Indications 

Leucovorin is a prescription medicine indicated to mitigate the toxicity and counter the consequences of impaired elimination of methotrexate, a cancer medicine given in high doses.  

Leucovorin is also used to reduce the side effects of inadvertent overdoses of folic acid antagonists such as methotrexate (Rheumatrex), pyrimethamine (Daraprim), trimethoprim (Trimpex, Proloprim), and others. 

Leucovorin belongs to a category of drugs known as folic acid analogs. Its mechanism of action entails safeguarding healthy cells against the harmful effects of methotrexate or related medications while enabling methotrexate to enter and exterminate cancer cells. 

Uses and Dosage 

Before using Leucovorin, and with every subsequent refill, carefully review its medication guide and patient information leaflet. Do not hesitate to consult with your physician or pharmacist for any questions or clarifications. 

The dosage and length of the intake of Leucovorin are based on the patient’s medical condition and response to the treatment.  

Typically, Leucovorin is taken every 6 hours or once daily as prescribed by the doctor without regard to food intake. In cases of inadvertent overdose, prompt initiation of this medication is crucial to achieving optimal therapeutic outcomes.  

Leucovorin is usually administered concomitantly with other medications to enhance renal elimination of methotrexate, and intravenous fluids may also be employed to prevent dehydration. 

To achieve optimal results, take Leucovorin regularly around the same time daily as prescribed. Refrain from taking more or less of it or more frequently than your doctor prescribes. 

Side Effects 

Common Side Effects

Severe adverse reactions with Leucovorin are infrequent, but the common side effects listed below may still occur. Notify your physician or pharmacist immediately if any of these symptoms persist or worsen. 

• Facial flushing 
• Nausea 
• Vomiting 

Allergic Reactions 

While the chances of a severe allergic reaction to Leucovorin are low, prompt medical attention should be sought if it occurs. Indications of a serious allergic response may involve the following: 

• Rash 
• Facial, tongue, or throat itching or swelling 
• Difficulty breathing 
• Intense dizziness 

The side effects of Leucovorin listed here are not complete. If any unmentioned side effects occur and cause discomfort, inform your doctor immediately. 

Cautions 

Before starting treatment with Leucovorin, inform your physician or pharmacist of any known hypersensitivities, particularly to leucovorin, levoleucovorin, folic acid (Folicet, present in multivitamins), and any other drugs. 

This medication may contain inactive ingredients that may trigger allergic reactions or other problems. Request a list of the ingredients from your pharmacist. 

To ensure Leucovorin is safe for you, disclose your medical history to your doctor, especially of: 

• Liver disease 
• Kidney disease 
• Respiratory disorders 
• Dehydration 

Disclose to your physician if you have anemia resulting from vitamin B12 deficiency or an inability to absorb vitamin B12. Leucovorin should not be taken to treat this form of anemia. 

Inform your doctor and pharmacist about all prescription and nonprescription medications, vitamins, supplements, and herbal products you are currently taking or planning to take.  

Specifically, mention if you are taking any of the medications listed below, for they may need to adjust your medication doses or monitor you closely for side effects. 

• Medications for seizures: 
• Phenobarbital 
• Phenytoin (Dilantin) 
• Primidone (Mysoline) 
• Trimethoprim-sulfamethoxazole (Bactrim, Septra) 

Avoid taking medications that contain levoleucovorin while taking Leucovorin, as the two medications are very similar. 

Leucovorin’s potential for causing fetal harm or affecting reproductive capacity in pregnant women is unknown. Therefore, it should only be given to a pregnant woman if it is clearly needed. 

There is uncertainty about whether calcium folinate is passed into human breast milk. As a precaution, consult your healthcare provider before nursing an infant while taking this medication.