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Drug Interactions between tamoxifen and Xopenex HFA

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

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Interactions between your drugs

Moderate

tamoxifen levalbuterol

Applies to: tamoxifen and Xopenex HFA (levalbuterol)

MONITOR: Beta-2 adrenergic agonists can cause dose-related prolongation of the QT interval and potassium loss. 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. In general, the risk of an individual agent or a combination of agents causing ventricular arrhythmia in association with QT prolongation is largely unpredictable but may be increased by certain underlying risk factors such as congenital long QT syndrome, cardiac disease, and electrolyte disturbances (e.g., hypokalemia, hypomagnesemia). In addition, the extent of drug-induced QT prolongation is dependent on the particular drug(s) involved and dosage(s) of the drug(s). Clinically significant prolongation of QT interval and hypokalemia occur infrequently when beta-2 agonists are inhaled at normally recommended dosages. However, these effects may be more common when the drugs are administered systemically or when recommended dosages are exceeded.

MANAGEMENT: Caution is recommended if beta-2 agonists are used in combination with other drugs that can prolong the QT interval. 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.

References

  1. Whyte KF, Addis GJ, Whitesmith R, Reid JL "The mechanism of salbutamol-induced hypokalaemia." Br J Clin Pharmacol 23 (1987): 65-71
  2. Larsson S, Svedmyr N "Bronchodilating effect and side effects of beta2- adrenoceptor stimulants by different modes of administration (tablets, metered aerosol, and combinations thereof). A study with salbutamol inasthmatics." Am Rev Respir Dis 116 (1977): 861-9
  3. Hastwell G, Lambert BE "The effect of oral salbutamol on serum potassium and blood sugar." Br J Obstet Gynaecol 85 (1978): 767-9
  4. "Hypokalaemia due to salbutamol overdosage." Br Med J (Clin Res Ed) 283 (1981): 500-1
  5. Kantola I, Tarssanen L "Hypokalemia from usual salbutamol dosage ." Chest 89 (1986): 619-20
  6. Wong CS, Pavord ID, Williams J, Britton JR, Tattersfield AE "Bronchodilator, cardiovascular, and hypokalaemic effects of fenoterol, salbutamol, and terbutaline in asthma." Lancet 336 (1990): 1396-9
  7. Gross TL, Sokol RJ "Severe hypokalemia and acidosis: a potential complication of beta- adrenergic treatment." Am J Obstet Gynecol 138 (1980): 1225-6
  8. Clifton GD, Hunt BA, Patel RC, Burki NK "Effects of sequential doses of parenteral terbutaline on plasma levels of potassium and related cardiopulmonary responses." Am Rev Respir Dis 141 (1990): 575-9
  9. Hurlbert BJ, Edelman JD, David K "Serum potassium levels during and after terbutaline." Anesth Analg 60 (1981): 723-5
  10. Bengtsson B, Fagerstrom PO "Extrapulmonary effects of terbutaline during prolonged administration." Clin Pharmacol Ther 31 (1982): 726-32
  11. Gelmont DM, Balmes JR, Yee A "Hypokalemia induced by inhaled bronchodilators." Chest 94 (1988): 763-6
  12. Sanders JP, Potter DE, Ellis S, Bee DE, Grant JA "Metabolic and cardiovascular effects of carbuterol and metaproterenol." J Allergy Clin Immunol 60 (1977): 174-9
  13. "Product Information. Proventil (albuterol)." Schering Corporation PROD (2002):
  14. Windom H, Grainger J, Burgess C, Crane J, Pearce N, Beasley R "A comparison of the haemodynamic and hypokalaemic effects of inhaled pirbuterol and salbutamol." N Z Med J 103 (1990): 259-61
  15. "Product Information. Serevent (salmeterol)." Glaxo Wellcome PROD
  16. "Product Information. Maxair (pirbuterol)." 3M Pharmaceuticals PROD (2001):
  17. Dickens GR, Mccoy RA, West R, Stapczynski JS, Clifton GD "Effect of nebulized albuterol on serum potassium and cardiac rhythm in patients with asthma or chronic obstructive pulmonary disease." Pharmacotherapy 14 (1994): 729-33
  18. Tveskov C, Djurhuus MS, Klitgaard NAH, Egstrup K "Potassium and magnesium distribution, ECG changes, and ventricular ectopic beats during beta(2)-adrenergic stimulation with terbutaline in healthy subjects." Chest 106 (1994): 1654-9
  19. Braden GL, vonOeyen PT, Germain MJ, Watson DJ, Haag BL "Ritodrine- and terbutaline-induced hypokalemia in preterm labor: Mechanisms and consequences." Kidney Int 51 (1997): 1867-75
  20. Rakhmanina NY, Kearns GL, Farrar HC "Hypokalemia in an asthmatic child from abuse of albuterol metered dose inhaler." Pediatr Emerg Care 14 (1998): 145-7
  21. "Product Information. Xopenex (levalbuterol)." Sepracor Inc PROD (2001):
  22. "Product Information. Foradil (formoterol)." Novartis Pharmaceuticals PROD (2001):
  23. Ferguson GT, Funck-Brentano C, Fischer T, Darken P, Reisner C "Cardiovascular Safety of Salmeterol in COPD." Chest 123 (2003): 1817-24
  24. Milic M, Bao X, Rizos D, Liu F, Ziegler MG "Literature review and pilot studies of the effect of qt correction formulas on reported beta(2)-agonist-induced QTc prolongation." Clin Ther 28 (2006): 582-90
  25. "Product Information. Brovana (arformoterol)." Sepracor Inc (2006):
  26. Lowe MD, Rowland E, Brown MJ, Grace AA "Beta(2) adrenergic receptors mediate important electrophysiological effects in human ventricular myocardium." Heart 86 (2001): 45-51
  27. Sun ZH, Swan H, Vitasalo M, Toivonen L "Effects of epinephrine and phenylephrine on QT interval dispersion in congenital long QT syndrome." J Am Coll Cardiol 31 (1998): 1400-5
  28. "Product Information. Arcapta Neohaler (indacaterol)." Novartis Pharmaceuticals (2011):
  29. "Product Information. Breo Ellipta (fluticasone-vilanterol)." GlaxoSmithKline (2013):
  30. "Product Information. Striverdi Respimat (olodaterol)." Boehringer Ingelheim (2014):
View all 30 references

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Drug and food interactions

Moderate

tamoxifen food

Applies to: tamoxifen

GENERALLY AVOID: Due to their estrogenic effect, isoflavones present in soy such as genistein and daidzein may stimulate breast tumor growth and antagonize the antiproliferative action of tamoxifen. Supportive data are derived primarily from in vitro and animal studies. In vitro, low concentrations of these phytoestrogens have been found to promote DNA synthesis and reverse the inhibitory effect of tamoxifen on estrogen-dependent breast cancer cell proliferation. In contrast, high concentrations of genistein greater than 10 microM/L have been found to enhance tamoxifen effects by inhibiting breast cancer cell growth. It is not known if these high concentrations are normally achieved in humans. Plasma concentrations below 4 microM/L have been observed in healthy volunteers given a soy diet for one month or large single doses of genistein. These concentrations are comparable to the low plasma concentrations associated with tumor stimulation reported in animals. In a study of 155 female breast cancer survivors with substantially bothersome hot flashes, a product containing 50 mg of soy isoflavones (40% to 45% genistein; 40% to 45% daidzein; 10% to 20% glycitein) taken three times a day was found to be no more effective than placebo in reducing hot flashes. No toxicity or recurrence of breast cancer was reported during the 9-week study period.

Green tea does not appear to have significant effects on the pharmacokinetics of tamoxifen or its primary active metabolite, endoxifen. In a study consisting of 14 patients who have been receiving tamoxifen treatment at a stable dose of 20 mg (n=13) or 40 mg (n=1) once daily for at least 3 months, coadministration with green tea supplements twice daily for 14 days resulted in no significant differences in the pharmacokinetics of either tamoxifen or endoxifen with respect to peak plasma concentration (Cmax), systemic exposure (AUC), and trough plasma concentration (Cmin) compared to administration of tamoxifen alone. The combination was well tolerated, with all reported adverse events categorized as mild (grade 1) and none categorized as serious or severe (grade 3 or higher) during the entire study. Although some adverse events such as headache, polyuria, gastrointestinal side effects (e.g., constipation, dyspepsia), and minor liver biochemical disturbances were reported more often during concomitant treatment with green tea, most can be attributed to the high dose of green tea used or to the caffeine in green tea. The green tea supplements used were 1000 mg in strength and contained 150 mg of epigallocatechin-3-gallate (EGCG), the most abundant and biologically active catechin in green tea. According to the investigators, the total daily dose of EGCG taken by study participants is equivalent to the amount contained in approximately 5 to 6 cups of regular green tea. However, it is not known to what extent the data from this study may be applicable to other preparations of green tea such as infusions, since the bioavailability of EGCG and other catechins may vary between preparations.

MANAGEMENT: Until more information is available, patients treated with tamoxifen may consider avoiding or limiting the consumption of soy-containing products. Consumption of green tea and green tea extracts during tamoxifen therapy appears to be safe.

References

  1. Therapeutic Research Faculty "Natural Medicines Comprehensive Database. http://www.naturaldatabase.com" (2008):
  2. Braal CL, Hussaarts KGAM, Seuren L, et al. "Influence of green tea consumption on endoxifen steady-state concentration in breast cancer patients treated with tamoxifen." Breast Cancer Res Treat 184 (2020): 107-13

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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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