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Drug Interactions between letrozole / ribociclib and Rifadin

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

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Interactions between your drugs

Major

rifAMPin ribociclib

Applies to: Rifadin (rifampin) and letrozole / ribociclib

GENERALLY AVOID: Coadministration with potent CYP450 3A4 inducers may significantly decrease the plasma concentrations and therapeutic effects of ribociclib, which is a substrate of the isoenzyme. In healthy study subjects, administration of a single 600 mg dose of ribociclib with multiple 600 mg daily doses of rifampin, a potent CYP450 3A4 inducer, resulted in an 81% and 89% decrease in ribociclib peak plasma concentration (Cmax) and systemic exposure (AUC), respectively, compared to ribociclib administered alone. In addition, administration of efavirenz, a moderate CYP450 3A4 inducer, is predicted to decrease ribociclib Cmax and AUC by 37% and 60%, respectively.

MANAGEMENT: Concomitant use of ribociclib with potent CYP450 3A4 inducers should generally be avoided. Alternative agents with no or minimal CYP450 3A4 induction potential are recommended whenever possible. If coadministration is necessary, dosage adjustments as well as clinical and laboratory monitoring should be considered whenever a potent CYP450 3A4 inducer is added to or withdrawn from therapy. Patients should be monitored for therapeutic failure.

References

  1. "Product Information. Kisqali (ribociclib)." Novartis Pharmaceuticals (2017):

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Moderate

letrozole ribociclib

Applies to: letrozole / ribociclib and letrozole / ribociclib

MONITOR: Coadministration with ribociclib may increase the plasma concentrations and pharmacologic effects of drugs that are substrates of CYP450 3A4. The proposed mechanism is decreased clearance due to ribociclib-mediated inhibition of CYP450 3A4 metabolism. In healthy study subjects, administration of midazolam, a sensitive CYP450 3A4 substrate, with multiple 400 mg daily doses of ribociclib increased the midazolam peak plasma concentration (Cmax) and systemic exposure (AUC) by 2.1-fold and 3.8-fold, respectively, compared to midazolam administered alone. When given at a clinically relevant dose of 600 mg daily, ribociclib is predicted to increase midazolam Cmax and AUC by 2.4-fold and 5.2-fold, respectively.

MANAGEMENT: Caution is advised when ribociclib is used concomitantly with drugs that undergo metabolism by CYP450 3A4, particularly those with a narrow therapeutic range. Dosage adjustments as well as clinical and laboratory monitoring may be appropriate for some drugs whenever ribociclib is added to or withdrawn from therapy.

References

  1. Zhou XJ, Zhou-Pan XR, Gauthier T, Placidi M, Maurel P, Rahmani R "Human liver microsomal cytochrome P450 3A isozymes mediated vindesine biotransformation. Metabolic drug interactions." Biochem Pharmacol 45 (1993): 853-61
  2. Trivier JM, Libersa C, Belloc C, Lhermitte M "Amiodarone N-deethylation in human liver microsomes: involvement of cytochrome P450 3A enzymes (first report)." Life Sci 52 (1993): pl91-6
  3. Rawden HC, Kokwaro GO, Ward SA, Edwards G "Relative contribution of cytochromes P-450 and flavin-containing monoxygenases to the metabolism of albendazole by human liver microsomes." Br J Clin Pharmacol 49 (2000): 313-22
  4. DSouza DL, Levasseur LM, Nezamis J, Robbins DK, Simms L, Koch KM "Effect of alosetron on the pharmacokinetics of alprazolam." J Clin Pharmacol 41 (2001): 452-4
  5. Katoh M, Nakajima M, Yamazaki H, Yokoi T "Inhibitory effects of CYP3A4 substrates and their metabolites on P-glycoprotein-mediated transport." Eur J Pharm Sci 12 (2001): 505-13
  6. Kane GC, Lipsky JJ "Drug-grapefruit juice interactions." Mayo Clin Proc 75 (2000): 933-42
  7. Yu DK "The contribution of P-glycoprotein to pharmacokinetic drug-drug interactions." J Clin Pharmacol 39 (1999): 1203-11
  8. Nagy J, Schipper HG, Koopmans RP, Butter JJ, van Boxtel CJ, Kager PA "Effect of grapefruit juice or cimetidine coadministration on albendazole bioavailability." Am J Trop Med Hyg 66 (2002): 260-3
  9. "Product Information. Kisqali (ribociclib)." Novartis Pharmaceuticals (2017):
View all 9 references

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Drug and food interactions

Moderate

rifAMPin food

Applies to: Rifadin (rifampin)

GENERALLY AVOID: Concurrent use of rifampin in patients who ingest alcohol daily may result in an increased incidence of hepatotoxicity. The increase in hepatotoxicity may be due to an additive risk as both alcohol and rifampin are individually associated with this adverse reaction. However, the exact mechanism has not been established.

ADJUST DOSING INTERVAL: Administration with food may reduce oral rifampin absorption, increasing the risk of therapeutic failure or resistance. In a randomized, four-period crossover phase I study of 14 healthy male and female volunteers, the pharmacokinetics of single dose rifampin 600 mg were evaluated under fasting conditions and with a high-fat meal. Researchers observed that administration of rifampin with a high-fat meal reduced rifampin peak plasma concentration (Cmax) by 36%, nearly doubled the time to reach peak plasma concentration (Tmax) but reduced overall exposure (AUC) by only 6%.

MANAGEMENT: The manufacturer of oral forms of rifampin recommends administration on an empty stomach, 30 minutes before or 2 hours after meals. Patients should be encouraged to avoid alcohol or strictly limit their intake. Patients who use alcohol and rifampin concurrently or have a history of alcohol use disorder may require additional monitoring of their liver function during treatment with rifampin.

References

  1. "Product Information. Rifampin (rifAMPin)." Akorn Inc (2022):
  2. "Product Information. Rifampicin (rifampicin)." Mylan Pharmaceuticals Inc (2022):
  3. "Product Information. Rifadin (rifampicin)." Sanofi (2023):
  4. "Product Information. Rifadin (rifaMPICin)." Sanofi-Aventis Australia Pty Ltd (2024):
  5. Peloquin CA, Namdar R, Singleton MD, Nix DE "Pharmacokinetics of rifampin under fasting conditions, with food, and with antacids https://pubmed.ncbi.nlm.nih.gov/9925057/" (2024):
  6. "Product Information. Rofact (rifampin)." Bausch Health, Canada Inc. (2019):
View all 6 references

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Moderate

ribociclib food

Applies to: letrozole / ribociclib

GENERALLY AVOID: Pomegranates and grapefruit may increase the systemic exposure to ribociclib. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in these fruits. Increased exposure to ribociclib may increase the risk of adverse effects such as infections, neutropenia, leukopenia, anemia, thrombocytopenia, anorexia, nausea, vomiting, diarrhea, stomatitis, alopecia, fatigue, headache, and abnormal liver function may be increased.

MANAGEMENT: Patients receiving ribociclib should avoid consumption of pomegranates or pomegranate juice and grapefruit or grapefruit juice during treatment.

References

  1. "Product Information. Kisqali (ribociclib)." Novartis Pharmaceuticals (2017):

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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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