Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
CLOFARABINE vs CLOLAR
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Clofarabine is a purine nucleoside antimetabolite that inhibits DNA synthesis by reducing intracellular deoxynucleotide triphosphate pools via inhibition of ribonucleotide reductase, and by terminating DNA chain elongation through incorporation into DNA, leading to apoptosis.
Clolar (clofarabine) is a purine nucleoside antimetabolite that inhibits DNA synthesis and RNA transcription. It is phosphorylated intracellularly to its active triphosphate form, which competes with adenosine triphosphate for incorporation into DNA, leading to chain termination and inhibition of DNA polymerase and ribonucleotide reductase, resulting in apoptosis.
Treatment of relapsed or refractory acute lymphoblastic leukemia (ALL) in pediatric patients aged 1 to 21 years,Off-label: Treatment of acute myeloid leukemia (AML), myelodysplastic syndromes (MDS)
FDA: Treatment of relapsed or refractory acute lymphoblastic leukemia (ALL) in pediatric patients aged 1 to 21 years.,Off-label: Treatment of acute myeloid leukemia (AML), myelodysplastic syndromes (MDS), chronic myeloid leukemia (CML) in blast crisis.
52 mg/m^2 intravenously over 2 hours daily for 5 consecutive days, repeated every 28 days.
5 mg/m2 intravenously over 2 hours daily for 5 consecutive days. Repeat every 28 days.
Terminal elimination half-life: 5.2 hours (range 4-6 hours) in adult patients; clinically, this supports a 5-day continuous infusion schedule
Terminal elimination half-life approximately 5.2 hours in patients with normal renal function; prolonged in renal impairment (up to 9.8 hours with Cr Cl <60 m L/min) and in elderly; clinical context: supports once-daily dosing adjustment for renal function.
Hepatic; primarily metabolized by deamination via cytidine deaminase to 6-ketoclofarabine, a major metabolite. Also undergoes phosphorylation intracellularly. CYP450 involvement is minimal.
Clofarabine is partially metabolized by deamination via cytidine deaminase (CDA) to inactive 6-keto-clofarabine. Approximately 50-60% of the drug is excreted unchanged in urine.
Renal: 49-60% as unchanged drug; biliary/fecal: minimal (<1%)
Renal: 50-60% as unchanged drug; biliary/fecal: minimal (<5%)
47% bound to plasma proteins (primarily albumin)
47% bound to human plasma proteins, primarily albumin.
Vd: 14.6 L/kg (range 10-20 L/kg); indicates extensive extravascular distribution and tissue binding
Central Vd approximately 172 L/m² (extensive tissue distribution); in L/kg: ~4.6 L/kg (assuming 70 kg patient with BSA 1.73 m²). Clinical meaning: indicates wide distribution into total body water and tissues, exceeding total body water.
IV: 100% (only IV route); oral: not approved
Intravenous: 100% (only route of administration); oral: not available (no oral formulation).
Clcr ≥ 60 m L/min: no adjustment; Clcr 30-59 m L/min: reduce dose to 39 mg/m^2; Clcr < 30 m L/min: not recommended (no data).
Cr Cl >= 60 m L/min: no adjustment. Cr Cl 30-59 m L/min: reduce dose by 20%. Cr Cl < 30 m L/min: contraindicated.
Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 25% (monitor toxicity); Child-Pugh C: not recommended (no data).
No specific guidelines; use caution in severe hepatic impairment (Child-Pugh class C) and consider dose reduction based on tolerability.
52 mg/m^2 intravenously over 2 hours daily for 5 days every 28 days (same as adult dosing per body surface area; safety and efficacy established in pediatric patients 1 year and older).
1-21 years: 5 mg/m2 IV over 2 hours daily for 5 days every 28 days; reduce dose by 50% in patients with renal impairment.
No specific dose adjustment based solely on age; monitor renal function closely due to increased risk of nephrotoxicity; use same dosing as adults with renal adjustment as per GFR.
No specific dose adjustment, but monitor renal function closely due to age-related decline and increased risk of toxicity.
Clofarabine causes severe bone marrow suppression, including neutropenia, anemia, thrombocytopenia, and increased risk of infection. Hemorrhage and severe infections have been reported. Monitor blood counts regularly.
WARNING: HEMATOLOGIC TOXICITY, INFECTION, AND HEPATIC TOXICITY. Clolar suppresses bone marrow function, causing severe neutropenia, thrombocytopenia, and anemia. Fatal infections have occurred. Hepatic toxicity, including hepatic failure and death, has been reported. Monitor blood counts and liver function frequently.
1) Myelosuppression: monitor CBCs; dose adjustment may be needed. 2) Infections: increased susceptibility. 3) Hemorrhagic cystitis: may occur; manage with hydration and monitoring. 4) Hepatic toxicity: monitor liver function tests; dose reduction in hepatic impairment. 5) Renal toxicity: monitor renal function; dose adjustment for creatinine clearance <60 m L/min. 6) Tumor lysis syndrome: hydrate and use prophylactic allopurinol. 7) Systemic inflammatory response syndrome (SIRS): monitor for signs; discontinue if occurs.
Bone marrow suppression: severe neutropenia, thrombocytopenia, and anemia require close monitoring. Infections: serious and fatal infections (bacterial, fungal, viral) may occur. Hepatic toxicity: elevation of liver enzymes, bilirubin, and hepatic veno-occlusive disease. Renal toxicity: increased creatinine, hematuria, and hemolytic uremic syndrome-like reactions. Cardiac toxicity: pericardial effusion, hypotension, and ventricular dysfunction. Tumor lysis syndrome. Hypersensitivity reactions. Use in pregnancy: embryo-fetal toxicity. Vaccination: avoid live vaccines.
Hypersensitivity to clofarabine or any component of the formulation; severe hepatic impairment (Child-Pugh class C); severe renal impairment (creatinine clearance <30 m L/min).
Absolute: Hypersensitivity to clofarabine or any component of the formulation. Relative: Severe hepatic impairment (bilirubin >3 mg/d L or transaminases >5x ULN). Severe renal impairment (creatinine clearance <30 m L/min).
Grapefruit and grapefruit juice may affect liver enzymes and should be avoided. No specific food restrictions, but avoid alcohol due to potential hepatotoxicity. Maintain adequate hydration; no other known food interactions.
No specific food interactions are documented. However, maintain adequate hydration to reduce risk of nephrotoxicity and tumor lysis syndrome. Avoid grapefruit and grapefruit juice as they may affect metabolism via CYP3A4 (theoretical concern, though clofarabine is primarily renally excreted).
Clofarabine is embryotoxic and teratogenic in animal studies. In humans, it is classified as Pregnancy Category D. First trimester exposure is associated with major congenital malformations including neural tube defects, skeletal anomalies, and cardiovascular defects. Second and third trimester exposure may cause fetal myelosuppression, intrauterine growth restriction, and premature delivery.
Clofarabine is contraindicated in pregnancy. Based on its mechanism of action (inhibitor of DNA synthesis) and animal studies, there is a high risk of fetal harm if administered during pregnancy. In the first trimester, there is a significant risk of embryolethality and teratogenicity (structural anomalies). In the second and third trimesters, fetal growth restriction and central nervous system damage may occur. Pregnancy must be excluded before initiation.
It is unknown whether clofarabine is excreted in human breast milk. Due to the potential for serious adverse reactions in nursing infants, breastfeeding is contraindicated during therapy and for at least 1 week after the last dose. M/P ratio is not available.
No data available on the excretion of clofarabine into breast milk or its effects on the nursing infant. Due to potential for serious adverse reactions (e.g., myelosuppression, gastrointestinal toxicity), breastfeeding is contraindicated during therapy and for at least 3 months after the last dose. M/P ratio is unknown.
No specific pharmacokinetic studies have been conducted in pregnant women. Dose adjustments based on pregnancy-induced physiologic changes (increased plasma volume, renal clearance) are not established. Use with caution; the lowest effective dose based on tolerability and clinical response is recommended. Close monitoring for toxicity is essential.
There are no established dose adjustments for clofarabine during pregnancy, as use is contraindicated. Physiological changes in pregnancy (e.g., increased plasma volume, altered renal clearance) may affect pharmacokinetics, but no dosing guidelines exist. If inadvertent exposure occurs, immediate discontinuation is recommended and the pregnancy should be managed by a maternal-fetal medicine specialist.
Clofarabine is a purine nucleoside antimetabolite used primarily in pediatric relapsed or refractory acute lymphoblastic leukemia (ALL). It is associated with significant myelosuppression; monitor absolute neutrophil count and platelets closely. Capillary leak syndrome and systemic inflammatory response syndrome (SIRS) are rare but serious adverse effects; consider prophylactic corticosteroids. Hepatic veno-occlusive disease (VOD) has been reported, especially in patients with prior stem cell transplant. Administer with adequate hydration and monitor for tumor lysis syndrome.
Clolar (clofarabine) is a purine nucleoside analog indicated for pediatric relapsed/refractory acute lymphoblastic leukemia. Key pearls: (1) Monitor for systemic inflammatory response syndrome (SIRS) and capillary leak syndrome; premedicate with corticosteroids. (2) Requires aggressive hydration and allopurinol for tumor lysis prophylaxis. (3) Dose reductions needed for renal impairment (Cr Cl < 60 m L/min). (4) Avoid live vaccines during and after treatment.
Clofarabine is a chemotherapy drug that may lower your blood cell counts, increasing risk of infection, bleeding, and fatigue.,Report any signs of infection (fever, chills, sore throat), unusual bleeding or bruising, or shortness of breath immediately.,Drink plenty of fluids (8-10 glasses per day) to prevent kidney problems and tumor lysis syndrome.,Avoid live vaccines and close contact with people who have recently received oral polio vaccine.,Use effective contraception during treatment and for at least 6 months after the last dose.,Do not breastfeed while taking clofarabine.,You may experience nausea, vomiting, or diarrhea; your doctor can prescribe medications to manage these symptoms.
Clolar is a chemotherapy drug used to treat a type of leukemia in children that has not responded to other treatments.,You may experience side effects like fever, nausea, vomiting, diarrhea, and skin rashes. Report any signs of infection or unusual bleeding.,Drink plenty of fluids as directed to prevent kidney problems. You may receive IV fluids before and after treatment.,Avoid vaccinations without doctor approval, as live vaccines are not safe during treatment.,This drug can cause severe reactions including organ inflammation and fluid retention; seek immediate medical help if you have difficulty breathing, rapid weight gain, or swelling.
"Clofarabine, a purine nucleoside antimetabolite used in hematologic malignancies, may reduce the metabolism of Eltrombopag, a thrombopoietin receptor agonist, via inhibition of UDP-glucuronosyltransferase (UGT) enzymes, particularly UGT1A1 and UGT1A3. This leads to increased systemic exposure of Eltrombopag, potentially elevating the risk of hepatotoxicity (e.g., elevated liver enzymes) and other adverse effects such as thrombosis. Clinical outcomes may include exacerbated liver injury, which is particularly concerning in patients with pre-existing hepatic impairment or those receiving other hepatotoxic agents."
"Concurrent use of clofarabine and mecamylamine may synergistically increase the risk of severe hypotension and syncope. Clofarabine is a purine nucleoside analog that can cause capillary leak syndrome and hypotension, while mecamylamine is a ganglionic blocker that inhibits sympathetic outflow, leading to orthostatic hypotension. The combined hypotensive effects may result in profound blood pressure reduction, dizziness, and potential falls, particularly in patients with impaired cardiovascular function."
"The combination of clofarabine and nifedipine may increase the risk of cardiotoxicity, particularly QT interval prolongation and left ventricular dysfunction. Clofarabine has been associated with pericardial effusion and cardiac tamponade, while nifedipine, a calcium channel blocker, can cause hypotension and reflex tachycardia, potentially compounding hemodynamic stress in patients with compromised cardiac function. Clinical outcomes may include arrhythmias, heart failure exacerbation, or sudden cardiac death, especially in patients with preexisting cardiovascular risk factors."
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about CLOFARABINE vs CLOLAR, answered by our medical review team.
CLOFARABINE is a Antineoplastic Agent that works by Clofarabine is a purine nucleoside antimetabolite that inhibits DNA synthesis by reducing intracellular deoxynucleotide triphosphate pools via inhibition of ribonucleotide reductase, and by terminating DNA chain elongation through incorporation into DNA, leading to apoptosis.. CLOLAR is a Antineoplastic Agent that works by Clolar (clofarabine) is a purine nucleoside antimetabolite that inhibits DNA synthesis and RNA transcription. It is phosphorylated intracellularly to its active triphosphate form, which competes with adenosine triphosphate for incorporation into DNA, leading to chain termination and inhibition of DNA polymerase and ribonucleotide reductase, resulting in apoptosis.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between CLOFARABINE and CLOLAR depend on the specific clinical indication. These are both Antineoplastic Agent agents and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of CLOFARABINE is: 52 mg/m^2 intravenously over 2 hours daily for 5 consecutive days, repeated every 28 days.. The standard adult dose of CLOLAR is: 5 mg/m2 intravenously over 2 hours daily for 5 consecutive days. Repeat every 28 days.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between CLOFARABINE and CLOLAR in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. CLOFARABINE is classified as Category C. Clofarabine is embryotoxic and teratogenic in animal studies. In humans, it is classified as Pregnancy Category D. First trimester exposure is associated with major congenital malf. CLOLAR is classified as Category C. Clofarabine is contraindicated in pregnancy. Based on its mechanism of action (inhibitor of DNA synthesis) and animal studies, there is a high risk of fetal harm if administered du. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.