Acidum folicum Richter: composition and dosage form
One tablet contains 5 mg or 15 mg of folic acid. Both strengths belong to the therapeutic range: the product information speaks of daily doses from 5 to 45 mg, whereas the vitamin supplements everyone knows are measured in fractions of a milligram. That difference of an order of magnitude explains why this is a medicine and not a food supplement.
Any regimen is built from the two strengths. The 5 mg tablet is convenient where the dose has to be set precisely and then tapered gently, the 15 mg where the count runs to tens of milligrams. The splitting rule is stated separately: daily doses above 15 mg are not taken at once but in 2–3 divided doses.
How Acidum folicum Richter works
Folic acid, also called pteroylglutamic acid, and the other folates with more glutamic acid residues act as coenzymes in the transfer of one-carbon groups — formyl, hydroxymethyl, methyl, formimino. These reactions are needed for the biosynthesis of purine and pyrimidine bases, that is, for the synthesis of DNA and RNA. In the body folic acid is converted into folinic acid (FH4), the actual active substance; clinically folinic acid is used when the activity of dihydrofolate reductase is suppressed by treatment with folic acid antimetabolites, above all methotrexate.
The vitamin's second line of work is homocysteine metabolism. Folic acid, cobalamin (vitamin B12) and pyridoxal phosphate (vitamin B6) take part in it together; folic acid serves as the methyl group donor in the conversion of homocysteine into methionine and thereby lowers the homocysteine concentration in the blood. Clinical studies confirmed that a high homocysteine level is an independent risk factor for circulatory diseases associated with atherosclerosis, but the role of folic acid itself in preventing them still requires confirmation in further, well-designed studies. The wording here is cautious and worth remembering: the fall in the marker is proven, the benefit of that fall is not.
Indications
There is a single indication, but with a long list of situations: prevention and treatment of folic acid deficiency in the body in the following states and diseases.
- chronic diseases associated with haemolysis of the blood: thalassaemias, sickle cell anaemia, malaria;
- megaloblastic anaemia;
- chronic malnutrition;
- alcoholism;
- treatment with dialysis;
- taking certain medicines: barbiturates, primidone, ciclosporin, sulfasalazine, trimethoprim;
- use of oral contraceptives in women.
The list looks mixed, but behind it lies one and the same mechanism in three variants. Either the vitamin is used up faster than usual — as happens in chronic haemolysis, when the bone marrow is forced to build new red cells without pause. Or little of it arrives: in chronic malnutrition and in alcoholism. Or it is lost, or its conversion is disturbed by outside interference: in dialysis and while taking the medicines listed. That last point is worth remembering, because almost all those drugs will appear again in the section on interactions.
Method of administration and dosage
Adults are usually given folic acid at a dose of 10–45 mg a day, and the dose that replenishes tissue reserves is 10–20 mg. The particular regimen is chosen according to the diagnosis, and the differences between them are large — from 5 mg in one indication to tens of milligrams in another.
| Situation | Dose |
| Adults, general range | 10–45 mg a day |
| Replenishing tissue reserves | 10–20 mg |
| Megaloblastic anaemia | 10–20 mg a day for 14–21 days, until haematological improvement, then a maintenance dose of up to 10 mg a day |
| Haemolytic anaemia | 5 mg a day or once a week — depending on the diet and the severity of haemolysis |
| Children and adolescents | usually 5–15 mg a day depending on the indication |
| Any daily dose above 15 mg | take in 2–3 divided doses |
The product information gives no figure for the duration of treatment: it is set according to the patient's response and the results of laboratory tests. Hence the requirement for periodic blood tests — they are not a formality here but the only way to tell whether the chosen dose is working. In megaloblastic anaemia this logic is visible directly in the regimen: the high dose is held for 14–21 days, until haematological improvement, and only then is the maintenance dose taken up.
Contraindications
The list of contraindications is short — there are only two. First: hypersensitivity to the active substance or to any of the excipients. Second: certain neoplastic diseases. The second point is easiest to read together with the section on the mechanism: folic acid is needed for the synthesis of purine and pyrimidine bases, that is, for building the DNA and RNA of a dividing cell — and it is precisely the blockade of that pathway on which treatment with folic acid antimetabolites such as methotrexate rests.
It is no less useful to know what is absent from that list. Pregnancy and breastfeeding are not contraindications: both are expressly permitted, as a separate section below sets out. But a short list of prohibitions does not make the medicine harmless. The main precaution in folic acid treatment is written not here at all, but in the special warnings — and it concerns vitamin B12.
Special warnings and precautions
The issue is megaloblastic anaemia, which arises both from a lack of folic acid and from a lack of vitamin B12, and the blood picture in the two is similar. Folic acid partly corrects the haematological manifestations that depend on B12 deficiency, but it may aggravate the neurological ones. That is why, before the medicine is given, a thorough work-up is carried out specifically for B12 deficiency, and in doubtful cases it is safer to give both vitamins at once. If megaloblastic anaemia associated with B12 deficiency is confirmed — including the Addison-Biermer type — folic acid is used with caution and B12 is given at the same time.
The second precaution concerns anticonvulsants. If folic acid is prescribed to a patient taking them, the blood concentration of those medicines must be monitored: there is a risk of epileptic seizures. The mechanism is explained in the section on interactions; what matters here is the practical consequence — starting the vitamin in such a patient calls for a test, not just a prescription. To this is added the general rule of periodic blood monitoring to assess the effectiveness of treatment. And one reassuring line: the medicine has no effect on the ability to drive or to operate machinery.
Interaction with other medicines
The first group of interactions weakens the medicine itself. Oral contraceptives, that is oestrogens, antituberculosis drugs, ethanol and the ion-exchange resins used in hyperlipidaemia can reduce the effectiveness of folic acid preparations — through increased metabolism or decreased absorption. Note a curious detail: oral contraceptives stand both among the indications and here. There is no contradiction — they both create an increased need for the vitamin and hinder its work, and so call for double attention.
The second group acts more subtly — it strikes at the conversion of the vitamin into its active form. Folic acid antagonists (sulfonamides, trimethoprim, pyrimethamine, sulfasalazine) and antineoplastic agents (methotrexate) competitively block dihydrofolate reductase and thereby disturb the conversion of folic acid into biologically active tetrahydrofolic acid; the effectiveness of the vitamin preparations then falls. The third group is the anticonvulsants: phenobarbital, phenytoin, primidone. Here it is the other way round, the influence runs from the vitamin to the drug: folic acid normalises, that is increases, the rate of their metabolism, previously lowered by the deficiency. The blood concentration of the anticonvulsants must therefore be monitored and their dose raised if necessary, so as not to provoke a seizure.
Pregnancy and breastfeeding
This section sounds not like a warning but like a permission. Properly conducted epidemiological studies show no harmful effect of folic acid on the course of pregnancy or on the health of the fetus and newborn, and the medicine may be used during pregnancy. More than that, the same studies show the opposite: taking folic acid preparations before conception and in the first weeks of pregnancy reduces the risk of neural tube defects in the fetus.
The mechanism of that prevention is described in the section on the mechanism of action: increasing the supply of folic acid — both in the diet and in the form of medicines — for at least a month before the expected conception and in the first trimester reflects the roughly twofold increase in the need for this vitamin and is a recognised element of neural tube defect prevention. Breastfeeding is likewise permitted: folic acid passes into human milk, but no negative effect on breastfed children has been established. The dose is set by the doctor — the daily doses in the product information are therapeutic, not those taken as an ordinary preventive supplement.
Adverse effects
The overall assessment in the product information is brief: folic acid rarely causes unwanted effects. Most often these are cutaneous allergic reactions, but very rarely it may come to severe allergic reactions in the form of angioedema or bronchospasm. The list is built on the standard scheme — first by frequency, then by system organ class according to MedDRA terminology, and within each group the symptoms run in order of increasing severity.
Uncommonly, on the part of the immune system, cutaneous allergic reactions are recorded: rash and itching. Rarely there are stomach and intestinal disorders — a bitter taste in the mouth, bloating, nausea, vomiting, diarrhoea. Rarely, psychiatric disorders have also been described: lack of appetite, difficulty falling asleep, drowsiness, excessive nervous excitability, depression. Very rarely, on the part of the immune system, angioedema and bronchospasm develop — the only conditions on the whole list that require immediate help. The remaining reactions are a reason to discuss the dose with the doctor, not a sign of danger.
Overdose
The clinical picture of acute overdose is unknown, and the reason is stated plainly: no cases of folic acid overdose have been described to date. If a patient has nonetheless taken a dose considerably higher than recommended, it is advisable to induce vomiting and observe them, and if necessary to start appropriate symptomatic treatment.
The absence of described cases does not mean the dose can be exceeded with impunity. The real risk in folic acid treatment lies not in a single excess but in what the special warnings caution against: a large dose of the vitamin can improve the blood picture in an unrecognised B12 deficiency and thereby conceal it while neurological damage goes on developing. That is exactly why the dose is chosen from test results and not from how one feels.
How to get a prescription for Acidum folicum Richter online
Before starting folic acid at a therapeutic dose you need to know whether you have a vitamin B12 deficiency: the vitamin will put the blood picture right but may worsen the neurological signs. Hence the prescription status of the 5 mg and 15 mg tablets — the doctor needs to see test results, not just complaints. On e-zdrowie.com you fill in a medical questionnaire, the doctor reviews the answers and, if the medicine is suitable, issues an electronic prescription: the code arrives by message, and any Polish pharmacy will dispense the tablets against it.
Begin the questionnaire with your test results: give your haemoglobin, mean corpuscular volume, folate and vitamin B12 levels if those tests have already been done, and the date of your last blood test. Then name the reason you need the vitamin: haemolytic anaemia, megaloblastic anaemia, dialysis, malnutrition, alcohol dependence. List your medicines separately — anticonvulsants, methotrexate, sulfasalazine, trimethoprim, pyrimethamine, sulfonamides, oral contraceptives, ciclosporin: some require blood concentration monitoring, others themselves reduce the effectiveness of the vitamin. Be sure to report neoplastic disease and any allergy to the components of the medicine — these are the only two contraindications. And say whether you are pregnant or planning a pregnancy: for that indication the doctor works out the dose and the starting point separately.
