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Generic Name: cysteamine (sis TEE a meen)
Brand Names: Cystagon, Procysbi

Medically reviewed on Oct 16, 2017

What is Procysbi?

Procysbi (cysteamine) works by reducing the amount of cystine (an amino acid) in the body.

Procysbi is used to treat nephropathic cystinosis (NEF-roe-PATH-ik SIS-tin-OH-sis), a rare genetic condition that causes a build-up of cystine in the kidneys and other organs. Too much cystine can cause kidney failure or other medical problems.

Procysbi is for use in adults and children who are at least 2 years old.

Important information

Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.

Before taking Procysbi

You should not use Procysbi if you are allergic to cysteamine or penicillamine.

To make sure Procysbi is safe for you, tell your doctor if you have:

  • any type of skin rash;

  • bone problems (including fractures);

  • epilepsy or other seizure disorder;

  • liver disease;

  • a history of low white blood cell (WBC) counts;

  • a history of depression, drowsiness, or nervous system disorder; or

  • a history of stomach ulcer, or bleeding in your stomach or intestines.

It is not known whether Procysbi will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

It is not known whether cysteamine passes into breast milk or if it could harm a nursing baby. You should not breast-feed while using this medicine.

Procysbi should not be given to a child younger than 2 years old without a doctor's advice.

How should I use Procysbi?

Take Procysbi exactly as prescribed by your doctor. Follow all directions on your prescription label. Your doctor may occasionally change your dose to make sure you get the best results. Do not take this medicine in larger or smaller amounts or for longer than recommended.

Take this medicine with fruit juice, but not grapefruit juice.

You may take Procysbi with or without food, but take it the same way each time. To take this medicine with food, eat only a small amount (1/2 cup) of food within 1 hour before or 1 hour after you take the medicine. To take Procysbi without food, take the medicine at least 30 minutes before or 2 hours after a meal.

Do not crush or chew a Procysbi capsule or the medicine inside it. Swallow the capsule whole.

If you cannot swallow a capsule whole, follow the patient instructions for mixing the medicine with certain foods. Food mixing instructions may be different from one brand of cysteamine to another. Carefully follow the directions for the specific brand you are using.

  • After mixing Procysbi with food or liquid, swallow it without chewing. Take the medicine within 30 minutes after mixing. Do not save the mixture for later use.

  • Procysbi also comes with instructions for giving the mixture through a gastronomy tube (12 French or larger). Follow these instructions very carefully.

  • You may also ask your doctor or pharmacist about the types of foods to mix with this medicine, and how to give the mixture for best results.

While using Procysbi, you may need frequent blood tests. Your skin and your bones may also need to be checked.

Cystinosis is often treated with a combination of drugs, including vitamin and mineral supplements. Use all medications as directed by your doctor. Read the medication guide or patient instructions provided with each medicine. Do not change your doses or medication schedule without your doctor's advice.

You should not stop using Procysbi without your doctor's advice. Stopping suddenly may make your condition worse.

Store at room temperature away from moisture, heat, and light.

What happens if I miss a dose?

Take the missed dose as soon as you remember.Skip the missed dose if your next dose is due in less than 4 hours.

Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking Procysbi?

Avoid eating high-fat foods within 1 hour before or 1 hour after you take Procysbi.

Do not drink alcohol while taking Procysbi. Dangerous side effects can occur when alcohol is combined with this medicine.

This medication may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.

Procysbi side effects

Get emergency medical help if you have any of these signs of an allergic reaction to Procysbi: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have any of these side effects (some of these may be caused by your cystinosis disorder and not by this medicine):

  • a seizure (convulsions);

  • unusual bruising or streaks on the skin;

  • the first sign of any skin rash, no matter how mild;

  • bloody or tarry stools, coughing up blood or vomit that looks like coffee grounds;

  • increased pressure inside the skull--severe headaches, ringing in your ears, dizziness, drowsiness, depressed mood, nausea, vision problems, pain behind your eyes;

  • severe skin reaction--fever, sore throat, swelling in your face or tongue, burning in your eyes, skin pain, followed by a red or purple skin rash that spreads (especially in the face or upper body) and causes blistering and peeling.

Common Procysbi side effects may include:

  • stomach pain, nausea, vomiting, loss of appetite, diarrhea;

  • unusual breath odor or skin odor;

  • headache, dizziness;

  • rash;

  • fever; or

  • tired feeling, lack of energy.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect Procysbi?

Take this medicine at least 1 hour before or 1 hour after taking any medicine that contains bicarbonate or carbonate.

Other drugs may interact with cysteamine, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use Procysbi only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.