It is administered intramuscularly or intravenously.
When administered intravenously in one minute, no more than 160 mg of calcium folinate should be administered because of the calcium present in the solution.
Before use with the intravenous route of administration calcium folinate can be diluted with 0.9% solution of sodium chloride or 5% solution of dextrose.
When preparing the injection solution calcium folinate can be diluted with Ringer's solution, Ringer's solution with lactate, 10% dextrose solution, 5% dextrose solution, 0.9% sodium chloride solution to a concentration of 0.06 mg / ml to 1 mg / ml. The resulting solution remains stable for 24 hours. Discard the residue.
Due to the fact that different schemes of calcium folinate are used, the doctor should be guided by special medical literature when choosing a specific dose.
Prevention of toxic effects of methotrexate when used in high doses
The following recommendations can serve as a guide for the determination of doses and the scheme of calcium folinate in adults, elderly patients (≥65 years) and children. Prevention of toxic effects of methotrexate, used in high doses,is carried out by parenteral administration in patients with malabsorption syndrome or other pathology of the digestive tract, when intestinal absorption may be difficult. Doses of 25-50 mg should be administered parenterally due to saturable absorption of calcium folinate in the intestine.
The dose and duration of calcium folinate, first of all, depend on the scheme of therapy and doses of methotrexate, the appearance of signs of toxicity and individual features of excretion of methotrexate. Typically, the first dose of calcium folinate is 15 mg (6-12 mg / m2), the introduction begins 12-24 hours (not later than 24 hours) after the start of infusion of methotrexate. The same dose is administered every 6 hours for 72 hours. After parenteral administration of several doses of the drug, you can switch to the use of oral forms of calcium folinate.
In addition to the introduction of calcium folinate in the prevention of toxic effects of methotrexate, used in high doses, are activities that accelerate the excretion of methotrexate (providing enhanced diuresis and alkalinization of urine). The kidney function should be monitored daily by measuring the concentration of serum creatinine.It is recommended to measure the concentration of methotrexate in the blood serum 48 hours after the start of the infusion. If the residual concentration of methotrexate is more than 0.5 μmol / l, correction of the calcium dosing regimen of folinate is necessary.
The recommended correction of calcium folate therapy in the prevention of toxic effects of methotrexate, used in high doses, depending on its residual concentration
| The residual concentration of methotrexate in the blood after 48 hours after the onset of methotrexate | The dose of calcium folinate, applied every 6 hours for 48 hours or until the concentration of methotrexate is lower than 0.05 μmol / l |
| ≥ 0.5 μmol / l | 15 mg / m2 |
| ≥ 1.0 μmol / l | 100 mg / m2 |
| ≥ 2.0 μmol / l | 200 mg / m2 |
Cytotoxic therapy in combination with fluorouracil
Various doses and schemes of calcium folinate are used.
Below are examples of calcium folinate administration regimens that have been used in adults and elderly patients with colorectal cancer.
Weekly mode: calcium folinate in a dose of 20 mg / m2 administered intravenously bolus or in a dose of 200-500 mg / m2 infuzionno within 2 hours and a bolus of fluorouracil in a dose of 500 mg / m2 in the middle or at the end of calcium folinate infusion.
Monthly mode: calcium folinate in a dose of 20 mg / m2 administered intravenously bolus or in a dose of 200-500 mg / m2 infuzionno for 2 hours, followed by bolus injection of fluorouracil at a dose of 425 mg / m2 or 370 mg / m2 for 5 consecutive days.
Two-month mode: intravenous administration of calcium folinata in a dose of 200 mg / m2 for 2 hours, followed by bolus injection of fluorouracil at a dose of 400 mg / m2 and a 22-hour infusion of fluorouracil at a dose of 600 mg / m2 for 2 consecutive days every 2 weeks.
The therapy should be stopped with the number of leukocytes and blood platelets of less than 3.5 thousand and 100.0 thousand, respectively. Also, therapy should be discontinued if bleeding occurs from the gastrointestinal tract, severe diarrhea (≥7 times per day), exfoliative dermatitis.
Depending on the patient's condition, clinical response and manifestations of toxicity of therapy, fluorouracil dose adjustment may be required (see the instructions for using fluorouracil). A decrease in the dose of calcium folinate is not required.
The number of repeated cycles is at the discretion of the attending physician.
Intoxication with folic acid antagonists (methotrexate, trimethoprim, pyrimethamine)
Methotrexate overdose
In case of an accidental overdose of methotrexate, the drug is administered at a dose equal to or greater than the dose of methotrexate administered no later than 1 hour after methotrexate injection, then the drug is injected every 3 hours at 10 mg / m2 until the disappearance of signs of toxicity.
Toxicity of trimethoprim
After stopping the administration of trimethoprim, calcium folinate in a dose of 3-10 mg / day until the recovery of the parameters of a clinical blood test.
The toxicity of pyrimethamine
In the case of high doses of pyrimethamine or a prolonged period of treatment with low doses, calcium folinate in a dose of 5-50 mg / day, depending on the parameters of a clinical blood test.
In the treatment of megaloblastic anemia, caused by a deficiency of folic acid, the drug is used in a dose of 5 mg (maximum to 15 mg) per day.