Combinib 250mg Tablet (Lapatinib Ditosylate) is a dual EGFR and HER2 tyrosine kinase inhibitor approved for HER2-positive breast cancer treatment. Composition: Each tablet contains 250mg Lapatinib ditosylate with pharmaceutical excipients optimized for oral bioavailability. Indications: Lapatinib treats advanced HER2-positive metastatic breast cancer (MBC) in combination with capecitabine; trastuzumab-resistant HER2+ disease; potential use in HER2+ gastric cancers and other HER2-expressing malignancies. Clinical efficacy demonstrates improved time-to-progression and overall survival versus capecitabine monotherapy in HER2+ MBC. Contraindications: Absolute contraindications include hypersensitivity to lapatinib, uncorrected hypokalemia, uncontrolled cardiac arrhythmias, and baseline QTc >500ms. Relative caution in hepatic impairment, cardiac disease, or interstitial lung disease history. Drug Interactions: Significant interactions with CYP3A4 inhibitors (ketoconazole, ritonavir increase levels), CYP3A4 inducers (carbamazepine, phenytoin reduce levels), P-gp substrates (digoxin), and drugs affecting QTc interval. Dosage & Administration: Standard dosing is 1250mg (five 250mg tablets) once daily in combination with capecitabine 2000mg/m2 daily on days 1-14 of 21-day cycles. Take on empty stomach 1 hour before/after meals. Storage: 15-30°C in original protective packaging away from light. Side Effects: Common: diarrhea (65%), hand-foot syndrome (when combined with capecitabine), nausea, fatigue, rash. Serious: hepatotoxicity, QTc prolongation, ventricular dysfunction (ejection fraction reduction), interstitial pneumonitis. Precautions & Warnings: Baseline and quarterly ECG monitoring; baseline and monthly LFTs; ejection fraction assessment before therapy and every 3 months; aggressive diarrhea management; electrolyte monitoring for hypokalemia. Pregnancy & Lactation: Lapatinib is teratogenic (Category D); absolutely contraindicated in pregnancy and lactation. Males require barrier contraception during therapy and 5 days post-treatment. Females require hormonal contraception plus barrier methods with pregnancy testing baseline and monthly. Substitutes & Alternatives: Trastuzumab for HER2+ breast cancer; pertuzumab combined with trastuzumab and chemotherapy; newer agents (T-DM1, tucatinib) for trastuzumab-resistant disease. FAQs: Expected response time 8-12 weeks; diarrhea management with dietary modifications and antidiarrheals; cost significantly higher; long-term toxicity monitoring essential; treatment duration until progression or intolerance. Expected Timeline: Baseline cardiac assessment; Week 2 tolerability check; Week 8 clinical response assessment; Month 3 imaging evaluation (RECIST); ongoing monthly surveillance. Book Breast Oncology Consultation: Essential for HER2 status confirmation, combination therapy optimization, cardiac monitoring coordination, and toxicity management. Schedule Tests: Baseline CBC, LFTs, electrolytes, troponin, MUGA/echocardiogram; monthly LFTs x 3 months then quarterly; monthly electrolyte assessment; baseline and monthly ECG; baseline and monthly ejection fraction measurement; monthly CT chest/abdomen.