The Editorial Executive Committee welcomes letters, which should be less than 250 words. Before a decision to publish is made, letters which refer to a published article may be sent to the author for a response. Any letter may be sent to an expert for comment. When letters are published, they are usually accompanied in the same issue by their responses or comments. The Committee screens out discourteous, inaccurate or libellous statements. The letters are sub-edited before publication. Authors are required to declare any conflicts of interest. The Committee's decision on publication is final.

Letter to the editor

Editor, – In reference to the article 'Flying and thromboembolism' (Aust Prescr 2009;32:148-50), is there any place for rivaroxaban currently only listed for major orthopaedic surgery in high-risk long-haul flight patients? If so, at what dosage and for how long? These patients would previously have been offered subcutaneous low molecular weight heparin.

Mick Coward
Medical Adviser
The Travel Doctor - Traveller's Medical and Vaccination Centre
Adelaide

Author's comments

Associate Professor Frank Firkin and Associate Professor Harshal Nandurkar, authors of the article, comment:

There has been no official approval in Australia for low molecular weight heparin for prophylaxis in high-risk subjects on long-haul flights. Its use for this purpose is based on extrapolation from its proven efficacy in thromboembolism prophylaxis in major hip and knee joint surgery, when the venous thromboembolic risk is generally viewed as greater than that posed by a long-haul flight.

Oral rivaroxaban has been shown to be at least as effective as low molecular weight heparin for thromboembolism prophylaxis in major hip and knee joint surgery, and can be viewed as at least as effective for prophylaxis in long-haul flights, with the obvious advantage that it is an oral drug. However, this is a non-approved purpose as is the case with low molecular weight heparin. Prescribers should be aware of the risks associated with using rivaroxaban in patients with renal impairment or liver disease, and that other drugs may affect its metabolism. These issues are addressed in this issue of Australian Prescriber and in the August 2009 issue of RADAR.

First published online 1 April 2010