Letters to the Editor

(Aust Prescr 1994;17:4-5)

Letters, which may not necessarily be published in full, should be restricted to not more than 250 words. When relevant, comment on the letter is sought from the author. Due to production schedules, it is normally not possible to publish letters received in response to material appearing in a particular issue earlier than the second or third subsequent issue.

Prostate specific antigen

Editor, - I was interested in the article 'Prostate specific antigen', by Dr J.V. Wells (Aust Prescr 1993;16:37-9), but very disappointed to find no hint of the costs of the various tests.

I know that it is impossible to give exact costings, but some very general indication and comparison with other tests (e.g. the various acid phosphatases) seems essential to me for the rational selection of tests in the conditions of today.

G.J. Fraenkel
Emeritus Professor and Former Dean
Flinders University
Torrens Park, S.A.

Dr J. V. Wells, the author of the article, comments:
The current approach to early detection of prostate cancer involves digital rectal examination, serum PSA and trans-rectal ultrasound (TRUS), with or without biopsy. The use of phosphatases has almost disappeared in the major centres. There is therefore only one laboratory test - PSA. The only cost comparison would be to compare costs of different kits.

Cancer, the menopause and hormone replacement therapy

Editor, - A recent article by Professor S.K. Khoo (Aust Prescr 1993;16:66-8) discussed the safety of hormone replacement therapy (HRT) in postmenopausal women. Despite the plethora of information being published in the medical arena in support of this therapy, there remain real controversies about some aspects of its safety, especially with respect to breast cancer.

In women without prior cancer, a meta-analysis of 16 published studies demonstrated a relatively small (30%) but statistically significant increase in breast cancer risk.1 Of even greater importance is the finding that in women with a family history of breast cancer using some form of HRT, this risk increased 3-fold (confidence limits 2-6) compared to those who had never used oestrogen replacement therapy. This issue was not adequately addressed by the author. It is important for women to be able to make an informed decision. However, such informed decision making is not possible unless the evidence presented to the medical profession is clear and unbiased.

Whilst HRT is clearly beneficial for the control of menopausal symptoms, the use of such therapy in women at a higher risk of developing breast cancer should be at least clearly presented and we believe, strongly discouraged until further data provide evidence for the safety of such therapy.

Dr John Zalcberg
Director, Medical Oncology
and
Mr Jim Siderov
Senior Oncology Pharmacist
Department of Medical Oncology
Heidelberg Repatriation Hospital
Heidelberg West, Vic.

R E F E R E N C E

1. Steinberg KK, Thacker SB, Smith SJ, Stroup DF ,Zack MM, Flanders WD, et al. A meta-analysis of the effect of estrogen replacement therapy on the risk of breast cancer [published erratum appears in JAMA 1991;266:1362] [see comments]. JAMA 1991;265:1985-90. Comment in: JAMA 199 l;266:1358-60.

Professor S.K. Khoo, the author of the article, comments:
I agree that there is still continuing concern about the risk of breast cancer in postmenopausal women using HRT.

The epidemiological data reviewed in the section on 'Risk of breast cancer' is brief because of space restrictions; a fuller review is given elsewhere.1 Overall, the message from these data is reassuring in my view. In fact, if we accept that a large prospective study has a higher power of analysis, the Nurses Health Study2 involving 120 000 women for 360 000 person-years of follow-up is revealing. It found that only current users who reported alcohol consumption had a significantly increased relative risk of breast cancer, 1.56 (95% confidence interval 1.2 to 2.0); the risk in those users who reported no alcohol consumption was not increased, 0.99 (0.62 to 1.60). Undoubtedly, further studies are required to resolve the concern, but on the basis of present data, the established benefits of HRT would outweigh the risks especially in reducing cardiovascular and cerebrovascular deaths.

R E F E R E N C E S

1. Khoo SK, Chick P. Sex steroid hormones and breast cancer: is there a link with oral contraceptives and hormone replacement therapy? Med J Aust 1992; 156:124-32.

2. Colditz GA, Stampfer MJ, Willett WC, Hennekens CH, Rosner B, Speizer FE. Prospective study of estrogen replacement therapy and risk of breast cancer in postmenopausal women [published erratum appears in JAMA 1991;265:1828] [see comments]. JAMA 1990;264:2648-53. Comment in: JAMA 1991;265:1824-5.

Oral rehydration therapy

Editor, - I refer to the article 'Oral rehydration therapy for acute gastroenteritis in children' by Dr E. O'Loughlin (Aust Prescr 1993;16:61-3).

Articles from paediatricians which appear in journals and similar articles written by paediatricians for popular magazines concerning the management of vomiting illnesses give advice based on the condition of children as usually first seen by the specialists or the hospital staff.

The fact that a specialist and/or a hospital are involved indicates the illness has progressed along the road to dehydration and needs significant intervention.

Because advice in magazines warns mothers of the lethal potential of dehydration, they take the hydration advice very seriously indeed. So every time the child vomits, they feed 30 mL or so of ORS which the irritated stomach - not realising the good intention - promptly returns, usually with interest. And rather than reduce fluid loss, the mother usually succeeds in increasing it.

This is the common general practice experience. After a lengthy uphill battle, I eventually convinced 'my mothers' to initially starve the vomiting baby or child. 'Nothing by mouth for 3 hours and then try a little water - if rejected wait another 3 hours and try again, but ring me at any stage if you are getting anxious.' Invariably, those who phoned in earlier would admit that the vomiting returned after 'giving in' because the child asked for something or was licking their lips.

It is difficult to know how successful one is in a general practice, but admissions were uncommon and only moderately sick.

I believe the initial advice in this illness should be to fast as the gastric irritability settles during the first day in most cases.

N.J. Rogers
General Practitioner
Ballina, N.S.W.

Dr E. O'Loughlin, the author of the article, comments:
Dr Rogers raises a number of issues regarding the treatment of acute gastroenteritis which require comment. The suggestion that children with acute vomiting and diarrhoea should be fasted for some hours and then given a little water, because of gastric irritation, is without clinical or scientific foundation. The focus of treatment is the correction or prevention of dehydration as this is the major contributing factor to morbidity and mortality. Restricting fluid intake in a child with vomiting and diarrhoea is potentially dangerous and may add to the dehydration. Water absorption is very inefficient unless accompanied by an appropriate mixture of glucose and electrolytes as provided in oral rehydration solutions. Dr Rogers' contention that 'the irritated stomach - not realising the good intention - promptly returns, usually with interest' is incorrect in the majority of cases of children treated with oral rehydration solution. Despite ongoing symptoms, enough fluid usually reaches the small intestine to correct dehydration.

Dr Rogers also comments that when hospital specialists become involved, the illness has progressed to the more severe end of the spectrum. In my view, the use of appropriately constituted oral rehydration solutions early in the course of illness may prevent acute gastroenteritis progressing to the stage requiring admission to hospital or the need for specialists to be involved at all. Several thousand children are admitted to hospitals around Australia every year with acute gastroenteritis. Family doctors could be making a major impact on this problem by intervening early with oral rehydration solutions to prevent dehydration.

Advertising

Editor, - Your editorial 'Are medical journals selling out' (Aust Prescr 1993; 16:50-1) raised a real issue, even if it only applies to half a dozen medical journals in the country. At the Australian and New Zealand Journal of Medicine, all advertising is cleared through the Editor and the Clinical Pharmacology Sub-Editor and I estimate that about one advertisement in 5 requires some amendment.

The difficulties relate to the logistics of advertising. The advertising agent books the space in the journal many months ahead, but the copy is first presented as the final bromide for printing about two weeks before the issue goes to press. It is then difficult but not impossible to have advertising material changed. As far as I can tell, the journal's policy has not deterred advertising, although I imagine it would be hard to find out if it did.

Critical analysis of published data, either in editorial or advertising space, is not taught in many medical schools.

Perhaps Australian Prescriber could commission a critical analyst to write a feature or even have an 'ad. a month' section which, even within the libel laws, might provide an adequate base for demonstrating the relevant skills.

Graham Macdonald
Editor
Australian and New Zealand Journal of Medicine
Sydney, N.S.W.

Anti hypertensive therapy

Editor, - Patients medicated with nifedipine often present to the periodontist with gingival overgrowth. Several other drugs such as phenytoin and cyclosporin also have the propensity for gingival hyperplasia necessitating surgical intervention. This tissue overgrowth usually occurs in patients with pre-existing gingival inflammation, usually gingivitis or periodontitis and can cause enlargement which will interfere with function. With the increase in use of nifedipine amongst hypertensive individuals, the incidence of nifedipine hyperplasia is steadily rising. Treatment aimed at reducing gingival inflammation is essential before embarking on this therapy. In cases of overt reaction to nifedipine, the discontinuance of this medication is occasionally warranted.

I would be pleased if this could be brought to the attention of your readers.

S.B. Gairns
Periodontist
West Leederville, W.A.

Editorial note: Adverse reaction data suggest that this clinical problem may be a class effect of the dihydropyridine calcium antagonists.