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Folate, absorption epilepsy

Folate deficiency is most likely to occur in patients on long-lasting AED therapy. Furthermore, folate concentrations are inversely related to the number of prescribed AEDs. Patients on combinations of two or more AEDs tend to have lower folate levels than patients on monotherapy. Combinations of AEDs may have synergistic effects on folate absorption and/or metabolism. Moreover, the dietary intake of B vitamins tends to decrease with an increasing number of AEDs. Patients on combination therapy tend to a have more severe epilepsy, often associated with other neurological deficits and may even need to live in institutions. [Pg.543]

Oxidized folate is not only metabolically dead buyt may even be neurotoxic. For example, a patient with epilepsy who has not had a convulsion in years because dilantin has produced complete control, can be thrown into an immediate convulsion with a megadose of folic acid, because folic acid and dilantin compete for absorption at the brain cell surface, and too much oxidized folic acid will block the ability of the brain cell to take up dilantin, similar to the competition between dilantin and folic acid for uptake by the gutcell (22). [Pg.41]

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]


See also in sourсe #XX -- [ Pg.312 , Pg.319 ]

See also in sourсe #XX -- [ Pg.312 , Pg.319 ]

See also in sourсe #XX -- [ Pg.312 , Pg.319 ]




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Epilepsy, folate

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