Indications
Vandetanib is an anticancer medicine used to treat medullary thyroid cancer (a cancer arising from the C cells of the thyroid gland) that cannot be removed by surgery or has spread to other parts of the body and is causing symptoms or growing.
How It Works
Vandetanib is a kinase inhibitor. It blocks several signalling proteins on cells, including the RET protein (often faulty in medullary thyroid cancer), the vascular endothelial growth factor receptor (VEGFR), which tumours use to grow new blood vessels, and the epidermal growth factor receptor (EGFR). Blocking these signals slows the growth and spread of the cancer.
Dosage and Administration
Vandetanib is prescribed and supervised by a cancer specialist. Take it once a day, at about the same time each day, with or without food, exactly as prescribed. The dose may be lowered if side effects occur or if you have kidney problems. If you have trouble swallowing, ask your doctor or pharmacist how the tablet can be dispersed in water. An ECG (heart tracing) and blood tests for potassium, calcium, magnesium and thyroid hormone are done before starting and regularly during treatment.
Interactions
- Other medicines that prolong the QT interval, such as Amiodarone, Sotalol, Clarithromycin, Moxifloxacin, Ondansetron, Haloperidol and Methadone: risk of dangerous heart rhythms; usually avoided.
- Strong enzyme inducers such as Rifampicin, Carbamazepine, Phenytoin and St John’s Wort: lower Vandetanib levels.
- Metformin and Digoxin: levels may rise.
- Diuretics that lower potassium or magnesium: increase rhythm risk.
Contraindications
Do not take Vandetanib if you are allergic to it, were born with long QT syndrome or have a QT interval that is already prolonged, or are breastfeeding.
Side Effects
Very common side effects include diarrhoea, rash, acne-like spots, dry skin, sensitivity to sunlight, nausea, high blood pressure, headache, tiredness, loss of appetite and stomach pain. Vandetanib can prolong the QT interval and cause serious heart rhythm problems.
Get urgent medical help if you faint, feel your heart beating very fast or irregularly, have severe dizziness, chest pain, severe or ongoing diarrhoea, a severe skin reaction with blisters or peeling, sudden breathlessness or cough, severe headache with confusion or vision changes, or bleeding that does not stop.
Pregnancy and Lactation
Vandetanib can harm an unborn baby. Women who can become pregnant must use effective contraception during treatment and for at least 4 months after the last dose. Do not breastfeed during treatment and for 4 months after the last dose.
Precautions and Warnings
Keep all ECG and blood test appointments. Treat diarrhoea promptly and drink plenty of fluids, since losing fluids and salts increases the risk of rhythm problems. Protect your skin from the sun with clothing and sunscreen during treatment and for 4 months after. Your doctor may adjust thyroid hormone tablets. Use with care in kidney disease and high blood pressure.
Overdose
An overdose may cause dangerous heart rhythms, severe diarrhoea and rash. Get emergency medical help straight away.
Therapeutic Class
Anticancer agent, tyrosine kinase inhibitor.
Storage
Store below 30°C in a dry place, away from light and out of the reach of children.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.