Fusilev Side Effects Center

Last updated on RxList: 1/4/2021
Fusilev Side Effects Center

Medical Editor: John P. Cunha, DO, FACOEP

What Is Fusilev?

Fusilev (levoleucovorin) is a derivative of folic acid indicated for the treatment of metastatic colorectal cancer and bone cancer (after methotrexate therapy).

What Are Side Effects of Fusilev?

Common side effects of Fusilev include:

Seizures and fainting, though rare, have been reported in patients taking Fusilev.

Dosage for Fusilev

Fusilev rescue at a dose of 7.5 mg (approximately 5 mg/m2) every 6 hours for 10 doses starts 24 hours after the beginning of the methotrexate infusion.

What Drugs, Substances, or Supplements Interact with Fusilev?

Fusilev may interact with sulfa drugs, seizure medications, or multivitamin or mineral supplements that contain folic acid. Tell your doctor all medications and supplements you use.

Additional Information

Our Fusilev Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

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.


Skin Cancer Symptoms, Types, Images See Slideshow
Fusilev Consumer Information

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

Tell your doctor or caregivers at once if you have:

  • blisters or ulcers in your mouth, red or swollen gums, trouble swallowing;
  • severe or ongoing diarrhea;
  • a light-headed feeling, like you might pass out;
  • seizure (convulsions);
  • dehydration symptoms--feeling very thirsty or hot, being unable to urinate, heavy sweating, or hot and dry skin; or
  • kidney problems--little or no urination; painful or difficult urination; swelling in your feet or ankles.

Common side effects may include:

  • diarrhea, nausea, vomiting; or
  • pain or sores in your mouth.

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.

Read the entire detailed patient monograph for Fusilev (Levoleucovorin Injection)

Fusilev Professional Information


The following clinically significant adverse reactions are described elsewhere in the labeling:

  • Hypercalcemia [see WARNINGS AND PRECAUTIONS]
  • Increased gastrointestinal toxicities with fluorouracil [see WARNINGS AND PRECAUTIONS]

Clinical Trials Experience

Because clinical trials 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 trials of another drug and may not reflect the rates observed in practice.

High-Dose Methotrexate Therapy

Table 2 presents the frequency of adverse reactions which occurred during the administration of 58 courses of high-dose methotrexate 12 grams/m2 followed by Fusilev rescue for osteosarcoma in 16 patients aged 6 to 21 years. Most patients received Fusilev 7.5 mg every 6 hours for 60 hours or longer, beginning 24 hours after completion of methotrexate administration.

Table 2 Adverse Reactions with High-Dose Methotrexate Therapy

Adverse ReactionsFusilev
n = 16
All Grades (%)Grades 3-4 (%)
Skin and Appendages
Renal function abnormal60
Taste perversion60

Combination With Fluorouracil In Colorectal Cancer

Table 3 presents the frequency of adverse reaction which occurred in 2 arms of a randomized controlled trial conducted by the North Central Cancer Treatment Group (NCCTG) in patients with metastatic colorectal cancer. The trial failed to show superior overall survival with fluorouracil + levoleucovorin compared to fluorouracil + d,l-leucovorin. Patients were randomized to fluorouracil 370 mg/m2 intravenously and levoleucovorin 100 mg/m2 intravenously, both daily for 5 days, or to fluorouracil 370 mg/m2 intravenously and d,l-leucovorin 200 mg/m2 intravenously, both daily for 5 days. Treatment was repeated week 4 and week 8, and then every 5 weeks until disease progression or unacceptable toxicity.

Table 3 Adverse Reactions Occurring in ≥ 10% of Patients in Either Arm

Adverse ReactionLevoleucovorin/ fluorouracil
d,l-Leucovorin/ fluorouracil
Grades 1-4
Grades 3-4
Grades 1-4
Grades 3-4
Gastrointestinal Disorders
Abdominal Pain1143193
General Disorders
Skin Disorders
Metabolism and Nutrition
Anorexia/Decreased Appetite244252
1 Includes abdominal pain, upper abdominal pain, lower abdominal pain, and abdominal tenderness

Postmarketing Experience

The following adverse reaction have been identified during postapproval use of levoleucovorin products. Because these reactions are reported from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

Dermatologic: pruritus, rash

Respiratory: dyspnea

Other: temperature change, rigors, allergic reactions

Read the entire FDA prescribing information for Fusilev (Levoleucovorin Injection)

© Fusilev Patient Information is supplied by Cerner Multum, Inc. and Fusilev Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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