Tyrodin

Indications

Cinacalcet is used to treat secondary hyperparathyroidism in adults with long-term kidney disease who are on dialysis. In this condition the parathyroid glands make too much parathyroid hormone (PTH), which can weaken bones and upset calcium and phosphate balance. It is also used to lower high blood calcium in parathyroid cancer and in some people with primary hyperparathyroidism who cannot have surgery.

How It Works

Cinacalcet is a calcimimetic: it makes the calcium-sensing receptors on the parathyroid glands more sensitive to calcium in the blood. The glands then release less PTH, which lowers blood calcium and phosphate levels and protects the bones.

Dosage and Administration

Take exactly as prescribed. The doctor usually starts with a low dose once a day and increases it gradually every few weeks, based on blood tests of PTH and calcium. Swallow the tablet whole with food or shortly after a meal; do not split or crush it. Do not change the dose yourself.

Interactions

Strong enzyme inhibitors such as Ketoconazole, Itraconazole and Clarithromycin can raise Cinacalcet levels. Cinacalcet can raise levels of some medicines broken down by the liver enzyme CYP2D6, such as Metoprolol, Flecainide, Tricyclic antidepressants and Desipramine. Smoking can lower its levels. Other medicines that lower calcium, such as Etelcalcetide, should not be combined with it.

Contraindications

• Allergy to Cinacalcet or any ingredient of the tablet.
• Blood calcium already below the normal range.

Side Effects

Common side effects include nausea, vomiting, diarrhoea, loss of appetite, dizziness, muscle aches, tiredness and rash. Low blood calcium can cause tingling around the mouth or in the fingers, muscle cramps or twitching.

Get urgent medical help for fits (seizures), severe muscle spasms, a fast or irregular heartbeat, fainting, vomiting blood or black stools, or signs of allergy such as swelling of the face or throat.

Pregnancy and Lactation

There is little information on use in pregnancy; use only if a doctor decides the benefit outweighs the risk. It is not known whether it passes into breast milk; your doctor will decide whether to stop breastfeeding or the medicine.

Precautions and Warnings

Regular blood tests for calcium and PTH are needed, especially when starting or changing the dose. Tell your doctor if you have a history of fits, heart failure, heart rhythm problems, liver disease, or stomach bleeding. Low calcium can trigger fits and heart rhythm changes.

Overdose

Overdose may cause low blood calcium with tingling, muscle cramps, spasms or fits. Seek medical help immediately; blood calcium will need to be checked.

Therapeutic Class

Calcimimetic agent; parathyroid hormone-lowering drug.

Storage

Store below 30°C in a dry place, away from light and out of the reach of children.