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Primidone Folic acid

Special mention must be accorded to iatrogenic effects, where the usefulness of novel synthetic drugs is impaired by untoward side effects of obscure etiology. In some, if not many of them, these side effects may find their explanation in the inhibitory action of the drug upon a vitamin, as in the case of primidone vs. folic acid (B3a). These relationships appear to be fortuitous until the structural chemical kinship of drug and vitamin is recognized. [Pg.238]

B3a. Baker, H., Frank, O., Hutner, S. H., Aaronson, S, Ziffer, H., and Sobotka, H., Lesions in folic acid metabolism induced by Primidone. Experientia 18, 224-226... [Pg.239]

Drugs. Antiepilepsy drugs, particularly phenytoin, primidone and phenobarbital, occasionally cause a macrocytic anaemia that responds to folic acid. This may be due to enzyme induction by the antiepileptics increasing the need for folic acid to perform hydroxylation reactions (see Epilepsy) but other factors such as reduced absorption may be involved. Administration of folic acid causes a recurrence of seizures in some patients. Some anti-malarials, e.g. pyrimethamine, may interfere with conversion of folates to the active tetrahydrofolic acid, causing macrocytic anaemia. Methotrexate, another folate antagonist, may cause a megaloblastic anaemia especially when used long-term for leukaemia, rheumatoid arthritis or psoriasis. [Pg.597]

Most interactions of trimethoprim and co-trimoxazole with other drugs are due to fohc acid antagonism. This may be more pronounced with co-trimoxazole than with either drug alone. Such interactions have previously been suspected with anticonvulsants, such as barbiturates, phe-nytoin, and primidone, which themselves produce folic acid deficiency and megaloblastic anemia (88). In order to circumvent the risk of folate deficiency, folic acid or folinic acid can be given. There is some concern that folate replacement may antagonize the desired antimicrobial effect, particularly in some protozoal parasites, but this concern has been debated (89). [Pg.3517]

As with phenobarbital, serious toxicity for primidone is rare, although it may cause disabling sedation. Irritability, and decreased mental functioning In a number of persons. Ataxia, dysphoria, idiosyncratic rash, leukopenia, agranulocytosis, lymphadenopathy, hepatitis, and a systemic lupus erythematosus-like syndrome have been reported adverse effects for primidone. Deficiencies of folic acid and of vitamins D and K are possible with long-term therapy of primidone, as Is a folate-responsive megaloblastic anemia. Measurement of the complete blood cell count should be performed at 6-month intervals (40). [Pg.780]

Another long-term study was conducted in 26 patients with folic acid deficiency (serum folate less than 5 nanograms/mL), and treated with two or more drugs (phenytoin, phenobarbital, primidone). The mental state of 22 of them (as shown by increased alertness, concentration, sociability etc.) improved to a variable degree when they were given folic acid 5 mg three times daily. However, the frequency and severity of seizures in 13 patients (50%) increased to such an extent that the vitamin had to be withdrawn from 9 of them. ... [Pg.521]

A very well documented and clinically important interaction, which has been the subject of review." Reductions in serum phenytoin levels of 16 to 50% have been described in patients taking 5 to 15 mg folic acid daily for 2 to 4 weeks. If folic acid supplements are given to folate-deficient epileptics taking phenytoin, phenobarbital, primidone and possibly pheneturide, their serum antiepileptic levels should be well monitored so that suitable dosage increases can be made. [Pg.521]


See other pages where Primidone Folic acid is mentioned: [Pg.138]    [Pg.203]    [Pg.203]    [Pg.312]    [Pg.312]    [Pg.312]    [Pg.302]    [Pg.203]    [Pg.521]    [Pg.985]    [Pg.131]   
See also in sourсe #XX -- [ Pg.521 ]




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