Cladribine: uses, dosing, side effects & brands
Cladribine is a purine antimetabolite sold in the U.S. under one brand, for hairy cell leukemia, non-hodgkin lymphoma and multiple sclerosis. Below: what the FDA label says, every product that contains it, what the pills look like, and its recall record.
Key facts
- Drug class
- Purine Antimetabolite
- Treats
- Hairy Cell Leukemia, Non-Hodgkin Lymphoma and Multiple Sclerosis
- Available as
- Tablet
- Sold as
- Mavenclad
- Prescription?
- Prescription only
- Generic available?
- Not in our catalog
- Boxed warning
- Boxed warning
How cladribine is dosed
From the FDA label for Mavenclad (application NDA022561). Other cladribine products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.
Assessments are required prior to starting each MAVENCLAD treatment course. ( 2.1 ) Cumulative dosage of 3.5 mg/kg administered orally and divided into 2 treatment courses (1.75 mg/kg per treatment course). Each treatment course is divided into 2 treatment cycles. ( 2.2 ) MAVENCLAD is a cytotoxic drug. ( 2.4 ) Separate administration from any other oral drug by at least 3 hours. ( 2.4 ) 2.1 Assessments Prior to Starting Each MAVENCLAD Treatment Course Cancer Screening Follow standard cancer screening guidelines because of the risk of malignancies [see Boxed Warning and Warnings and Precautions (5.1) ] . Pregnancy Exclude pregnancy prior to treatment with MAVENCLAD in females of reproductive potential [see Contraindications (4) , Warnings and Precautions (5.2) , and Use in Specific Populations (8.1 , 8.3) ] . Complete Blood Count (CBC) Obtain a CBC with differential including lymphocyte count [see Dosage and Administration (2.5) and Warnings and Precautions (5.3) ] . Lymphocytes must be: within normal limits before initiating the first treatment course at least 800 cells per microliter before initiating the second treatment course If necessary, delay the second treatment course for up to 6 months to allow for recovery of lymphocytes to at least 800 cells per microliter. If this recovery takes more than 6 months, the patient should not receive further treatment with MAVENCLAD.…
Cladribine side effects
The following serious adverse reactions and potential risks are discussed, or discussed in greater detail, in other sections of the labeling: Malignancies [see Warnings and Precautions (5.1) ] Risk of Teratogenicity [see Warnings and Precautions (5.2) ] Lymphopenia [see Warnings and Precautions (5.3) ] Infections [see Warnings and Precautions (5.4) ] Hematologic Toxicity [see Warnings and Precautions (5.5) ] Graft-Versus-Host Disease With Blood Transfusion [see Warnings and Precautions (5.6) ] Liver Injury [see Warnings and Precautions (5.7) ] Hypersensitivity [see Warnings and Precautions (5.8) ] Cardiac Failure [see Warnings and Precautions (5.9) ] Most common adverse reactions (incidence > 20%) are upper respiratory tract infection, headache, and lymphopenia. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact EMD Serono at 1-800-283-8088 ext. 5563 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical studies are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical studies of another drug and may not reflect the rates observed in practice. In the clinical trial program of cladribine in MS, 1,976 patients received cladribine for a total of 9,509 patient years. The mean time on study including follow-up was approximately…
Who shouldn’t take cladribine
MAVENCLAD is contraindicated: in patients with current malignancy [see Warnings and Precautions (5.1) ]. in pregnant women and in females and males of reproductive potential who do not plan to use effective contraception during MAVENCLAD dosing and for 6 months after the last dose in each treatment course for females, and 14 weeks for males. May cause fetal harm [see Warnings and Precautions (5.2) and Use in Specific Populations (8.1 , 8.3) ] . in patients infected with the human immunodeficiency virus (HIV ) [see Warnings and Precautions (5.4) ]. in patients with active chronic infections (e.g., hepatitis or tuberculosis) [see Warnings and Precautions (5.4) ]. in patients with a history of hypersensitivity to cladribine [see Warnings and Precautions (5.8) ]. in females intending to breastfeed on a MAVENCLAD treatment day and for 10 days after the last dose [see Use in Specific Populations (8.2) ]. Patients with current malignancy. ( 4 ) Pregnant women, and females and males of reproductive potential who do not plan to use effective contraception during MAVENCLAD dosing and for 6 months after the last dose in each treatment course for females, and 14 weeks for males. ( 4 , 8.3 ) HIV infection. ( 4 ) Active chronic infections (e.g., hepatitis or tuberculosis). ( 4 ) History of hypersensitivity to cladribine. ( 4 , 5.8 ) Females intending to breastfeed on a MAVENCLAD treatment day and for 10 days after the last dose. ( 4 , 8.2 )
Cladribine drug interactions
Table 3 Drug Interactions with MAVENCLAD 7.1 Immunomodulatory, Immunosuppressive, or Myelosuppressive Drugs Clinical Impact Concomitant use of MAVENCLAD with immunomodulatory, immunosuppressive, or myelosuppressive drugs may increase the risk of adverse reactions because of the additive effects on the immune system [see Warnings and Precautions (5.4) ] . Prevention or Management Concomitant use with myelosuppressive or other immunosuppressive drugs is not recommended. Acute short- term therapy with corticosteroids can be administered. In patients who have previously been treated with immunomodulatory or immunosuppressive drugs, consider potential additive effect, the mode of action, and duration of effect of the other drugs prior to initiation of MAVENCLAD. 7.2 Interferon-Beta Clinical Impact Concomitant use of MAVENCLAD with interferon-beta did not change the exposure of cladribine to a clinically significant effect; however, lymphopenia risk may be increased [see Warnings and Precautions (5.3) ]. Prevention or Management Concomitant use is not recommended. 7.3 Hematotoxic Drugs Clinical Impact Concomitant use of MAVENCLAD with hematotoxic drugs may increase the risk of adverse reactions because of the additive hematological effects [see Warnings and Precautions (5.5) ]. Prevention or Management Monitor hematological parameters. 7.4 Antiviral and Antiretroviral Drugs Clinical Impact Compounds that require intracellular phosphorylation to become active (e.g., lamivudine, zalcitabine, ribavirin, stavudine, and zidovudine) could interfere with the intracellular phosphorylation and activity of cladribine. Prevention or Management Avoid concomitant use . 7.5 Potent ENT, CNT and BCRP Transporter Inhibitors Clinical Impact Cladribine is a substrate of breast cancer resistance protein (BCRP), equilibrative nucleoside (ENT1), and concentrative nucleoside (CNT3) transport proteins. The bioavailability, intracellular distribution, and renal elimination of cladribine may be altered by potent ENT1, CNT3, and BCRP transporter inhibitors. Prevention or Management Avoid co-administration of potent ENT1, CNT3, or BCRP transporter inhibitors (e.g., ritonavir, eltrombopag, curcumin, cyclosporine, dilazep, nifedipine, nimodipine, cilostazol, sulindac, dipyridamole, or reserpine) during the 4 to 5 day MAVENCLAD treatment cycles. If this is not possible, consider selection of alternative concomitant drugs with no or minimal ENT1, CNT3, or BCRP transporter inhibiting properties. If this is not possible, dose reduction to the minimum mandatory dose of drugs containing these compounds, separation in the timing of administration, and careful patient monitoring is recommended. 7.6 Potent BCRP and P-gp Transporter Inducers Clinical Impact Possible decrease in cladribine exposure if potent BCRP or P-gp transporter inducers are co-administered. Prevention or Management Consider a possible decrease in cladribine efficacy if potent BCRP (e.g., corticosteroids) or P-gp (e.g., rifampicin, St. John's Wort) transporter inducers are co-administered. Immunosuppressive drugs: Consider overlapping effects on immune system, when used sequentially. Concomitant use not recommended. ( 7.1 ) Hematotoxic drugs: Monitor patients for additive effects on the hematological profile. ( 7.3 ) Antiviral and antiretroviral drugs: Avoid concomitant use. ( 7.4 ) BCRP or ENT/CNT inhibitors: May alter bioavailability of cladribine. Avoid concomitant use. ( 7.5 )
Every cladribine product we track (1)
Same active ingredient — different manufacturer, form, price and FDA recall record. That last one is what our independent score measures.
Only one: Mavenclad.
What cladribine pills look like
Imprint codes, colour and shape from the FDA’s labelling data. Match the imprint on your pill — or search any imprint.
Can you crush or split cladribine?
At least one cladribineproduct is labelled to be swallowed whole — crushing an extended-release tablet releases the whole day’s dose at once. Which applies depends on the form you were given.
What each cladribine label says about crushing, splitting and chewingHow long cladribine keeps
No cladribine label we read sets a separate limit for after opening, but they do specify how it must be stored — and the stability behind any date assumes those conditions.
Does cladribine expire? The in-use limits and storage rules from its labelsCladribine and breastfeeding
From LactMed, the US National Library of Medicine’s Drugs and Lactation Database — quoted, not rewritten.
Full LactMed record for cladribine: levels in milk, effects in breastfed infants, and the drugs it would consider insteadThe amount of cladribine in milk is low with oral doses of 10 to 20 mg daily used in multiple sclerosis. Data in one patient indicates that the drug is rapidly eliminated over 24 hours and undetectable at 48 hours after a dose. Manufacturers recommend a 7-day (Europe) or 10-day (US) breastfeeding abstinence period after a dose. Chemotherapy may adversely affect the normal microbiome and chemical makeup of breastmilk. Women who receive chemotherapy during pregnancy are more likely to have difficulty nursing their infant.
National Institute of Child Health and Human Development, record revised June 15, 2025. LactMed states its information is not a substitute for professional judgement.
What people report to the FDA about cladribine
The FDA Adverse Event Reporting System (FAERS) collects reports from patients and clinicians. It holds 2,685 reports naming cladribine, and the FDA flagged 94% of those reports as serious. The effects reported most often — leaving out reports about overdose, misuse or the condition being treated, which dominate the raw list for common medicines:
- febrile neutropenia207 reports
- pyrexia189 reports
- pancytopenia156 reports
- neutropenia154 reports
- thrombocytopenia126 reports
- pneumonia106 reports
- rash maculo-papular93 reports
- lymphopenia86 reports
Read these as a signal, not a rate. A report does not mean cladribine caused the effect — anyone can file one, and many describe people taking several medicines for several conditions. Crucially there is no denominator: FAERS does not record how many people took the drug, so these counts cannot be turned into “X% of patients” — a bigger number often just means a more widely used or more talked-about drug. Duplicates exist, and publicity drives reporting. For what is actually established, read the FDA label section above.
Source: openFDA drug/event (FAERS), retrieved July 25, 2026.
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Frequently asked questions
What is cladribine?
Mavenclad (Cladribine) is a purine antimetabolite used to treat Hairy Cell Leukemia, Non-Hodgkin Lymphoma, Multiple Sclerosis, B-Cell Chronic Lymphocytic Leukemia.
What kind of drug is cladribine?
The FDA classifies cladribine as a purine antimetabolite. If you are checking whether it is safe to combine with something else, the class is what matters — two drugs from the same class usually should not be stacked.
Can you take cladribine with other medicines?
It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run cladribine against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.
What forms does cladribine come in?
Across the brands we track, cladribine is currently marketed as tablet, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.
Is there a generic cladribine?
We do not currently list a generic-labelled cladribine product. That does not always mean none exists — it means none appears under a generic name in the FDA data we track. Ask your pharmacist.
Cite this page
- APA
- pharmaranks. (2026, July 24). Cladribine: uses, dosing, side effects & brands. https://pharmaranks.com/drugs/cladribine
- MLA
- “Cladribine: uses, dosing, side effects & brands.” pharmaranks, 24 July 2026, https://pharmaranks.com/drugs/cladribine.
We summarise public FDA and NIH sources — for a clinical claim, cite the primary source we link to as well.
Sources: FDA openFDA drug label, National Drug Code Directory, and Enforcement (recall) database. This page reproduces public FDA data and is not medical advice. Dosing is set by your prescriber.
Read the full FDA label for cladribine on DailyMed (NIH) ↗ — including its boxed warning in full.