Lapatinib

Cytostatic · Protein kinase inhibitor

Indications

Advanced or metastatic breast-cancer in patients with tumours that over express human epidermal growth factor receptor-2 (HER2). In combination with capecitabine, for patients who have had previous treatment with an anthracycline, a taxane and trastuzumab, or for post-menopausal women in combination with an aromatase inhibitor.

Dosage

Adults: In combination with capecitabine, 1.25 gm once daily as a single dose. In combination with aromatase inhibitor, 1.5 gm once daily. In combination with trastuzumab, 1 gm once daily. Counselling: Always take at the same time in relation to food, either 1 hr before or 1 hr after food.

Adverse Effects

Diarrhoea, decrease LVEF, rash, GI upsets, stomatitis, anorexia, fatigue, headache, dry skin, hyperbilirubinaemia, hepatotoxicity, back pain, insomnia, mucosal inflammation, cough, dyspnoea, alopecia, pruritus, arrhythmia, back pain, epistaxis, pain in extremities, arthralgia, asthenia, hand-foot syndrome, alopecia, pruritus, nail disorders. Reports of Stevens-Johnson syndrome, toxic epidermal necrolysis (discontinue).

Risk Factor (Pregnancy/Lactation)

Pregnancy: Contraindicated in pregnancy. Lactation: Contraindicated or not recommended. Contraindications: Hypersensitivity. Precautions: Severe renal or hepatic impairment, monitor LFTs, caution in patients in conditions that impair left ventricular function; monitor for pulmonary toxicity. Risk factor for QT prolongation, monitor left ventricular ejection fraction (LVEF). Ensure adequate contraception. Risk of diarrhoea.

Interactions

CYP3A4 inhibitors (incl ritonavir, saquinavir, telithromycin, azole antifungals, nefazodone, grapefruit juice) or inducers (incl carbamazepine, rifampicin, rifabutin, phenytoin, St John's wort). Substrates of CYP3A4 or CYP2C8 with a narrow therapeutic index (e.g., pimozide, repaglinide), drugs that increase gastric pH or prolong QT interval, cardiotoxic agents, verapamil, ciclosporin, erythromycin, digoxin, topotecan, irinotecan, rosuvastatin, paclitaxel.

Advice to Patient

Take atleast 1 hour before or 1 hour after meals. Contact prescriber if there is dizziness, tiredness, light headedness, shortness of breath, severe cough, fast heartbeat, chest pain, palpitations, itching, dark coloured urine, diarrhoea, change in bowel pattern, yellowing of eyes or skin, abdominal pain. Avoid grapefruit juice and products containing grapefruit during therapy.

Pharmacokinetics

Absorption: Incomplete and variable. Metabolism: Hepatic. Half-life elimination: Approx. 24 hours. Time to peak. Plasma: Approx. 4 hours. Excretion: Feces (27% as unchanged drug; range 3% to 67%); urine (<2%).

Brands with this active ingredient

• Lepta
• Tykerb
• Tykerb

Compiled by Healify Pharmacy from published drug references. How we compile it →

Always consult a pharmacist or doctor.