1166 One aspect of dialysis which does not appear to have been considered is the capacity of the patient to dialyse himself. We have found that placing the dialyser behind the patient’s bed is totally impracticable for self-dialysis, which we have found extremely valuable in establishing the confidence of the patient in the dialysis system and reducing staffing requirements and cost.
In our experience, weight-loss during dialysis is not a linear function of time, as is suggested in fig. 3 of the article by Dr. Evans and his co-workers, but rather an exponential function. This points to the need for a bed weigher, since the patient’s blood-flow often falls towards the end of dialysis, especially on the passive-flow system; unless weight-loss is estimated by weighing during the dialysis, it is impossible to be sure that it is happening. R. BAILLOD C. COMTY J. HOPEWELL Renal Unit, M. ILAHI Royal Free Hospital, Lawn Road, S. SHALDON. N.W.3. London, EFFECTS OF YEAST EXTRACT AFTER MONOAMINE-OXIDASE INHIBITION SIR,-On the basis of animal experiments we suggested1
that foods (such as yeast products) which contain histamine might initiate or aggravate allergic conditions in patients treated with monoamine-oxidase inhibitors, and that headaches could be provoked in susceptible subjects. In two months
found that 156 this hospital,
outpatients, representing taking monoamineoxidase inhibitors. A questionary to 50 of these patients on their next visit elicited that a third (16) had a disorder which could be aggravated by histamine-including asthma (2), hayfever (4), food allergies (5), peptic ulcers (2), and other allergic disorders (4). 3 of these patients reported improvement in their condition during treatment; none of them was worse, including 3 allergic patients who continued to eat the yeast extract ’Marmite ’. Amine-oxidase inhibitors have been specifically recommended for the treatment of depression accompanying allergic conditions 2and peptic ulcers.4 In this series 27 patients were subject to severe headaches, and over half (16) had them weekly or more often. The incidence of such headaches was the same in the allergic group (8 out of 16) as in all the patients (27 out of 50). 3 patients recorded improvement in headaches during treatment, and only 1 (not an allergic patient) was worse. Many patients observed warnings to avoid foods containing amines and known to provoke hypertension, but almost half of them still continued to eat these. Of the 24 patients exposed to risk in this way, 18 had eaten broad beans, 15 had eaten cheese, 9 had eaten marmite, and 8 had had ’Bovril’ during the previous month. 3 patients reported feeling ill after food (1 after cream, 1 after broad beans, and 1 after cheese) but the incidence of severe headaches in patients eating cheese or marmite was almost the same (10 out of 17) as among those who avoided these foods (17 out of 33). This small series provides no evidence to support the suggestion that allergic manifestations are precipitated or we
2.5% of attendances
at
were
aggravated by absorption or potentiation of histamine from foodstuffs in patients treated with monoamineoxidase inhibitors. It confirms that severe frequent headaches are common in psychiatric patients. This symptom was largely uninfluenced by treatment, but an occasional severe headache associated with hypertension might pass unremarked, unless the specific features of this syndrome are elicited by direct questioning. Less than 1. 2. 3. 4.
Blackwell, B., Marley, E., Mabbitt, L. A. Lancet, May 1, 1965, p. 940. Sanger, M. D. Psychosomatics, 1964, 5, 164. Sanger, M. D. Ann. Allergy, 1962, 20, 705. Monat, H. A. Am. J. Gastroent., N.Y. 1962, 38, 188.
half (21) knew the name of the drug they were having, and 7 patients had taken cough medicines (possibly containing ephedrine) during the previous month, but none had suffered adverse effects. B. BLACKWELL Institute of Psychiatry, E. MARLEY Maudsley Hospital, D. TAYLOR. London, S.E.5. DANGERS OF NATURAL FOODSTUFFS SIR, To the foods listed in your editorial (May 1) as contraindicated for patients receiving monoamine-oxidase inhibitors, another may have to be added. Our experience
with a patient receiving pargyline (’ Eutonyl’) suggests that chocolate may be a potential offender. A 41-year-old woman (whose case is being reported more fully elsewhere 1) received 25 mg. pargyline daily for a fortnight, then 50 mg. daily for another 2 weeks, on account of mild hypertension. Towards the end of this period she had a severe hypertensive reaction after eating 100 g. of Rhodesian cheddar cheese. This was repeated 2 days later after a smaller quantity of cheese. She was then seen by one of us; the pargyline was stopped, and the patient was told not to take cheese, yeast extract, or broad beans for another fortnight. The next day, however, one hour after eating 60 g. of milk chocolate,
she had another similar attack. No other foods had been that were likely to have caused this reaction.
eaten
Cacao beans undergo fermentation for up to 12 days before drying and shipment. Several varieties of microorganisms are present in the fermenting pulp. By analogy with known reactions during the ripening of certain cheeses,3amines with pressor activity might arise during this process. Furthermore, chocolate contains vanillin,44 a catechol metabolite structurally similar to intermediates in the catabolism of noradrenaline and adrenaline. It would be interesting to know whether others have encountered pressor reactions in which chocolate was suspected as a factor, and, if so, whether the mechanism has been defined. Central Hospital,
D. M. KRIKLER.
Salisbury.
Department of Physiology, University College of Rhodesia and Nyasaland,
B. LEWIS.
Salisbury, Southern Rhodesia.
PROLONGED HYDROCORTISONE ADMINISTRATION AND POTASSIUM METABOLISM
SiR,ňThe conclusions reached by Dr. Bagshawe and his co-workers (Jan. 2) on the mechanism of hydrocortisone-induced hypokalsemia are not supported by their data. Their patients 5 and 7 illustrate the point. During the eleven control days, patient 5 had a positive balance of 144 mEq. potassium. During the first eleven days of hydrocortisone therapy (200 mg. per day), the patient, under essentially identical conditions (except for the administration of the drug), had a negative balance of 21 mEq. of potassium. The net difference between the two periods is 165 mEq. of potassium not retained during cortisol administration. Patient 7 during the eight control days had a positive potassium balance of 138 mEq. and during the first eight days of hydrocortisone administration (400 mg. per day) had only a net positive balance of 76 mEq. The total difference between the two periods is 52 mEq. of potassium not retained during cortisol administration.
Another of their data suggests 1. 2. 3. 4.
a
renal mechanism for the
Krikler, D. M. Cent. Afr. J. Med. (in the press). Roelofsen, P. A. Adv. Fd Res. 1955, 8, 225. Blackwell, B., Mabbitt, L. A. Lancet, May 1, 1965, p. 938. Winton, A. L., Winton, K. B. The Structure and Composition of Foods, vol. IV, p. 114. New York, 1939.