Afinitor Drug Interactions

Everolimus is a substrate of CYP3A4, and also a substrate and moderate inhibitor of PgP. Therefore, absorption and subsequent elimination of everolimus may be influenced by products that affect CYP3A4 and/or PgP. In vitro, everolimus is a competitive inhibitor of CYP3A4 and a mixed inhibitor of CYP2D6.
Known and theoretical interactions with selected inhibitors and inducers of CYP3A4 and PgP are listed in Tables 16, 17 and 18 as follows.
CYP3A4 and PgP inhibitors increasing everolimus concentrations: Substances that are inhibitors of CYP3A4 or PgP may increase everolimus blood concentrations by decreasing metabolism or the efflux of everolimus from intestinal cells.
CYP3A4 and PgP inducers decreasing everolimus concentrations: Substances that are inducers of CYP3A4 or PgP may decrease everolimus blood concentrations by increasing metabolism or the efflux of everolimus from intestinal cells.
Tablet (Oncology Indications): See Table 16.

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Tablet (Tuberous Sclerosis Complex-Related Indications): See Table 17.

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Dispersible tablet: See Table 18.

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Agents whose plasma concentration may be altered by everolimus: Based on in vitro results, the systemic concentrations obtained after oral daily doses of 10 mg make inhibition of PgP, CYP3A4 and CYP2D6 unlikely. However, inhibition of CYP3A4 and PgP in the gut cannot be excluded. An interaction study in healthy subjects demonstrated that co-administration of an oral dose of midazolam, a sensitive CYP3A substrate probe, with everolimus resulted in a 25% increase in midazolam C_max and a 30% increase in midazolam AUC_(0-inf). The effect is likely to be due to inhibition of intestinal CYP3A4 by everolimus. Hence everolimus may affect the bioavailability of orally co-administered CYP3A4 substrates. However, a clinically relevant effect on the exposure of systemically administered CYP3A4 substrates is not expected (see Precautions).
Tablet (Tuberous Sclerosis Complex-Related Indications) and Dispersible tablet: In EXIST-3 (Study CRAD001M2304), everolimus increased pre-dose concentrations of the antiepileptics carbamazepine, clobazam, and the clobazam metabolite N-desmethylclobazam by about 10%. The increase in the pre-dose concentrations of these antiepileptics may not be clinically significant but dose adjustments for antiepileptics with a narrow therapeutic index, e.g carbamazepine, may be considered. Everolimus had no impact on pre-dose concentrations of antiepileptics that are substrates of CYP3A4 (clonazepam, diazepam, felbamate and zonisamide).
Tablet (Oncology Indications): Co-administration of everolimus and depot octreotide increased octreotide C_min with a geometric mean ratio (everolimus/placebo) of 1.47. A clinically significant effect on the efficacy response to everolimus in patients with advanced neuroendocrine tumours could not be established.
Co-administration of everolimus and exemestane increased exemestane C_min and C_2h by 45% and 64%, respectively. However, the corresponding oestradiol levels at steady state (4 weeks) were not different between the two treatment arms. No increase in adverse reactions related to exemestane was observed in patients with hormone receptor-positive advanced breast cancer receiving the combination. The increase in exemestane levels is unlikely to have an impact on efficacy or safety.
Concomitant use of angiotensin-converting enzyme (ACE) inhibitors: Patients taking concomitant ACE inhibitor (e.g. ramipril) therapy may be at increased risk for angioedema (see Precautions).
Concomitant ketogenic diet (Dispersible tablet only): The effect of a ketogenic diet may be mediated through mTOR inhibition. In the absence of clinical data, the possibility of an additive effect on adverse events cannot be excluded when everolimus is given in conjunction with a ketogenic diet.
Vaccinations: The immune response to vaccination may be affected and, therefore, vaccination may be less effective during treatment with Afinitor. The use of live vaccines should be avoided during treatment with Afinitor (see Precautions). Examples of live vaccines are: intranasal influenza, measles, mumps, rubella, oral polio, BCG (Bacillus Calmette-Guérin), yellow fever, varicella, and TY21a typhoid vaccines.
Radiation treatment: Potentiation of radiation treatment toxicity has been reported in patients receiving everolimus (see Precautions and Adverse Reactions).