Paloset

Indications

Palonosetron is used to prevent nausea and vomiting caused by cancer chemotherapy, both the early sickness in the first day and the delayed sickness in the days after treatment. The injection is also used to prevent nausea and vomiting after surgery and anaesthesia.

How It Works

Chemotherapy and surgery can release serotonin in the gut, which sends signals to the brain that trigger nausea and vomiting. Palonosetron blocks the serotonin (5-HT3) receptors that receive these signals. It lasts a long time in the body, so one dose covers several days.

Dosage and Administration

• Injection: given into a vein by a doctor or nurse, usually as a single dose about 30 minutes before chemotherapy, or just before surgery, as prescribed.
• Capsules (where available): usually one capsule about 1 hour before chemotherapy, as prescribed.

It is not usually repeated within 7 days unless the doctor decides. It is often given together with a steroid such as Dexamethasone and other anti-sickness medicines.

Interactions

Using it with other medicines that raise serotonin, such as antidepressants (for example Sertraline, Fluoxetine and Venlafaxine), Tramadol, Fentanyl, Methylene Blue or triptans for migraine, can rarely cause serotonin syndrome. Tell the doctor about all medicines, including herbal products.

Contraindications

• Allergy to palonosetron or to similar anti-sickness medicines such as Ondansetron or Granisetron.

Side Effects

Common: headache, constipation, dizziness, tiredness and, less often, diarrhoea or mild pain at the injection site.

Get urgent medical help for: signs of a severe allergic reaction (swelling of the face, lips or throat, difficulty breathing, widespread rash), a fast, slow or irregular heartbeat or fainting, or signs of serotonin syndrome such as agitation, confusion, fever, sweating, shaking, stiff muscles or fast heartbeat.

Pregnancy and Lactation

There is limited information on use in pregnancy; it should be used only if the doctor judges it necessary. It is not known whether it passes into breast milk; the doctor will advise whether to pause breastfeeding.

Precautions and Warnings

Tell the doctor about any heart rhythm problem, a family history of heart rhythm problems, or low potassium or magnesium in the blood. It can make constipation worse; tell the doctor if you have had a bowel blockage. It prevents sickness but may not stop it completely; let the care team know if vomiting continues.

Overdose

Because it is given by healthcare staff, overdose is unlikely. There is no specific antidote; any effects are treated with supportive care in hospital.

Therapeutic Class

Antiemetic; serotonin (5-HT3) receptor antagonist.

Storage

Store below 30°C, protected from light and out of the reach of children. Do not freeze. Injections are stored and handled by hospital or clinic staff.