Tykerb (lapatinib) Tablets
Detailed View: Safety Labeling Changes Approved By FDA Center for Drug Evaluation and Research (CDER) -- July 2008, August 2011, and February 2012
Acid Reducing Agents
- The aqueous solubility of lapatinib is pH dependent, with higher pH resulting in lower solubility. However, esomeprazole, a proton pump inhibitor, administered at a dose of 40 mg once daily for 7 days, did not result in a clinically meaningful reduction in lapatinib steady-state exposure.
Effects of Lapatinib on Drug Metabolizing Enzymes and Drug Transport Systems
- Midazolam: Following coadministration of Tykerb and midazolam (CYP3A4 substrate), 24-hour systemic exposure (AUC) of orally administered midazolam increased 45%,while 24-hour AUC of intravenously administered midazolam increased 22%.
- Digoxin: Following coadministration of Tykerb and digoxin (P-gp substrate), systemic AUC of an oral digoxin dose increased approximately 2.8-fold. Serum digoxin concentrations should be monitored prior to initiation of Tykerb and throughout coadministration. If digoxin serum concentration is >1.2 ng/mL, the digoxin dose should be reduced by half
|The detailed view includes drug products with safety labeling changes to the BOXED WARNING, CONTRAINDICATIONS, WARNINGS, PRECAUTIONS, ADVERSE REACTIONS, or PATIENT PACKAGE INSERT/MEDICATION GUIDE sections. Deletions or editorial revisions made to these sections are not included in this summary.|
|Sections Modified||Summary of Changes to Contraindications and Warnings|
WARNINGS AND PRECAUTIONS
USE IN SPECIFIC POPULATIONS
PATIENT PACKAGE INSERT
Hepatotoxicity has been observed in clinical trials and postmarketing experience. The hepatotoxicity may be severe and deaths have been reported. Causality of the deaths is uncertain. [See Warnings and Precautions (5.2).]
WARNINGS AND PRECAUTIONS
Hepatotoxicity (ALT or AST >3 times the upper limit of normal and total bilirubin >1.5 times the upper limit of normal) has been observed in clinical trials (<1% of patients) and postmarketing experience. The hepatotoxicity may be severe and deaths have been reported. Causality of the deaths is uncertain. The hepatotoxicity may occur days to several months after initiation of treatment. Liver function tests (transaminases, bilirubin, and alkaline phosphatase) should be monitored before initiation of treatment, every 4 to 6 weeks during treatment, and as clinically indicated. If changes in liver function are severe, therapy with Tykerb should be discontinued and patients should not be retreated with Tykerb [see Adverse Reactions (6.1)].
Patients with Severe Hepatic Impairment
...In patients who develop severe hepatotoxicity while on therapy, Tykerb should be discontinued and patients should not be retreated with Tykerb [see Warnings and Precautions (5.2)]