What are cladribine tablets, and what are they used for?

The cladribine 10mg tablet is a prescription medicine used to treat relapsing forms of multiple sclerosis (MS), to include relapsing-remitting disease and active secondary progressive disease, in adults. Because of its safety profile, oral cladribine is generally used in people who have tried another MS medicine that they could not tolerate or that has not worked well enough. Cladribine tablets are not recommended for use in people with clinically isolated syndrome (CIS). It is not known if cladribine tablets are safe and effective in children under 18 years of age.

What are the side effects of cladribine tablets?

WARNING: Malignancies and birth defects

Cancer risk (malignancies)

Treatment with cladribine tablets may increase your risk of developing cancer. Talk to your healthcare provider about your risk of developing cancer if you receive cladribine tablets. You should follow your healthcare provider instructions about screening for cancer.

Birth defects

Cladribine tablets may cause birth defects if used during pregnancy. Females must not be pregnant when they start treatment with cladribine tablets or become pregnant during cladribine tablets dosing and within 6 months after the last dose of each yearly treatment course. Stop your treatment with cladribine tablets and call your healthcare provider right away if you become pregnant during treatment with cladribine tablets.

The most common side effects of cladribine tablets include:

Low blood cell counts: Low blood cell counts have happened and can increase your risk of infections during your treatment with cladribine tablets. Your healthcare provider will do blood tests before you start treatment with cladribine tablets, during your treatment with cladribine tablets, and afterward, as needed.

Serious infections such as:

Fatal cases of TB and hepatitis have happened with cladribine during clinical studies. Tell your healthcare provider right away if you get any symptoms of the following infection related problems or if any of the symptoms get worse, including:

  • fever
  • loss of appetite
  • aching painful muscles
  • burning, tingling, numbness or itchiness of the skin in the affected area
  • headache
  • skin blotches, blistered rash and severe pain
  • feeling of being generally unwell

Progressive multifocal leukoencephalopathy (PML): PML is a rare brain infection that usually leads to death or severe disability. Although PML has not been seen in MS patients taking cladribine tablets, it may happen in people with weakened immune systems. Symptoms of PML get worse over days to weeks. Call your healthcare provider right away if you have any new or worsening neurologic signs or symptoms of PML, that have lasted several days, including:

  • weakness on 1 side of your body
  • changes in your vision
  • loss of coordination in your arms and legs
  • changes in your thinking or memory
  • decreased strength
  • confusion
  • problems with balance
  • changes in your personality

Liver problems: Cladribine tablets may cause liver problems. Your healthcare provider should do blood tests to check your liver before you start taking cladribine tablets. Call your healthcare provider right away if you have any of the following symptoms of liver problems:

Allergic reactions (hypersensitivities): Cladribine tablets can cause serious allergic reactions. Stop your treatment with cladribine tablets and go to the closest emergency room for medical help right away if you have any signs or symptoms of allergic reactions. Symptoms of an allergic reaction may include:

Heart failure: Cladribine tablets may cause heart failure, which means your heart may not pump as well as it should. Call your healthcare provider or go to the closest emergency room for medical help right away if you have any signs or symptoms such as shortness of breath, a fast or irregular heart beat, or unusual swelling in your body. Your healthcare provider may delay or completely stop treatment with cladribine tablets if you have severe side effects.

These are not all the possible side effects of cladribine tablets. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.