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Drug Interactions between Invirase and letrozole / ribociclib

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

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Interactions between your drugs

Major

saquinavir ribociclib

Applies to: Invirase (saquinavir) and letrozole / ribociclib

CONTRAINDICATED: Saquinavir in combination with ritonavir 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. In a study of 59 healthy volunteers aged 18 to 55 years who were administered saquinavir/ritonavir at a therapeutic dosage of 1000 mg/100 mg twice daily and a supratherapeutic dosage of 1500 mg/100 mg twice daily, the maximum mean QT prolongation (QTcS; study-specific QT interval correction) on treatment day 3 was 18.9 msec for the lower dosage and 30.2 msec for the supratherapeutic dosage, compared to 12.2 msec for the active control (moxifloxacin 400 mg). The majority of subjects (89% and 80% in the therapeutic and supratherapeutic groups, respectively) had a QTcS less than 450 msec, and none had a QTc interval exceeding the potentially clinically relevant threshold of 500 msec. 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).

MANAGEMENT: Coadministration of ritonavir-boosted saquinavir with other drugs that can prolong the QT interval is considered contraindicated.

References

  1. (2001) "Product Information. Invirase (saquinavir)." Roche Laboratories
  2. Anson BD, Weaver JG, Ackerman MJ, et al. (2005) "Blockade of HERG channels by HIV protease inhibitors." Lancet, 365, p. 682-686
  3. Cerner Multum, Inc. "UK Summary of Product Characteristics."
  4. Canadian Pharmacists Association (2006) e-CPS. http://www.pharmacists.ca/function/Subscriptions/ecps.cfm?link=eCPS_quikLink
  5. Cerner Multum, Inc. "Australian Product Information."
  6. FDA. U.S. Food and Drug Administration (2010) FDA drug safety communication: Ongoing safety review of Invirase (saquinavir) and possible association with abnormal heart rhythms. http://www.fda.gov/Drugs/DrugSafety/PostmarketDrugSafetyInformationforPatientsandProviders/ucm201221.htm
  7. Biondi L (2010) Health Canada endorsed important safety information on Invirase (saquinavir mesylate). http://hc-sc.gc.ca/dhp-mps/alt_formats/pdf/medeff/advisories-avis/prof/2010/invirase_hpc-cps-eng.pdf
View all 7 references

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

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Drug and food interactions

Moderate

saquinavir food

Applies to: Invirase (saquinavir)

ADJUST DOSING INTERVAL: Food significantly increases the absorption of saquinavir.

MONITOR: Coadministration with grapefruit juice may increase the plasma concentrations of saquinavir. The primary mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruits. In eight healthy volunteers, ingestion of 400 mL of grapefruit juice prior to administration of a 600 mg dose of saquinavir mesylate increased the area under the plasma concentration-time curve and oral bioavailability of saquinavir by 50% and 100%, respectively, compared to water; however, the increase is not considered clinically relevant. A high degree of intersubject variability in the grapefruit juice effect was also observed. The extent to which this interaction may occur with the saquinavir free base soft gelatin capsule is unknown. However, the saquinavir soft gelatin capsule formulation is no longer commercially available.

MANAGEMENT: Saquinavir mesylate should be taken with meals or within 2 hours after eating to enhance bioavailability. Patients should be advised to avoid the consumption of large amounts of grapefruit and grapefruit juice during saquinavir therapy unless otherwise directed by their doctor, as the interaction is unreliable and subject to a high degree of interpatient variation.

References

  1. (2001) "Product Information. Invirase (saquinavir)." Roche Laboratories
  2. Kupferschmidt HHT, Fattinger KE, Ha HR, Follath F, Krahenbuhl S (1998) "Grapefruit juice enhances the bioavailability of the HIV protease inhibitor saquinavir in man." Br J Clin Pharmacol, 45, p. 355-9
  3. Bailey DG, Malcolm J, Arnold O, Spence JD (1998) "Grapefruit juice-drug interactions." Br J Clin Pharmacol, 46, p. 101-10
  4. Eagling VA, Profit L, Back DJ (1999) "Inhibition of the CYP3A4-mediated metabolism and P-glycoprotein-mediated transport of the HIV-I protease inhibitor saquinavir by grapefruit juice components." Br J Clin Pharmacol, 48, p. 543-52
  5. Cerner Multum, Inc. "UK Summary of Product Characteristics."
  6. Cerner Multum, Inc. "Australian Product Information."
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. (2017) "Product Information. Kisqali (ribociclib)." Novartis Pharmaceuticals

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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.

Further information

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