UNIFOL

Indications

• Folate deficiency
• Rescue therapy following high-dose methotrexate therapy
• Treatment of megaloblastic anemia due to folate deficiency
• Adjunct therapy in certain types of cancer treatment

Dosage

Children: Refer to BNF for Children for specific dosage guidelines based on condition and age.

Adults: Refer to BNF for specific dosage guidelines based on condition and setting.

Mechanism of action

Folinic acid acts by providing an active form of folate that bypasses the metabolic block caused by drugs such as methotrexate. It is converted into tetrahydrofolate, which is necessary for the synthesis of purines and pyrimidines, essential for DNA and RNA production. This action helps to restore normal folate levels in cells and counteract the effects of folate antagonists.

Pharmacodynamics

Folinic acid exhibits its pharmacological effects mainly by enhancing the availability of folate, promoting the synthesis of nucleotides necessary for cell division and growth. It has a protective effect on rapidly dividing cells, particularly in the bone marrow and gastrointestinal tract, where toxicity from chemotherapeutic agents can lead to significant adverse effects.

Pharmacokinetics

Folinic acid is administered orally or intravenously, with absorption occurring in the small intestine. It is widely distributed in body tissues and can cross the blood-brain barrier. The elimination half-life is approximately 6 to 12 hours, with excretion primarily occurring via urine as metabolites. It is important to note that the pharmacokinetics may vary based on the route of administration and the presence of other medications.

Contra-indications

• Hypersensitivity to folinic acid or any component of the formulation
• Untreated pernicious anemia or other megaloblastic anemias due to vitamin B12 deficiency

Adverse effects

• Allergic reactions including rash, pruritus, and anaphylaxis
• Gastrointestinal disturbances such as nausea, vomiting, and diarrhea
• Neurological effects including seizures and confusion in rare cases

Interactions

• May enhance the efficacy of fluorouracil and other antimetabolites
• Potential antagonism with methotrexate; monitor closely if co-administered

Precautions

• Use with caution in patients with a history of hypersensitivity
• Monitor hematologic parameters in patients receiving folinic acid for prolonged periods
• Consider vitamin B12 levels before initiation in patients with megaloblastic anemia

Pregnancy

Folinic acid is generally considered safe during pregnancy and may be used to prevent neural tube defects.

Breast-feeding

Folinic acid is excreted in breast milk, but is considered safe. Adequate maternal intake of folate is recommended.

Storage

Store in a cool, dry place away from light. Protect from moisture. Keep out of reach of children.

Formulations

• Oral tablets
• Injectable solution