Before you begin using a medication, be sure to inform your doctor of any medical conditions or Allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use Sensipar (Cinacalcet).

Abnormal heart rhythms: Sensipar (Cinacalcet) can cause abnormal heart rhythms when there are low blood calcium levels. Contact your doctor immediately if you develop an unusually fast or pounding heartbeat. If you have heart disease and abnormal heart rhythms, or are taking certain medications (e.g., Verapamil, atazanavir), discuss with your doctor how Sensipar (Cinacalcet) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Sensipar (Cinacalcet), and whether any special monitoring is needed.

Heart failure: Sensipar (Cinacalcet) has been reported to cause worsening heart failure for people who have poor heart function or heart disease. If you have heart disease, discuss with your doctor how Sensipar (Cinacalcet) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Sensipar (Cinacalcet), and whether any special monitoring is needed.

Report any signs of worsening heart failure such as difficulty breathing, swelling in the ankles or hands, cough, or chest pain to your doctor as soon as possible.

Low blood calcium levels: Sensipar (Cinacalcet) helps to reduce the level of calcium in the blood. Occasionally, it may cause the level to become too low. Your doctor will monitor the amount of calcium in your blood. Report any signs of extremely low blood calcium such as muscle aches, cramps, or tingling in the hands and feet to your doctor immediately.

Low blood pressure: Blood pressure may occasionally drop when taking Sensipar (Cinacalcet). Be alert for any lightheadedness, dizziness, or a faster-than-normal heart rate. Move slowly when moving from a lying to an upright position. If your blood pressure drops too low, your doctor may adjust your dose or try another medication.

Liver disease: If you have reduced liver function, discuss with your doctor how Sensipar (Cinacalcet) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Sensipar (Cinacalcet), and whether any special monitoring is needed.

Seizures: Sensipar (Cinacalcet) may increase the possibility of seizures occurring, particularly if you have a history of seizures. If you have a seizure disorder or a history of seizures, discuss with your doctor how Sensipar (Cinacalcet) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Pregnancy: Sensipar (Cinacalcet) should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking Sensipar (Cinacalcet), contact your doctor immediately.

Breast-feeding: It is not known if Sensipar (Cinacalcet) passes into breast milk. If you are a breast-feeding mother and are taking Sensipar (Cinacalcet), it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using Sensipar (Cinacalcet) have not been established for children.