With which drugs is erlotinib contraindicated?

Erlotinib, as an anti-lung cancer targeted drug, is contraindicated in combination with a variety of drugs.

1.CYP3A4Strong inhibitors or combined CYP3A4/CYP1A2inhibitors:

Including drugs such as ketoconazole, ciprofloxacin, and fluvoxamine. These drugs may increase the plasma concentration of erlotinib, leading to increased adverse reactions. Therefore, care should be taken during combined use and if toxic effects are detected, the dose of erlotinib should be reduced.

2.CYP3A4Strong inducer:

For example, rifampicin can increase the metabolism of erlotinib, significantly reduce the plasma concentration of erlotinib, and affect the efficacy. If possible, other drug treatment that is not a strong inducer of CYP3A4 should be chosen. For patients requiring treatment with erlotinib in combination with strong CYP3A4 inducers, dose adjustments should be considered with close monitoring of drug safety.

3.Other drugs that may reduce erlotinib exposure:

Including phenytoin, carbamazepine, barbiturates or St. John's wort, etc. These drugs may reduce erlotinib exposure and affect efficacy. Caution should be exercised during combined use, and where possible, the use of other therapeutic drugs without potent CYP3A4 inducing activity should be considered when possible.

4.Drugs that change the pH value of the upper gastrointestinal tract:

Such as proton pump inhibitors (such as omeprazole) andH2Receptor blocking drugs (such as ranitidine). These drugs may alter the solubility of erlotinib and thus affect its bioavailability. Therefore, concomitant use of erlotinib with drugs that reduce gastric acid production should be avoided. If patients need to receive such drug treatment, the administration time should be reasonably arranged to ensure that the absorption of erlotinib is not affected.

5.P-glycoprotein (Pgp) inhibitor:

Such as cyclosporine and verapamil. Erlotinib is a substrate of the P-glycoprotein active substrate transporter, and coadministration with Pgp inhibitors may alter the distribution and /or elimination of erlotinib. The impact of this interaction on toxicity is currently unknown and caution should be used in this setting.

6.Other drugs that may increase adverse reactions:

Like statins, coadministration with erlotinib may increase the incidence of statin-induced myopathies including the rare form of rhabdomyolysis. Therefore, the combined use of erlotinib and statins should be avoided as much as possible.

In addition, although erlotinib has no significant effect on the pharmacokinetics of erlotinib when combined with certain chemotherapy drugs such as carboplatin and paclitaxel, there may be other common factors that lead to an increase in adverse reactions in clinical practice. Therefore, patient response should be closely monitored when used in combination.