The anti-tumour drug Pazopanib: Uses, Mechanism of action and Side effects

Uses of Pazopanib

Pazopanib is a targeted anticancer drug for the treatment of advanced kidney cancer and advanced soft tissue sarcoma previously treated with chemotherapy. It was developed by GlaxoSmithKline and approved by the FDA on 19 October 2009 as a small molecule inhibitor of several protein tyrosine kinases with potential anti-tumour activity.

Pazopanib is taken by mouth using tablets; do not split, chew or crush them. It is usually taken once a day on an empty stomach, at least 1 hour before or 2 hours after a meal. Take pazopanib at about the same time each day.

Mechanism of action

Pazopanib is a second-generation multitargeted tyrosine kinase inhibitor against vascular endothelial growth factor receptor-1, -2, and -3, platelet-derived growth factor receptor-alpha, platelet-derived growth factor receptor-beta, and c-kit. These receptor targets are part of the angiogenesis pathway that facilitates the formation of tumour blood vessel for tumour survival and growth.

Side effects of Pazopanib

Pazopanib common side effects (> 10%) include:

• Diarrhoea

• Skin problems

• Tiredness and weakness (fatigue)
  

• Change in hair colour

• Hair Loss
  

• Feeling or being sick

• High blood pressure (hypertension)

• Loss of appetite
  

• Headaches

• Liver changes
  

• Soreness, redness and peeling on palms and soles of the feet
  

Occasional side effects (1~10%) include:

• indigestion, symptoms include heartburn, bloating and burping
  

• low levels of thyroid hormones, symptoms might include feeling quite tired, being more sensitive to the cold, gaining weight, and being constipated
  

• low levels of a mineral in the blood called phosphate and rarely magnesium – you have regular blood tests to check for this
  

• breathlessness and looking pale
  

• difficulty sleeping (insomnia)
  

• blood clots that can be life threatening; signs are pain, redness and swelling where the clot is. Feeling breathless can be a sign of a blood clot in the lung. Contact your advice line or doctor straight away if you have any of these symptoms
  

• dizziness
  

• blurred vision, rarely you might have eyesight changes and your eyelashes may change colour
  

• swelling to different parts of the body such as your hands, feet, eyes and face
  

• numbness or tingling in the hands and feet
  

• muscle pain and muscle cramps
  

• increased risk of getting an infection
  

• sore mouth or ulcers, your mouth might also get dry
  

• bleeding from different parts of the body such as coughing up blood. Rarely you might bleed from other areas such as mouth, vagina or bottom, let your doctor or nurse know if you notice any bleeding
  

• difficulty breathing – let your team straight away if you are finding it difficult to breathe

Rare side effects (< 1%) include:

• a hole in the bowel wall (bowel perforation)
  

• heart problems – such as problems your heart muscle not being able to pump blood around the body properly, blood supply problems to part of the heart or changes to the heart rhythm
  

• a stroke, symptoms include numbness or weakness on one side of your body, difficulty talking, headache or dizziness
  

• nail changes such as a change in colour, texture or breaking easily
  

• feeling extremely tired or drowsy (somnolence)
  

• a high number of red blood cells in your blood making it thicker and less able to run through your blood vessels easily causing blockages
  

• temporary lack of blood supply to the brain (transient ischaemic attack)
  

• collapsed lung with air trapped in the space between the lung and chest, often causing shortness of breath (pneumothorax)
  

• inflammation of the pancreas, symptoms might include feeling or being sick, diarrhoea, indigestion, high temperature and yellowing of the skin or whites of the eyes
  

• runny nose
  

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