Status Report--Retracing the history of the early development of national chronic disease surveillance in Canada and the major role of the Laboratory Centre for Disease Control (LCDC) from 1972 to 2000

Health surveillance is the ongoing, systematic use of routinely collected health data to guide public health action in a timely fashion. This paper describes the creation and growth of national surveillance systems in Canada and their impact on chronic disease and injury prevention. In 2008, the authors started a review process to retrace the history of the early development of national chronic disease surveillance in Canada from 1960 to 2000. A 1967 publication describes the history of the development of the Laboratory of Hygiene from 1921 to 1967. This review is a sequel to that paper and describes the history of the development of national chronic disease surveillance in Canada before and after the formation of the Laboratory Centre for Disease Control (LCDC).

Acute allergic interstitial pneumonitis induced by hydrochlorothiazide

OBJECTIVE

To examine the clinical features of 4 unpublished cases and 26 published cases of acute allergic interstitial pneumonitis induced by hydrochlorothiazide (HCT).

DATA SOURCES

The unpublished cases were found in the database of the Drug Adverse Reaction Program, Health Protection Branch, Department of National Health and Welfare, and the database of the Programme conjoint de pharmacovigilance, in Quebec. The published cases were retrieved from MEDLINE and EMBASE.

STUDY SELECTION

Reported cases were selected if they were sufficiently documented. All published cases were selected because a differential diagnosis had been made in each one.

DATA SYNTHESIS

The onset was acute and dramatic; the average time to onset of symptoms was 44 minutes. Sex was a predominant risk factor, since 27 (90%) of the 30 patients were women. The average age was 56 years; thus, most of the women were postmenopausal. Over two-thirds of the patients had one to three positive prechallenges or rechallenges, 3 of the 52 documented adverse events occurred after a voluntary rechallenge, some were life-threatening and necessitated mechanical ventilation, and 1 was fatal. Treatment was supportive; avoidance of HCT was the only prevention.

CONCLUSION

Acute allergic interstitial pneumonitis due to HCT is extremely rare and potentially fatal. Such a reaction can be diagnosed only if the clinician suspects it when presented with a case of unexplained acute pulmonary edema.

Quality criteria for early signals of possible adverse drug reactions

The main function of the World Health Organisation's International Collaborative Programme on Drug Monitoring is to provide a reliable early warning of possible health hazards caused by medicines. Described here is an attempt to devise criteria that would produce a well-founded early signal of an adverse reaction on the basis of reports sent in by national collaborating centres and combined in the WHO database. To reduce the frequency of spurious associations (false-positive signals) it is suggested that publication be delayed until a few case-histories meeting the suggested criteria have been sent in. The criteria were tested retrospectively against early published case-reports on drug-associated agranulocytosis. 19 suspected associations were examined and a signal in the database was defined by there being three or more cases containing stipulated information about the patient and the treatment. The WHO database had reports on all the associations, suggested criteria for a signal being met in 15 instances. This signal was present when the first case was published in 7 instances and within three months of first publication in 1. Moreover, in 3 instances where publication came first the cases presented had been collected by a national drug monitoring centre. The WHO databank has the potential to provide doctors and scientists with signals which then should be evaluated in detail.

Excipients and additives: hidden hazards in drug products and in product substitution

The excipients and additives in drug formulations have been described as inert because they do not have an active role in the prevention or treatment of particular ailments. This has led to the misconception among physicians, pharmacists, drug manufacturers and the public that excipients are harmless and unworthy of mention. In fact, pharmacists are allowed to substitute drug formulations, without regard to the excipients, as long as they ensure that the active ingredients in the substitute are the same as those in the formulation prescribed. The inappropriateness of the term inert is becoming increasingly apparent as evidence of adverse reactions--some fatal--to excipients mounts. The likelihood that some "active" constituents, particularly erythromycin, have been blamed for such reactions deserves to be investigated. The public deserves to be better protected. For example, the United States has legislation requiring complete labelling of all food, drugs and cosmetics that incorporate more than one ingredient, no matter how innocuous the constituents are believed to be. In Canada, drug manufacturers are not even required to share this information with physicians or pharmacists when they introduce a new drug or reformulate a product already being marketed, nor are pharmacists required to disclose the contents of formulations that they prepare in the absence of commercially available products.

The gap to fill-human toxicology

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The Canadian drug adverse reaction reporting program

The origins and objectives of the Food and Drug Directorate's Drug Adverse Reaction Reporting Program are reviewed. A brief report from (F&D 123), which has been made available to all physicians, provides the means whereby suspected reactions to drugs can be reported to the Directorate. Information contained in these reports is treated as confidential. Twelve Canadian teaching hospitals have entered into a contractual agreement with the Directorate in order to investigate and evaluate suspected drug reactions occurring in the hospital setting. Manufacturers are notified if a problem appears to be arising in connection with a product, and discussions are held before any regulatory action is taken. Also, under the New Drug Regulations of 1963, pharmaceutical manufacturers are required to notify the F.D.D. if any unexpected reactions occur in association with their products. The Food and Drug Directorate is giving considerable thought to the means by which the interest of the profession in this program may be stimulated.