INTERACTIONS CYP3A4 Inhibitors Co-administration of erlotinib tablets with a strong CYP3A4 inhibitor or a combined CYP3A4 and CYP1A2 inhibitor increased erlotinib exposure. Erlotinib is metabolized primarily by CYP3A4 and to a lesser extent by CYP1A2. Increased erlotinib exposure may increase the risk of exposure-related toxicity [see Clinical Pharmacology (12.3) ] . Avoid co-administering erlotinib tablets with strong CYP3A4 inhibitors (e.g., boceprevir, clarithromycin, conivaptan, indinavir, itraconazole, ketoconazole, lopinavir/ritonavir, nefazodone, nelfinavir, posaconazole, ritonavir, saquinavir, telithromycin, voriconazole, grapefruit or grapefruit juice) or a combined CYP3A4 and CYP1A2 inhibitor (e.g., ciprofloxacin). Reduce the erlotinib tablets dosage when co-administering with a strong CYP3A4 inhibitor or a combined CYP3A4 and CYP1A2 inhibitor if co-administration is unavoidable [see Dosage and Administration (2.4) ] . CYP3A4 Inducers Pre-treatment with a CYP3A4 inducer prior to erlotinib tablets decreased erlotinib exposure [see Clinical Pharmacology (12.3) ] . Increase the erlotinib tablets dosage if co-administration with CYP3A4 inducers (e.g., carbamazepine, phenytoin, rifampin, rifabutin, rifapentine, phenobarbital and St. John's wort) is unavoidable [see Dosage and Administration (2.4) ]. CYP1A2 Inducers and Cigarette Smoking Cigarette smoking decreased erlotinib exposure. Avoid smoking tobacco (CYP1A2 inducer) and avoid concomitant use of erlotinib tablets with moderate CYP1A2 inducers (e.g., teriflunomide, rifampin, or phenytoin). Increase the erlotinib tablets dosage in patients that smoke tobacco or when co-administration with moderate CYP1A2 inducers is unavoidable [see Dosage and Administration (2.4) and Clinical Pharmacology (12.3) ] . Drugs the Increase Gastric pH Co-administration of erlotinib tablets with proton pump inhibitors (e.g., omeprazole) and H-2 receptor antagonists (e.g., ranitidine) decreased erlotinib exposure [see Clinical Pharmacology (12.3) ] . For proton pump inhibitors, avoid concomitant use if possible. For H-2 receptor antagonists and antacids, modify the dosing schedule [see Dosage and Administration (2.4) ]. Increasing the dose of erlotinib when co-administered with gastric PH elevating agents is not likely to compensate for the loss of exposure.
Anticoagulants
Interaction with coumarin-derived anticoagulants, including warfarin, leading to increased International Normalized Ratio (INR) and bleeding adverse reactions, which in some cases were fatal, have been reported in patients receiving erlotinib tablets. Regularly monitor prothrombin time or INR in patients taking coumarin-derived anticoagulants. Dose modifications of erlotinib tablets are not recommended [see Warnings and Precautions (5.9) and Adverse Reactions (6.1) ] . CYP3A4 inhibitors or a combined CYP3A4 and CYP1A2 inhibitor increase erlotinib plasma concentrations. Avoid concomitant use. If not possible, reduce erlotinib dose. ( 2.4 , 7 ) CYP3A4 inducers decrease erlotinib plasma concentrations. Avoid concomitant use. If not possible, increase erlotinib dose. ( 2.4 , 7 ) Cigarette smoking and CYP1A2 inducers decrease erlotinib plasma concentrations. Avoid concomitant use. If not possible, increase erlotinib dose. ( 2.4, 7 ) Drugs that increase gastric pH decrease erlotinib plasma concentrations. For proton pump inhibitors avoid concomitant use if possible. For H-2 receptor antagonists, take erlotinib 10 hours after H-2 receptor antagonist dosing. For use with antacids, separate dosing by several hours. ( 2.4 , 7 )
AND PRECAUTIONS Interstitial lung disease (ILD) : Occurs in 1.1% of patients. Withhold erlotinib tablets for acute onset of new or progressive unexplained pulmonary symptoms, such as dyspnea, cough and fever. Discontinue erlotinib if ILD is diagnosed. ( 5.1 ) Renal failure : Monitor renal function and electrolytes, particularly in patients at risk of dehydration. Withhold erlotinib tablets for severe renal toxicity. ( 5.2 ) Hepatotoxicity : Occurs with or without hepatic impairment, including hepatic failure and hepatorenal syndrome: Monitor periodic liver testing. Withhold or discontinue erlotinib tablets for severe or worsening liver tests. ( 5.3 ) Gastrointestinal perforations : Discontinue erlotinib tablets. ( 5.4 ) Bullous and exfoliative skin disorders : Discontinue erlotinib tablets. ( 5.5 ) Cerebrovascular accident (CVA) : The risk of CVA is increased in patients with pancreatic cancer. ( 5.6 ) Microangiopathic hemolytic anemia (MAHA) : The risk of MAHA is increased in patients with pancreatic cancer. ( 5.7 ) Ocular disorders : Discontinue erlotinib tablets for corneal perforation, ulceration or persistent severe keratitis. ( 5.8 ) Hemorrhage in patients taking warfarin : Regularly monitor INR in patients taking warfarin or other coumarin-derivative anticoagulants. ( 5.9 ) Embryo-fetal toxicity : Can cause fetal harm. Advise females of reproductive potential of the potential risk to the fetus and to use effective contraception.( 5.10 , 8.1 , 8.3 )
5.1 Interstitial Lung Disease (ILD) Cases of serious ILD, including fatal cases, can occur with erlotinib tablets treatment. The overall incidence of ILD in approximately 32,000 erlotinib tablets-treated patients in uncontrolled studies and studies with concurrent chemotherapy was approximately 1.1%. In patients with ILD, the onset of symptoms was between 5 days to more than 9 months (median 39 days) after initiating erlotinib tablets therapy. Withhold erlotinib tablets for acute onset of new or progressive unexplained pulmonary symptoms such as dyspnea, cough, and fever pending diagnostic evaluation. If ILD is confirmed, permanently discontinue erlotinib tablets <span class="opacity-50 text-xs">[see Dosage and Administration (2.4) ]</span> .
5.2 Renal failure Hepatorenal syndrome, severe acute renal failure including fatal cases, and renal insufficiency can occur with erlotinib tablet treatment. Renal failure may arise from exacerbation of underlying baseline hepatic impairment or severe dehydration. The pooled incidence of severe renal impairment in the 3 monotherapy lung cancer studies was 0.5% in the erlotinib tablets arms and 0.8% in the control arms. The incidence of renal impairment in the pancreatic cancer study was 1.4% in the erlotinib tablet plus gemcitabine arm and 0.4% in the control arm. Withhold erlotinib tablet in patients developing severe renal impairment until renal toxicity is resolved. Perform periodic monitoring of renal function and serum electrolytes during erlotinib tablet treatment <span class="opacity-50 text-xs">[see Adverse Reactions (6.1) and Dosage and Administration (2.4) ]</span> .
5.3 Hepatotoxicity with or without Hepatic Impairment Hepatic failure and hepatorenal syndrome, including fatal cases, can occur with erlotinib tablet treatment in patients with normal hepatic function; the risk of hepatic toxicity is increased in patients with baseline hepatic impairment. In clinical studies where patients with moderate to severe hepatic impairment were excluded, the pooled incidence of hepatic failure in the 3 monotherapy lung cancer studies was 0.4% in the erlotinib tablet arms and 0% in the control arms. The incidence of hepatic failure in the pancreatic cancer study was 0.4% in the erlotinib tablet plus gemcitabine arm and 0.4% in the control arm. In a pharmacokinetic study in 15 patients with moderate hepatic impairment (Child-Pugh B) associated with significant liver tumor burden, 10 of these 15 patients died within 30 days of the last erlotinib tablet dose. One patient died from hepatorenal syndrome, 1 patient died from rapidly progressing liver failure and the remaining 8 patients died from progressive disease. Six out of the 10 patients who died had baseline total bilirubin > 3 x ULN. Perform periodic liver testing (transaminases, bilirubin, and alkaline phosphatase) during treatment with erlotinib tablets. Increased frequency of monitoring of liver function is required for patients with pre-existing hepatic impairment or biliary obstruction. Withhold erlotinib tablets in patients without pre-existing hepatic impairment for total bilirubin levels greater than 3 times the upper limit of normal or transaminases greater than 5 times the upper limit of normal. Withhold erlotinib tablets in patients with pre-existing hepatic impairment or biliary obstruction for doubling of bilirubin or tripling of transaminases values over baseline. Discontinue erlotinib tablets in patients whose abnormal liver tests meeting the above criteria do not improve significantly or resolve within three weeks <span class="opacity-50 text-xs">[see Dosage and Administration (2.4) and Clinical Pharmacology (12.3) ]</span>
5.4 Gastrointestinal Perforation Gastrointestinal perforation, including fatal cases, can occur with erlotinib tablets treatment. Patients receiving concomitant anti-angiogenic agents, corticosteroids, NSAIDs, or taxane-based chemotherapy, or who have prior history of peptic ulceration or diverticular disease may be at increased risk of perforation <span class="opacity-50 text-xs">[see Adverse Reactions (6.1 , 6.2) ]</span> . The pooled incidence of gastrointestinal perforation in the 3 monotherapy lung cancer studies was 0.2% in the erlotinib tablets arms and 0.1% in the control arms. The incidence of gastrointestinal perforation in the pancreatic cancer study was 0.4% in the erlotinib tablets plus gemcitabine arm and 0% in the control arm. Permanently discontinue erlotinib tablets in patients who develop gastrointestinal perforation <span class="opacity-50 text-xs">[see Dosage and Administration (2.4) ]</span> .
5.5 Bullous and Exfoliative Skin Disorders Bullous, blistering and exfoliative skin conditions, including cases suggestive of Stevens-Johnson syndrome/toxic epidermal necrolysis, which in some cases were fatal, can, occur with erlotinib tablets treatment <span class="opacity-50 text-xs">[see Adverse Reactions (6.1 , 6.2) ]</span> . The pooled incidence of bullous and exfoliative skin disorders in the 3 monotherapy lung cancer studies was 1.2% in the erlotinib tablets arms and 0% in the control arms. The incidence of bullous and exfoliative skin disorders in the pancreatic cancer study was 0.4% in the erlotinib tablets plus gemcitabine arm and 0% in the control arm. Discontinue erlotinib tablets treatment if the patient develops severe bullous, blistering or exfoliating conditions <span class="opacity-50 text-xs">[see Dosage and Administration (2.4) ]</span> .
5.6 Cerebrovascular Accident In the pancreatic carcinoma trial, seven patients in the erlotinib tablets/gemcitabine group developed cerebrovascular accidents (incidence: 2.5%). One of these was hemorrhagic and was the only fatal event. In comparison, in the placebo/gemcitabine group there were no cerebrovascular accidents. The pooled incidence of cerebrovascular accident in the 3 monotherapy lung cancer studies was 0.6% in the erlotinib tablets arms and not higher than that observed in the control arms.
5.7 Microangiopathic Hemolytic Anemia with Thrombocytopenia The pooled incidence of microangiopathic hemolytic anemia with thrombocytopenia in the 3 monotherapy lung cancer studies was 0% in the erlotinib tablets arms and 0.1% in the control arms. The incidence of microangiopathic hemolytic anemia with thrombocytopenia in the pancreatic cancer study was 1.4% in the erlotinib tablets plus gemcitabine arm and 0% in the control arm.
5.8 Ocular Disorders Decreased tear production, abnormal eyelash growth, keratoconjunctivitis sicca or keratitis can occur with erlotinib tablets treatment and can lead to corneal perforation or ulceration <span class="opacity-50 text-xs">[see Adverse Reactions (6.1) and (6.2) ]</span> . The pooled incidence of ocular disorders in the 3 monotherapy lung cancer studies was 17.8% in the erlotinib tablets arms and 4% in the control arms. The incidence of ocular disorders in the pancreatic cancer study was 12.8% in the erlotinib tablets plus gemcitabine arm and 11.4% in the control arm. Interrupt or discontinue erlotinib tablets therapy if patients present with acute or worsening ocular disorders such as eye pain <span class="opacity-50 text-xs">[see Dosage and Administration (2.4) ]</span> .
5.9 Hemorrhage in Patients Taking Warfarin Severe and fatal hemorrhage associated with International Normalized Ratio (INR) elevations can occur when erlotinib tablets and warfarin are administered concurrently. Regularly monitor prothrombin time and INR during erlotinib tablets treatment in patients taking warfarin or other coumarin-derivative anticoagulants <span class="opacity-50 text-xs">[see Adverse Reactions (6.1) and Drug Interactions (7) ]</span> .
5.10 Embryo-fetal Toxicity Based on animal data and its mechanism of action, erlotinib tablets can cause fetal harm when administered to a pregnant woman. When given during organogenesis, erlotinib administration resulted in embryo-fetal lethality and abortion in rabbits at exposures approximately 3 times the exposure at the recommended human daily dose of 150 mg. Advise pregnant women of the potential risk to a fetus. Advise females of reproductive potential to use effective contraception during therapy and for one month after the last dose of erlotinib tablets <span class="opacity-50 text-xs">[see Use in Specific Populations (8.1) and (8.3) , Clinical Pharmacology (12.1) ]</span> .