Canadian Adverse Reaction Newsletter, Volume 23 - Issue 3 - July 2013

ISSN 1499-9447
Cat no H42-4/1-23-3E

Health Products and Food Branch
Marketed Health Products Directorate
Canadian Adverse Reaction Newsletter Editorial Team

In this Issue:

• Oral fluoroquinolones and retinal detachment
• Adverse reaction and incident reporting-2012
• Summary of advisories

Scope

This quarterly publication alerts health professionals to potential signals detected through the review of case reports submitted to Health Canada. It is a useful mechanism to stimulate adverse reaction reporting as well as to disseminate information on suspected adverse reactions to health products occurring in humans before comprehensive risk-benefit evaluations and regulatory decisions are undertaken. The continuous evaluation of health product safety profiles depends on the quality of your reports.

Reporting Adverse Reactions
Canada Vigilance Program
Phone: 1-866-234-2345
Fax: 1-866-678-6789

For more information on how to report an adverse reaction, visit the Reporting Adverse Reactions to Drugs and Other Health Products page.

Caveat: Adverse reactions (ARs) to health products are considered to be suspicions, as a definite causal association often cannot be determined. Spontaneous reports of ARs cannot be used to estimate the incidence of ARs because ARs remain underreported and patient exposure is unknown.

Oral fluoroquinolones and retinal detachment

Oral fluoroquinolones are broad-spectrum antibacterial drugs indicated for the treatment of infections caused by susceptible strains of microorganisms.^{Footnote 1,Footnote 2,Footnote 3,Footnote 4,Footnote 5} In Canada, there are 5 marketed oral fluoroquinolones: ciprofloxacin (first marketed in 1996), levofloxacin (1997), moxifloxacin (2000), norfloxacin (1986), and ofloxacin (1990). The risk of retinal detachment is not described in any of the oral fluoroquinolone Canadian product monographs.

Retinal detachment is characterized by a separation of the retina from the underlying tissue in the eye.^{Footnote 6} Among the different types of retinal detachment, rhegmatogenous retinal detachment (RRD) is the most common. RRD results from retinal breaks caused by vitreoretinal traction. Risk factors commonly associated with retinal detachment include advancing age, previous cataract surgery, myopia and trauma. Patients generally present with symptoms such as light flashes, floaters, peripheral visual field loss and blurred vision. Retinal detachment is a serious medical emergency that generally requires prompt surgical intervention.^{Footnote 6,Footnote 7}

According to a pharmacoepidemiological study, current use of oral fluoroquinolones was associated with an increased risk of developing retinal detachment.^{Footnote 7} Ophthalmic fluoroquinolones were excluded from the study to avoid reverse causality bias. The study identified 445 cases of retinal detachment involving oral fluoroquinolone use in a cohort of 989 591 patients from British Columbia who visited an ophthalmologist between January 2000 and December 2007. Further research is needed to confirm whether there is a potential association between retinal detachment and fluoroquinolones as well as to clarify the mechanism of action.

As of Dec. 31, 2012, Health Canada received one report of retinal detachment suspected of being associated with the use of an oral fluoroquinolone. The report described a 52-year-old woman who experienced retinal detachment after a course of ciprofloxacin prescribed to treat a bladder infection.  Limited evidence linking retinal detachment to oral fluoroquinolones may explain the low level of reporting to Health Canada.

Health care professionals are encouraged to report to Health Canada any adverse reactions (ARs) suspected of being associated with oral fluoroquinolones, and related to the development of retinal detachment. Information such as treatment duration, dosage, current or previous exposure to oral fluoroquinolones, as well as symptoms related to retinal detachment such as light flashes, floaters and peripheral visual field loss are important to include when reporting ARs. This information may help to further evaluate AR reports related to retinal detachment suspected of being associated with oral fluoroquinolone use.

Alain Beliveau, PhD, Health Canada

References

Adverse reaction and incident reporting-2012

Canada Vigilance Program

The Canada Vigilance Program collects reports of suspected adverse reactions (ARs) to health products (pharmaceuticals, biotechnology products, blood products and biologics, natural health products, radiopharmaceuticals, and cells, tissues and organs). Further information about the program and its database can be found on the MedEffect™ Canada Web site.

Domestic and foreign AR reports

In 2012, Health Canada received 53 109 domestic AR reports,^{Footnote 8} of which 79% were considered to be serious.^{Footnote 9} Domestic AR reports received by product type are provided in Table 1. The 53 109 reports represent 36 101 AR cases. A case consists of all information describing the AR(s) experienced by one patient at one time and suspected of being related to the use of one or more health products; thus, an AR case will include an initial AR report as well as any subsequent additional information received as follow-up report(s).

In Canada, Market Authorization Holders (MAHs) are required to submit AR reports received in accordance with the requirements of the Food and Drugs Act and Regulations. MAHs are required to send, within 15 days, all reports of serious ARs that have occurred in Canada (domestic) and all reports of serious unexpected ARs^{Footnote 10} that have occurred outside Canada (foreign) to the Canada Vigilance Program. In 2012, MAHs submitted 84.4% of all the domestic reports received. The remaining reports were received directly from the community and hospitals (Table 2).

The number of domestic AR reports was 26.7% higher in 2012 than in 2011 (Fig. 1). Most of the domestic reports received by both MAHs and Health Canada originated from health care professionals (Table 3).

In 2012, the number of foreign AR reports received from MAHs was 542 052 (Fig. 2). These reports are not included in the Canada Vigilance database.

Sex and age

The distribution for the 36 101 cases by sex was 58% female, 36% male and 6% sex unknown. The distribution by age group was 5% pediatric (< 19 years), 52% adult (19-64 years), 26% elderly (≥ 65 years) and 17% age unknown.

Suspect products

The top 10 groups of suspect products most commonly identified in AR reports are listed in Table 4. Anatomical Therapeutic Chemical (ATC) groups are classified according to the  World Health Organization's ATC classification system. Several factors may influence the number of ARs reported for a specific health product or product type, such as length of time a product is on the market, volume of use, publicity of an AR, regulatory actions, method of data collection (reports submitted voluntarily versus organized data-collection systems). For example, ARs may be reported more frequently in organized data-collection systems (e.g., patient registries, surveys, patient support and disease management programs) and may affect the pattern of reporting. It is not possible to compare the risk of health products based solely on numbers of AR reports. In addition, rare and serious reactions may not necessarily represent a large number of reported ARs.

Adverse reactions

Table 5 displays the top 10 ARs reported to the Canada Vigilance Program, based on System Organ Class.^{Footnote 11} The most commonly reported ARs were general disorders and administration site conditions, which include disorders that affect several body systems or sites (e.g., drug ineffective, fatigue, fever, edema, pain, reactions at the administration site). The next most common ARs were gastrointestinal disorders.

Conclusion

Health Canada would like to thank all who have contributed to the Canada Vigilance Program and encourages the continued support of postmarketing surveillance through AR reporting. The purpose of postmarket spontaneous reporting systems is the identification and analysis of new safety information for health products. Any ARs suspected of being associated with the use of health products can be reported to the Canada Vigilance Program.

Medical device incidents

Medical device incident reports are collected by Health Canada and are entered into the Medical Devices System database. A major component of Health Canada's Medical Devices Program involves the collection, review and follow-up of incidents related to medical devices, which are reported to Health Canada via the submission of mandatory and voluntary problem reports. Manufacturers and importers are required to submit mandatory reports as per sections 59 to 61 of the Medical Devices Regulations. Voluntary reports are submitted mostly by health care professionals and patients/users.

In 2012, a total of 8 976 reports were entered into the Medical Device System database. Of these reports, 8 259 (92%) were domestic mandatory reports, 313 (3.5%) were foreign mandatory reports, and 404 (4.5%) were domestic voluntary reports.

A small reduction (2%) in the total number of reports received was noted for 2012, relative to the previous year. This change is primarily due to a decrease in foreign mandatory reports received by Health Canada. The number of domestic mandatory reports was slightly higher (1%) in 2012 compared with 2011. The majority of these mandatory reports were for incidents involving class II (29%) and class III (46%) medical devices (class IV being the highest-risk devices). The device categories representing the highest proportion of mandatory reports continue to be general hospital (29%) and cardiovascular (21%) devices.

The collection and maintenance of mandatory problem reports for medical devices is the responsibility of the Canada Vigilance-Medical Device Problem Reporting Program. For information on the submission of mandatory and voluntary reports for medical device incidents, please visit the Health Canada Web site.

Marielle McMorran, BSc, BSc(Pharm); Jennifer McEnaney, BSc, MBA, Health Canada

Quarterly Summary of health professional and consumer advisories

To receive the Newsletter and health product advisories free by e-mail, subscribe to MedEffect e-Notice.

Canadian Adverse Reaction Newsletter

Health Canada
Marketed Health Products Directorate
Address Locator 0701D
Ottawa ON K1A 0K9
Telephone: 613-954-6522
Fax: 613-952-7738

Editorial Team
Patricia Carruthers-Czyzewski, BScPhm, MSc (Editor-in-Chief)
Jared Cousins, BSP
Hoa Ly, BSc
Emir Al-Khalili, RPh, BScPhm, MSc
Aleksandar Brezar, BSc
Hélène Perrier, RPh, BSc(Pharm)
Sophie Bourbonnais, BScPht
Nicoleta Hosszu Ungureanu, MSc

Acknowledgement
We thank the following members of the Expert Advisory Committee on the Vigilance of Health Products for their review of material for this issue: Colleen J. Metge, BSc(Pharm), PhD; Yola Moride, PhD, FISPE; Rishma Walji, ND, PhD; and Darrel Forsythe, RN, BN, ACCN. We also thank Kristina Klinovski, BSc, and Rachel Mailhot, students in Occupational Therapy and Biomedical Sciences, respectively, for their participation in the production of the newsletter.

Suggestions?
Your comments are important to us. Let us know what you think.

Reporting Adverse Reactions
Canada Vigilance Program
Telephone: 1-866-234-2345
Fax: 1-866-678-6789

Copyright
© 2013 Her Majesty the Queen in Right of Canada. This publication may be reproduced without permission provided the source is fully acknowledged. The use of this publication for advertising purposes is prohibited. Health Canada does not assume liability for the accuracy or authenticity of the information submitted in case reports.

Due to time constraints relating to the production of this publication, information published may not reflect the most current information.