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Mechanism of Action of Lapatinib
Lapatinib is a 4-anilino quinazoline kinase inhibitor of the intracellular tyrosine kinase domains of both epidermal growth factor receptor (HER1/EGFR/ERBB1) and human epidermal growth factor receptor type 2 (HER2/ERBB2)with a dissociation half-life of ≥300 minutes. Lapatinib inhibits ERBB-driven tumor cell growth in vitro and in various animal models. An additive effect was demonstrated in an in vitro study when lapatinib and 5-fluorouracil (the active metabolite of capecitabine) were used in combination in the 4 tumor cell lines tested. The growth inhibitory effects of lapatinib were evaluated in trastuzumab-conditioned cell lines. Lapatinib retained significant activity against breast cancer cell lines selected for long-term growth in the trastuzumab-containing medium in vitro. These in vitro findings suggest non-cross-resistance between these two agents.
Lapatinib Ditosylate is the ditosylate salt of lapatinib, a synthetic, orally-active quinazoline with potential antineoplastic activity. Lapatinib reversibly blocks phosphorylation of the epidermal growth factor receptor (EGFR), ErbB2, and the Erk-1 and-2 and AKT kinases; it also inhibits cyclin D protein levels in human tumor cell lines and xenografts. EGFR and ErbB2 have been implicated in the growth of various tumor types.
Lapatinib Indications
- Indicated in combination with capecitabine for the treatment of patients with advanced or metastatic breast cancer whose tumors overexpress the human epidermal receptor type 2 (HER2) protein and who have received prior therapy including an anthracycline, a taxane, and trastuzumab.
- Treatment of adult patients with breast cancer, whose tumors overexpress HER2 (ErbB2);
in combination with capecitabine for patients with advanced or metastatic disease with progression following prior therapy, which must have included anthracyclines and taxanes and therapy with trastuzumab in the metastatic setting in combination with trastuzumab for patients with hormone receptor-negative metastatic disease that has progressed on prior trastuzumab therapy is in combination with chemotherapy in combination with an aromatase inhibitor for postmenopausal women with hormone receptor-positive metastatic disease, not currently intended for chemotherapy. - The patients in the registration study were not previously treated with trastuzumab or an aromatase inhibitor. No data are available on the efficacy of this combination relative to trastuzumab in combination with an aromatase inhibitor in this patient population.
- Lapatinib is a tyrosine kinase receptor inhibitor used in the therapy of advanced breast cancer and other solid tumors. Lapatinib therapy is associated with transient elevations in serum aminotransferase levels and rare instances of clinically apparent acute liver injury.
- Breast Cancer
- Breast Cancer, Metastatic
- Refractory, advanced Breast cancer
- Refractory, metastatic Breast cancer
Lapatinib Contraindications
- Severe infection
- insulin is low or not working well. সহজ বাংলা: রক্তে চিনি বেশি থাকার রোগ।" data-rx-term="diabetes" data-rx-definition="Diabetes is a condition where blood sugar stays too high because insulin is low or not working well. সহজ বাংলা: রক্তে চিনি বেশি থাকার রোগ।">Diabetes
- Anemia
- Decreased Blood Platelets
- Severely Decreased Platelets
- Decreased Neutrophils a Type of White Blood Cell
- Peripheral pain, numbness, tingling, or weakness. সহজ বাংলা: স্নায়ুর ক্ষতি/সমস্যা।" data-rx-term="neuropathy" data-rx-definition="Neuropathy means nerve damage or irritation causing pain, numbness, tingling, or weakness. সহজ বাংলা: স্নায়ুর ক্ষতি/সমস্যা।">neuropathy
- Disease of Inadequate Blood Flow to the Heart Muscle
- Abnormal heart rhythm
- Heart Disease
- Liver problems
- Severe liver disease
- High Amount of jaundice. সহজ বাংলা: জন্ডিসে বাড়তে পারে এমন হলুদ রঞ্জক।" data-rx-term="bilirubin" data-rx-definition="Bilirubin is a yellow pigment that can build up in jaundice. সহজ বাংলা: জন্ডিসে বাড়তে পারে এমন হলুদ রঞ্জক।">Bilirubin in the Blood
- Abnormal liver function tests
- Pregnancy
- A mother who is producing milk and breastfeeding
- Severely Decreased Levels of Neutrophils in the Blood
Dosage of Lapatinib
Strengths: 250 mg
Breast Cancer
- HER2-POSITIVE METASTATIC BREAST CANCER (in combination with capecitabine): 1250 mg orally once a day on Days 1 to 21 continuously in repeating 21-day cycles until disease progression or unacceptable toxicity.
- HORMONE RECEPTOR-POSITIVE, HER2-POSITIVE METASTATIC BREAST CANCER (in combination with letrozole): 1500 mg orally once a day continuously.
Side Effects of Lapatinib
The Most Common
- Abdominal or stomach pain or tenderness
- diarrhea
- symptoms of heart problems (e.g., shortness of breath, swelling of the ankles or feet, chest pain, irregular heartbeat)
- symptoms of liver problems (e.g., nausea, vomiting, abdominal pain, yellowing of the skin and eyes, itchy skin, dark urine)
- symptoms of lung problems (e.g., shortness of breath or difficulty breathing, chest pain, cough)
- symptoms of a severe allergic reaction (e.g., hives; difficulty breathing; swelling of the face, mouth, tongue, or throat)
- signs of a severe skin reaction such as blistering, peeling, a rash covering a large area of the body, a rash that spreads quickly, or a rash combined with fever or discomfort
More Common
- Acid or sour stomach
- back pain
- belching
- cracked lips
- diarrhea (mild)
- dry skin
- heartburn
- indigestion
- pain in the arms or legs
- redness, swelling, or painful skin
- scaling of the skin on the hands and feet
- sores, ulcers, or white spots on the lips, tongue, or the inside of the mouth
Rare
- Black, tarry stools
- body aches or pain
- burning, numbness, tingling, or painful sensations
- burning pain on urination
- chest pain
- chills
- cough
- difficult or labored breathing
- ear congestion
- fever
- pain in the head or upper neck. সহজ বাংলা: মাথাব্যথা।" data-rx-term="headache" data-rx-definition="Headache means pain in the head or upper neck. সহজ বাংলা: মাথাব্যথা।">headache
- loss of voice
- lower back or side pain
- nasal congestion
- painful or difficult urination
- pale skin
- red, swelling, or painful skin
Drug Indications of Lapatinib
Lapatinib Ditosylate may interact with following drugs, supplements & may change the efficacy of drugs
- calcium channel blockers (e.g., amlodipine, diltiazem, nifedipine, verapamil)
- carbamazepine
- carvedilol
- cetirizine
- corticosteroids (e.g., prednisone, dexamethasone)
- cyclosporine
- desipramine
- dexamethasone
- domperidone
- doxorubicin
- dronedarone
- estrogens
- everolimus
- “gliptin” diabetes medications (e.g., linagliptin, saxagliptin, sitagliptin)
- “glitazone” diabetes medications
- hydrocortisone
- loperamide
- macrolide antibiotics (e.g., clarithromycin, erythromycin)
- methadone
- methotrexate
- metronidazole
- mirabegron
- modafinil
- nadolol
- phenobarbital
- phenytoin
- prazosin
- progesterone
- propranolol
- protein kinase inhibitors (e.g., pazopanib, sunitinib)
- quinolone antibiotics (e.g., ciprofloxacin, norfloxacin, ofloxacin)
- ranitidine
- repaglinide
- St. John’s Wort
- serotonin antagonists (anti-emetics; e.g., granisetron, ondansetron)
- sertraline
- sotalol
- “statin” anti-cholesterol medications (e.g., atorvastatin, lovastatin, simvastatin)
- tacrolimus
Pregnancy Category
AU TGA Pregnancy Category: C
US FDA Pregnancy Category: D
Pregnancy
This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately. Women who may become pregnant should use contraception and avoid becoming pregnant while they are taking this medication.
Lactation
It is not known if lapatinib passes into breast milk. If you are a breastfeeding mother and are taking this medication, it may affect your baby. Talk to your doctor about whether you should breastfeeding. Breastfeeding while taking this medication is not recommended. The safety and effectiveness of using this medication have not been established for children.
References
