acid is that they are less effective in reducing triglyceride and raising HDL levels.2 There is also concern that they are more hepatotoxic.3 We have recent evidence from our laboratory4 that may explain the differences between the slow-release formulation and the regular one. Nicotinic acid is metabolized along two pathways: it is converted to nicotinamide adenine dinucleotide (NAD) or, through the formation of nicotinyl coenzyme A followed by conjugation with glycine, to nicotinuric acid. We suspect that the formation of NAD is a saturable process and that significant formation of nicotinuric acid occurs only when niacin is administered in the regular formulation. We suspect also that the form that is beneficial to lipid levels is nicotinyl coenzyme A. Our findings suggest that to achieve the benefits of niacin therapy and avoid hepatotoxicity niacin should be used in its regular formulation and that, regrettably, although use of the slowrelease formulation minimizes the flushing it will both reduce the efficacy and increase the toxicity of this effective and underutilized treatment. Our experience is similar to that of Henkin and associates,3 who found that with appropriate warning and encouragement to patients niacin was well tolerated in 83% of cases. J. David Spence, MD, FRCPC Division of Clinical Pharmacology University of Western Ontario Hypertension Research Unit Victoria Hospital London, Ont.

References 1. Stern RH, Spence JD, Freeman J: Tolerance to nicotinic acid flushing. Clin Pharmacol Ther 1991; 50: 66-70 2. Knopp RH, Ginsberg J, Albers JJ et al: Contrasting effects of unmodified and time-release forms of niacin on lipoproteins in hyperlipidemic subjects: clues to mechanism of action of niacin. Metabolism 1985; 34: 642-650 3. Henkin Y, Oberman A, Hurst DC et al: 438

CAN MED ASSOC J 1992; 146 (4)

Niacin revisited: clinical observations on an important but underutilized drug. Am JMed 1991; 91: 239-246 4. Stern RH, Freeman J, Spence JD: Differences in metabolism of time-release and unmodified nicotinic acid: explanation of the differences in hypolipidemic action? Metabolism (in press)

[The author responds.: The use of niacin involves several issues that should be addressed separately. First and foremost is that of hepatotoxicity. Hepatotoxicity has been thought to be more prevalent with slow-release niacin than with the regular type of niacin. A review of the literature, however, reveals sporadic case reports on niacin hepatotoxicity and a highly publicized case of liver failure after administration of niacin in modest to high doses. In our clinical experience hepatotoxicity (a threefold elevation of aspartate or alanine aminotransferase levels) is an infrequent problem at doses of a slow-release form of niacin (Bronson Pharmaceuticals, La Canada, Calif.) of up to 3 g daily. This slow-release formulation was as well tolerated as Nicobid (Rhone-Poulenc Rorer) in a pilot crossover study (unpublished data). Our clinical (and admittedly anecdotal) experience with niacin is that the usual overthe-counter niacin is not well tolerated by our patients. We now have experience with the slowrelease form and find it leads to better compliance. For clinicians the side effects of niacin have been a far greater impediment to appropriate therapy than the hepatotoxicity. Our current recommendation for patients with combined hyperlipoproteinemia that does not respond to dietary therapy is to start niacin at doses of up to 3 g daily and to carry out liver function tests every 6 weeks and then every 3 months. The data recently published by Keenan and colleagues' closely parallel our clinical experience. However, we do not

have data showing that the degree of cholesterol reduction is greater, the same or less with the slowrelease form of niacin than with regular niacin. I find it difficult to interpret pharmacokinetic data on the slowrelease form of niacin, since there were at least 20 to 25 different forms of it available in 1991. Therefore the bioavailability of each agent has not been fully examined. It is very likely that using low doses of fibric acid derivatives in combination with bile-acid binding resins or, in severe cases, low doses of hepatic hydroxymethylglutaryl-coenzyme A reductase inhibitors will become useful in the treatment of combined hyperlipoproteinemia in which the levels of triglycerides and low-density lipoproteins are increased and the levels of HDL are decreased. However, this combination therapy should be used in experienced hands and with scrupulous moni-

toring for side effects. Jacques Genest, Jr., MD, FRCPC Cardiovascular Genetics Laboratory Clinical Research Institute of Montreal Montreal, Que.

Reference 1. Keenan GM, Fontaine PL, Wenz JB et al: Niacin revisited: a randomized, controlled trial of wax-matrix sustainedrelease niacin and hypercholesterolemia. Arch Intern Med 1991; 151:


Occupational therapy in the community W M , ' s. Margaret Brockett's editorial (Can Med Assoc J 1991; 145: 929930) outlines some of the new initiatives of occupational therapists. Their work is very valuable in restoring patients to their optimum level of functioning. However, in responding to LE 15 FEVRIER 1992

the challenge of an aging population occupational therapists must realize the expense of their services. Helping older patients to cope with such problems as mounting stairs or turning on the videocassette recorder is the work not of a highly qualified professional but of other personnel, possibly working under the direction of the occupational therapist (or other health care professional). Such a devolution of duties would amount to a great saving in the delivery of health care and give reasonable employment to many semitrained people. I am concerned about the fact that occupational therapists work with "clients" but physicians work with "patients." The semantics create an artificial barrier that smudges communication and promotes individual enterprise rather than a team approach. Charles M. Godfrey, MD 107-484 Church St. Toronto, Ont.

[The author responds.] The demand for occupational therapists far exceeds the supply, and projections suggest that this situation is unlikely to change in the immediate future. Dr. Godfrey is correct in pointing out that much of the practice of the activities prescribed by occupational therapists for their clients can be and is undertaken by support personnel, family members and volunteers. These people need to be schooled by the supervising occupational therapist in the specific components of the prescribed activity, the appropriate ways of accomplishing it and the aspects to be observed and, when necessary, modified by the client and helper or referred back for further consultation. The Canadian Association of Occupational Therapists is working with other rehabilitation 440

CAN MED ASSOC J 1992; 146 (4)

professions and with the Department of National Health and Welfare to determine how support personnel can best be trained and utilized, particularly in the community, where supervision can only be at a distance. Margaret Brockett, BSR(OT), OT(C) 45 Belgravia Ave. Toronto, Ont.

Covert influence? Ithough I am always a ppleased to receive my copy of CMAJ I was surprised to find enclosed with the Nov. 15, 1991, issue the pamphlet "Innovations: an Update on Diet, Cholesterol, Health and Eggs," supplied by the provincial egg marketing boards. My concern is the use of CMAJ as a vehicle for disseminating literature supplied by special interest groups. This pamphlet details important information on consuming a healthy diet but also includes a tacit reminder to physicians not to advise patients to avoid eggs, because "within such a [well-balanced] diet, eggs have an appropriate place." It is my impression that recent CMA guidelines were aimed at preventing this covert influence on doctors. Indeed, I support the recommendations in the brochure on maximizing heart health. However, I would prefer them to have come from CMAJ itself. Surely the Canadian Egg Marketing Agency is as interested in promoting its product as it is in the health of our patients.

cern about distributing literature supplied by special interest groups, but because a group has a special interest in a product does not mean that the information it supplies is wrong or inappropriate. Just as pharmaceutical firms have played a major role in supplying useful information to physicians, we believe that agencies such as the egg marketing boards have been able to help physicians provide useful information about diet and heart health while correcting some misapprehension about the harmful effects of eggs. Bruce P. Squires, MD, PhD Editor-in-chief

A survey of resuscitation training in Canadian undergraduate medical programs I n Table 1 of the article by Drs. David H. Goldstein and Robert K. Beckwith (Can Med Assoc J 1991; 145: 23-27) McMaster University is shown to require no undergraduate training in resuscitation. This is an unfortunate misrepresentation. Our core undergraduate program includes a course for first-year students on the "ABCs of emergency medicine." This is a basic first-aid module that combines 8 hours of instruction and demonstration with 4 hours of practical experience with simulated patients. The module includes management of the airway, the circulation and shock, altered levels of consciousness and coma, spinal injury and

fractures. McMaster University's core Gordon S. Bierbrier, MD, CM program includes the option of 607-575 Proudfoot Lane long-term ("horizontal") or shortLondon, Ont. term ("block") electives in emer[CMAJ responds:] gency medicine. Students usually start the "horizontal" electives in We appreciate Dr. Bierbrier's con- their first or second year. The LE 15 FEVRIER 1992

Occupational therapy in the community.

acid is that they are less effective in reducing triglyceride and raising HDL levels.2 There is also concern that they are more hepatotoxic.3 We have...
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