Mersey ADR Newsletter

Issue 22 Autumn 2003

A bulletin for prescribers discussing adverse drug reactions reported to the Mersey CSM regional monitoring centre.

Published in conjunction with the University of Liverpool Department of Clinical Pharmacology.

Editor: Helen Dingle. Telephone 0151 794 8122. E-mail druginfo@liv.ac.uk

Fluoroquinolones and tendon disorders

Fluoroquinolones and tendon disorders

Tendon disorders are a rare but well recognised class effect of the fluoroquinolone antibiotics. The mechanism for this reaction is not clear, although the sudden onset of some tendinopathies after a single dose suggests a direct effect on collagen fibres. In other cases, however, the reaction occurs months after the therapy is discontinued. Tendinitis usually resolves in around three weeks, but can persist for longer, while tendon rupture may take between one and six months to heal. 1 The CSM advises that fluoroquinolones are contraindicated in patients with a history of tendon disorders related to their use and should be discontinued immediately if tendinitis is suspected. Serious reactions are those that are:

•fatal or life threatening

•involve or prolong inpatient hospitalisation

•involve persistent or significant disability or

incapacity

•cause congenital abnormality

•are otherwise medically significant in your opinion … and serious reactions with

NSAIDs

The risk of tendon disorders appears to be higher in the elderly and in those on long-term steroid therapy. A recent analysis of a large UK General Practice Research database identified 704 cases of Achilles tendinitis and 38 cases of Achilles tendon rupture among a cohort of 46,776 patients who had used fluoroquinolones over a six-year period. 2 The relative risk for all tendon disorders with current use was 3.2 among patients aged 60 years or older and 0.9 among patients aged under 60 years. The risk was increased to 6.2

in patients over 60 years who were also taking corticosteroids.

The likelihood of inducing tendon lesions varies amongst the fluoroquinolones. Levofloxacin and ofloxacin may be more likely to do so than ciprofloxacin, norfloxacin and nalidixic acid, possibly due to differences in their chemical structures. 3

CSM Mersey has received 134 Yellow Cards reporting suspected adverse reactions to fluoroquinolones, including 23 reports for tendon disorders. More than half of these reactions occurred in the first 48 hours of treatment. The CSM Mersey reports are illustrated in the following table:

Drug Total

Reports

Tendinitis

Reports

No. aged

over 60

No.

taking

steroids

Ciprofloxacin 73 9 5 4

Levofloxacin 17 11 11 6

Ofloxacin 26 3 3 2

Others 18 0 - -

Haematopoetic 9%

Skin 7%

Cardiovascular 6%

Renal 5%

Respiratory 5%

Allergic 3%

Neurological 3%

Psychiatric 2%

Hepatic 2%

Others 2%

GI 57%

Tendinitis and Achilles tendon rupture are serious reactions and should be reported to the CSM via the Yellow Card Scheme.

CSM Mersey, Freepost, Liverpool, L3 3AB

http://www.liv.ac.uk/~druginfo/csm/ADR_Bulletin22.pdf