Megafol - Dosage | Interactions | Side effects

This article was medically reviewed by M.Pharm, Marko Tanaskovic on August 12, 2018. To read more about an author, click here.

Megafol tablets contain 5mg of folic acid, which is also known as vitamin B9. It is used to treat megaloblastic anemia caused by vitamin B9 deficiency. It is also used during pregnancy in pregnant women who have folate deficiency or increased risk of neural tube defect.

Megafol can also be used for the prevention of folic acid deficiency in patients taking drugs that may affect vitamin B9 levels, such as anticonvulsants (e.g. phenytoin).


Megafol should not be used in patients with cancer as it may affect the efficacy of cancer treatment. Megafol can be used in patients with cancer only if the doctor considers that megaloblastic anemia in these patients could be a significant complication.

This drug is contraindicated in patients who have pernicious anemia caused by vitamin B12 deficiency, as it may obscure the symptoms but it cannot eliminate the risk of irreversible damage to the nervous system.

There are rare cases of folic acid allergy and patients who have a known allergic reaction to this vitamin, should not take this medicine.

Megafol, Pregnancy and Breastfeeding

Megafol tablets can be used during pregnancy in women who have an increased risk of developing a defect of the nerve tube (condition known as spina bifida), as well as in pregnant women who have a deficiency of vitamin B9. The use of these tablets during pregnancy reduces the risk of neural tube defects. You should use Megafol tablets during pregnancy only if your doctor recommends it.

It can also be used during breastfeeding if recommended by a doctor.


The recommended dose in the treatment of megaloblastic anemia caused by vitamin B9 deficiency, as well as in the treatment of drug-induced folate deficiency, is 5mg daily for 4 months. The dose may be increased up to 15mg daily.

For the prevention of neural tube defects during pregnancy, it is recommended to use 5mg daily during the first three months of pregnancy.

Children should use syrups rather than pills. The pediatrician will determine the right dosage amount for your child.

Always consult your doctor about the dose you need to use.


Megafol should not be used concurrently with the following medicines:

  • Antibiotics, such as chloramphenicol.
  • Medicines used to treat fungal infections, such as: cotrimoxazole.
  • Sulfasalazine - a medicine used to treat ulcerative colitis and Crohn's disease.
  • Methotrexate - a medicine used in the treatment of cancer, rheumatoid arthritis and severe psoriasis.
  • Medicines used to treat cancer, such as: fluorouracil and capecitabine. Megafol increases the effects of these drugs, which increases the risk of side effects.
  • Phenobarbital - a medicine used to treat epilepsy. Megafol reduces the concentration of phenobarbital in the blood, thereby reducing its effectiveness.

Tell your doctor about all the medicines you are taking.

Side effects

The following adverse effects have been reported:

  • Nausea.
  • Vomiting.
  • Flatulence.
  • Loss of appetite.
  • Difficulty breathing.
  • Tightness in the chest.
  • Wheezing.
  • Fever.
  • Weakness.

Tell your doctor if you are experiencing any side effects.

Information on this website are provided for educational purposes only and are not intended for medical advice, diagnosis or treatment.

If you have any concerns or questions about your health, you should always consult with a physician or other health-care professional.

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