Reversible absorptive defects in anticonvulsant megaloblastic anaemia

Abstract

Two cases of anticonvulsant megaloblastic anaemia are described, showing features of unusual interest. Though both cases were apparently deficient in folic acid, the Figlu tests were negative. One patient had an extremely low serum B12concentration apparently associated with defective B12absorption due to deficiency of intrinsic factor, and both showed impaired intestinal absorption of D-xylose. There was, however, no evidence of permanent gastro-intestinal dysfunction, and the absorptive defects disappeared completely after treatment with folic acid.Possible reasons for the findings are discussed. It is suggested that absorptive defects produced by the drugs may play some part in initiating anticonvulsant megaloblastic anaemia, and that once deficiencies of haemopoietic factors are established, a vicious circle may be set up owing to the effects of these deficiencies on the gastro-intestinal tract.

Temperate sprue

“…The dietary history of our patient did not suggest that his folate intake was low. Folic acid deficiency with impaired xylose absorption but without steatorrhoea or other evidence of proximal small bowel dysfunction has been described in an alcoholic female (Forshaw, 1969) and in two patients with malabsorption associated with anticonvulsant therapy (Reynolds et al, 1965). Our patient seems to have been abstemious and there was no history of drug therapy of any kind immediately preceding or during his illness.…”

“…Malabsorption is usually present and though nutritional deficiency may appear slight, there is invariably evidence of folic acid deficiency at this stage (O'Brien & England, 1964). At the onset of the disease jejunal biopsies may show remarkably little change (Shechy, Cohen & Brodsky, 1963). There is usually defective proximal bowel function with failure of absorption of glucose, xylose and folic acid.…”

Acute diphenylhydantoin and primidone poisoning treated by peritoneal dialysis.

“…On the basis of the findings of Reynolds et al (1966) and Reynolds, Hallpike, Phillips, and Matthews (1965) concerning the effect of diphenylhydantoin together with certain other anticonvulsants in producing folate and vitamin B12 deficiency associated with reversible impairment in intestinal absorption large doses of folate and vitamin B12 were administered parenterally during and after dialysis. D-xylose and Schilling tests carried out subsequently were normal.…”

Absorption of protein digestion products: a review.

“…The members of the B6 group are the only vitamins which have definitely been shown to affect amino-acid absorption, though Erf and Rhoads (1940) noted that the glycine tolerance curve was depressed in pernicious anaemia but not in other severe anaemias. Any effect of B12 deficiency may well be nonspecific (Reynolds, Hallpike, Phillips and Matthews, 1965). The absorption of xylose may also be defective in pernicious anaemia (e.g., Butterworth, Perez-Santiago, de Jesus, and Santini, 1959).…”