Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes Mavenclad (Cladribine). If you are concerned about side effects, discuss the risks and benefits of Mavenclad (Cladribine) with your doctor.

The following side effects have been reported by at least 1% of people taking Mavenclad (Cladribine). Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• back pain
• Cold Sores
• cold symptoms (e.g., fatigue, nasal congestion, cough, sore throat)
• Diarrhea
• hair loss or thinning
• headache
• nausea
• rash
• toothache
• vomiting

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• abdominal pain
• anxiety
• Fever
• flu and flu-like symptoms (e.g., fatigue, sore throat, headache, fever, chills)
• symptoms of infection (e.g., unusual fatigue, fever, aches, pain, flu-like symptoms)
• symptoms of Shingles (e.g., "band" of severe pain, blistering rash, headache, burning, tingling, numbness or itchiness of the skin, general feeling of being unwell)
• symptoms of tuberculosis (e.g., persistent cough, fever, weight loss)
• vaginal yeast infection (e.g., itching, white, curd-like discharge)

Stop taking the medication and seek immediate medical attention if any of the following occur:

• symptoms of progressive multifocal leukoencephalopathy (PML) (e.g., worsening weakness on one side of the body, clumsiness, vision changes, confusion, personality changes)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking Mavenclad (Cladribine).

Each round, white, biconvex tablet, engraved with 'C' on one side and '10' on the other side contains 10 mg of Mavenclad (Cladribine). Nonmedicinal ingredients: hydroxypropyl betadex, sorbitol and magnesium stearate.

Do not take Mavenclad (Cladribine) if you:

• are allergic to Mavenclad (Cladribine) or any ingredients of the medication
• are at an increased risk of developing infections
• have a disease that reduces the effectiveness of the immune system
• taking other medications that suppress the immune system
• are breast-feeding
• are pregnant
• have a history of progressive multifocal leukoencephalopathy (PML)
• have active cancer
• have moderate to severely decreased kidney function
• have severe active or long-term infections caused by bacteria, viruses or fungi (e.g., hepatitis, Tuberculosis)

There may be an interaction between Mavenclad (Cladribine) and any of the following:

• Azathioprine
• BCG (bacillus Calmette-Guérin)
• cancer medications (e.g., Carboplatin, Cyclophosphamide, Doxorubicin, Ifosfamide, Pimecrolimus, Vincristine)
• Clozapine
• corticosteroids (e.g., budesonide, Dexamethasone, Hydrocortisone, fluticasone, Prednisone)
• Cyclosporine
• Deferiprone
• echinacea
• Hydroxyurea
• Imiquimod
• Leflunomide
• monoclonal antibodies (e.g., Belimumab, eculizumab, Infliximab, Natalizumab, Ocrelizumab, Rituximab)
• mycophenolate
• Roflumilast
• Tacrolimus
• Tofacitinib
• vaccines

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with Mavenclad (Cladribine). Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the Nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.

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 Mavenclad (Cladribine).

Birth Control: Mavenclad (Cladribine) should not be used during pregnancy. Women of childbearing age who are taking Mavenclad (Cladribine) and female partners or men who are taking Mavenclad (Cladribine) should use an effective method of birth control during treatment and for at least 6 months after the last dose of the medication. It is not known if Mavenclad (Cladribine) will make birth control pills less effective. If you are using birth control pills, a barrier method of contraception (e.g., condoms) should be added during treatment and for at least 4 weeks after the last dose in each treatment year. If you become pregnant while taking Mavenclad (Cladribine), contact your doctor immediately.

Cancer: As with other medications that reduce the effectiveness of the immune system, Mavenclad (Cladribine) may increase the risk of developing certain types of cancer. Discuss any concerns you may have with your doctor. Report any unusual infections, swelling or persistent pain, or unintentional weight loss to your doctor as soon as possible.

Fructose intolerance: Mavenclad (Cladribine) contains sorbitol. If you have hereditary problems of fructose intolerance, you should not take Mavenclad (Cladribine).

Kidney function: Kidney Disease or reduced kidney function may cause Mavenclad (Cladribine) to build up in the body, causing side effects. If you have reduced kidney function or kidney disease, discuss with your doctor how Mavenclad (Cladribine) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Mavenclad (Cladribine), and whether any special monitoring is needed.

Progressive multifocal leukoencephalopathy (PML): There have been reports of PML after using Mavenclad (Cladribine). PML is a rare disorder that causes nerve damage in the brain. If you experience memory loss, vision loss, trouble thinking, or difficulty walking, contact your doctor immediately.

Serious infections: Mavenclad (Cladribine) affects the way your body's natural defences work to fight infection. This makes the body more likely to develop infections due to bacteria, viruses, and fungi. This effect is increased if you are taking Mavenclad (Cladribine) with other medications that reduce the body's ability to fight infection. For some people, these infections have been fatal. If you have a history of chronic or frequent infections, discuss with your doctor how Mavenclad (Cladribine) 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.

Contact your doctor right away if you notice symptoms of a serious infection, such as fever, chills, headache, flu-like symptoms, feeling tired, cough, blood in the sputum, shortness of breath, night sweats, weight loss, nausea, vomiting, diarrhea, frequency or burning while passing urine, redness or swelling of skin or joint, cold sores, tooth pain, or new or worsening pain in any part of the body.

Vaccinations: It is not known how effective vaccines may be after treatment with Mavenclad (Cladribine). Certain immunizations may be dangerous if given while receiving or shortly after receiving a treatment course of Mavenclad (Cladribine). Before starting treatment with this medication, check with your doctor to ensure your immunizations are up to date. Vaccinations, including vaccinatation against chicken pox or shingles, should be completed at least 6 weeks before starting to take Mavenclad (Cladribine).

Pregnancy: There is very little information about the effects of Mavenclad (Cladribine) on the mother or developing baby if Mavenclad (Cladribine) is taken during pregnancy. It must not be used if you are pregnant. If you become pregnant while taking this medication, contact your doctor immediately.

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

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

Seniors: People 65 years of age and over were not included in studies for Mavenclad (Cladribine). Because seniors are more likely to have decreased kidney or liver function, they may be more likely to experience side effects of Mavenclad (Cladribine).