What Is Erlotinib?

Erlotinib, also known as Tarceva, is a targeted cancer drug used to treat metastatic non-small cell lung cancer (NSCLC) in patients with a specific gene mutation (EGFR exon 19 deletion or exon 21 [L858R] substitution mutations) as first-line therapy, maintenance treatment, or for progressive disease.  It is also used to treat patients with locally advanced, unresectable, or metastatic pancreatic cancer. Lastly, it can be used for advanced papillary kidney cancer (off-label use).

د عمل میکانیزم

Erlotinib is a tyrosine kinase inhibitor (TKI), a type of cancer growth blocker. Its mechanism of action is to block proteins on cancer cells that encourage them to grow. These proteins are called epidermal growth factor receptors (EGFR). It has been shown to be effective in patients whose cancer cells express the EGFR mutations, even though it can also be utilized in patients whose tumor cells do not express these mutations.

Drug Interactions

The blood level of this medication is affected by certain foods and medications. Therefore, the following should be avoided or a dose reduction should be considered if severe adverse reactions occur:

• Atazanavir
• Clarithromycin
• Indinavir
• Itraconazole
• Ketoconazole
• Nefazodone
• Nelfinavir
• Ritonavir
• Saquinavir
• Telithromycin
• Troleandomycin (TAO)
• Voriconazole
• Grapefruit or grapefruit juice.

Cigarette smoking can reduce erlotinib levels. Patients should therefore stop smoking while taking this medication. However, if they continue to smoke, a cautious increase in dose may be considered.

Drugs that alter the pH of the upper GI tract may alter the solubility of erlotinib and reduce its effects. Coadministration of erlotinib with omeprazole (a proton pump inhibitor) can decrease erlotinib’s concentration so this combination should be avoided if possible. If patients need to be treated with a H2-receptor antagonist (i.e., ranitidine), erlotinib must be taken once a day, 10 hours after the H2-receptor antagonist dosing, and at least 2 hours before the next dose of the H2-receptor antagonist. Although the effect of antacids on erlotinib has not been evaluated, the antacid and erlotinib use should be separated by several hours, if an antacid is necessary.