Menez JF (1996) "Involvement of cytochrome P450 3A4 enzyme in the N-demethylation of methadone in human liver microsomes." Chem Res Toxicol, 9, p. 365-73
  2. Oda Y, Kharasch ED (2001) "Metabolism of methadone and levo-alpha-acetylmethadol (LAAM) by human intestinal cytochrome P450 3A4 (CYP3A4): potential contribution of intestinal metabolism to presystemic clearance and bioactivation." J Pharmacol Exp Ther, 298, p. 1021-32
  3. Benmebarek M, Devaud C, Gex-Fabry M, et al. (2004) "Effects of grapefruit juice on the pharmacokinetics of the enantiomers of methadone." Clin Pharmacol Ther, 76, p. 55-63
  4. Foster DJ, Somogyi AA, Bochner F (1999) "Methadone N-demethylation in human liver microsomes: lack of stereoselectivity and involvement of CYP3A4." Br J Clin Pharmacol, 47, p. 403-12
View all 4 references

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Moderate

methadone food

Applies to: methadone

GENERALLY AVOID: Ethanol may potentiate the central nervous system (CNS) depressant effects of opioid analgesics. 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.

MANAGEMENT: Concomitant use of opioid analgesics with ethanol should be avoided.

References

  1. Linnoila M, Hakkinen S (1974) "Effects of diazepam and codeine, alone and in combination with alcohol, on simulated driving." Clin Pharmacol Ther, 15, p. 368-73
  2. Sturner WQ, Garriott JC (1973) "Deaths involving propoxyphene: a study of 41 cases over a two-year period." JAMA, 223, p. 1125-30
  3. Girre C, Hirschhorn M, Bertaux L, et al. (1991) "Enhancement of propoxyphene bioavailability by ethanol: relation to psychomotor and cognitive function in healthy volunteers." Eur J Clin Pharmacol, 41, p. 147-52
  4. Levine B, Saady J, Fierro M, Valentour J (1984) "A hydromorphone and ethanol fatality." J Forensic Sci, 29, p. 655-9
  5. Sellers EM, Hamilton CA, Kaplan HL, Degani NC, Foltz RL (1985) "Pharmacokinetic interaction of propoxyphene with ethanol." Br J Clin Pharmacol, 19, p. 398-401
  6. Carson DJ (1977) "Fatal dextropropoxyphene poisoning in Northern Ireland. Review of 30 cases." Lancet, 1, p. 894-7
  7. Rosser WW (1980) "The interaction of propoxyphene with other drugs." Can Med Assoc J, 122, p. 149-50
  8. Edwards C, Gard PR, Handley SL, Hunter M, Whittington RM (1982) "Distalgesic and ethanol-impaired function." Lancet, 2, p. 384
  9. Kiplinger GF, Sokol G, Rodda BE (1974) "Effect of combined alcohol and propoxyphene on human performance." Arch Int Pharmacodyn Ther, 212, p. 175-80
View all 9 references

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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.

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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.

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