The Drug Safety Update is an NHS Evidence accredited provider
19 February 2010
The MHRA and CHM have published the February edition of Drug Safety Update This edition includes an article pointing out that tacrolimus products are not interchangeable without careful therapeutic monitoring. There is also an update on reports of suspected adverse reactions to flu antivirals and vaccines that indicates that the balance of risks and benefits remain positive. ‘Hot topics’ consider the safety of orlistat and the implications of a new indication of ‘harm reduction’ for nicotine replacement therapy. There is also a stop press article on the suspension of EU licences of sibutramine.
Drug Safety Update is an essential read for everyone whose professional practice involves medicines. It is published every month in electronic format only.
Tacrolimus is an immunosuppressant used to prevent organ transplant rejection. Prescribers are reminded to use licensed formulations of tacrolimus (Modigraf®▼, Prograf®, Advagraf®) where possible. However, as oral products can have different biovailabilities, they should not be considered interchangeable. Patients need to be monitored carefully by a transplant specialist when switching between different oral tacrolimus formulations (licensed or unlicensed) or regimens.
Tacrolimus is now available as Modigraf® granules, which can be used to prepare an immediate-release oral liquid, and can be considered for paediatric patients and others who have swallowing difficulties. This preparation has approximately 18% increased bioavailability to that of Prograf® capsules. Information on conversion between Prograf® and Modigraf® is given in the product information. Switching between Advagraf® and Modigraf® is not recommended.
Any suspected adverse reactions to tacrolimus products should be reported via the Yellow Card Scheme.
Swine flu portal update
Over 4 million doses of HINI (swine flu) vaccines (mainly Pandemrix®▼) were given as of January 17th 2010 in the UK, and there were 2817 reports of suspected adverse reactions up until 19th January. No new safety issues have been identified and the balance of risks and benefits remain positive. Most adverse reactions are neither serious nor long-lasting, and the isolated cases of serious adverse reactions may have been coincidental events; none of the deaths reported (18) were related to the use of the vaccine. There is also no evidence for any risks to pregnancy from using the vaccine.
More than 1.1 million treatment courses of oseltamivir (Tamiflu®▼) and more than 14,000 treatment courses of zanamivir (Relenza®▼) were given between July 23rd 2009 and January 12th 2010. There were 1,061 and 34 reports, respectively, of suspected adverse reactions as of January 19th. No new safety issues have been identified. Again, the balance of risks and benefits for these antivirals within their licensed indications remains positive, and there is no evidence that they carry any risks to pregnancy. The common suspected reactions are consistent with the signs and symptoms of flu-like illness, or are recognised side effects of these medicines.
Orlistat safety update
A Europe wide review of the safety information for alli® has led to a number of updates to its product information in line with that for Xenical®. Pharmacists need to be aware of this information so that they can appropriately advice consumers who wish to buy alli®. These relate to oxalate nephropathy, interaction with levothyroxine, interaction with antiepileptics, and pancreatis. Further information is available here.
Some counterfeit alli® products in the US have been found to contain sibutramine rather than orlistat. Although not found in the UK as yet, these counterfeit products may be available via the internet. Consumers are reminded not to buy medicines from unregulated websites.
A Europe-wide review of hepatic reactions with orlistat in July 2009, found insufficient evidence to show that orlistat is associated with more serious liver disorders than those already listed in the product information, and no further action was recommended. The MHRA, together with the European regulatory authorities, will continue to monitor all adverse reactions associated with orlistat. Any suspected reactions to orlistat should be reported via the Yellow Card Scheme.
Nicotine replacement therapy (NRT) and harm reduction
A new element has been added to the indication for NRT of ‘harm reduction’, since it has become widely accepted that there are no circumstances in which it is safer to smoke than to use NRT. Products with this new indication are expected to be on the market in 2010. The extension of the indication raises the question of the licensing of other unlicensed nicotine containing products on the market such as electronic cigarettes, which have not been assessed for safety, quality or efficacy. The MHRA has launched a public consultation on whether/how to bring these products into regulation. All comments are welcome and should be submitted to Amanda.firstname.lastname@example.org by 4th May 2010.
‘Stop press’ articles
These include the suspension of the EU licence for sibutramine, the risk of intraocular lens opacification with off-label intraocular use of recombinant tissue plasminogen activator, and suspected adverse reactions associated with intra-articular use of local anaesthetics.
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