Regulator urges GPs to switch clopidogrel patients off PPIs
By Nigel Praities
GPs must consider switching the gastroprotective medication of hundreds of thousands of patients after the European drug regulator warned of a ‘significant interaction' between proton pump inhibitors and clopidogrel.
The European Medicines Agency warned PPIs as a class could make clopidogrel less effective and place patients at increased risk of heart attack or stroke.
The UK medicines regulator has also issued advice to GPs, urging a review of the prescribing of PPIs at the next appointment for patients taking clopidogrel.
‘Concomitant use of a PPI with clopidogrel is not recommended unless considered essential,' the MHRA advises.
Around 460,000 patients in the UK are currently prescribed clopidogrel and around half are also prescribed PPIs, according to figures obtained by Pulse from Cegedim Strategic Data.
A substantial number may also be taking over-the-counter omeprazole independently, as heartburn and stomach ulcers are side-effects of clopidogrel.
The MHRA advises GPs to check patients who are taking clopidogrel are not buying omeprazole over-the-counter.
The warning comes after the recent publication of three major studies showing an interaction between PPIs and clopidogrel. One published just last month showing a 51% increase in the risk of hospitalisation for cardiovascular event in patients on clopidogrel on PPIs, compared with those not taking the drugs.
‘These studies suggest a significant interaction might occur between clopidogrel and members of the PPI class, making clopidogrel less effective,' the EMEA statement reads.
The EMEA has recommended the product information for all clopidogrel-containing medicines should change to discourage concomitant use with PPIs.
Dr Jamie Dalrymple, chair of the Primary Care Gastroenterology Society and a GP in Norwich, said it was a serious interaction that could affect many patients.
‘Potentially we could be talking about a substantial number of patients.
‘I can understand the concern about the interaction, as patients who have had a coronary artery stent have a 40% chance of blockage of the stent if clopidogrel is ineffective,' he said.
Dr Dalrymple advised GPs consider prescribing alternatives: ‘Some H2RAs such as ranitidine should be effective as gastroprotection and not interact with clopidogrel.'
A spokesperson from the manufacturers of clopidogrel said they were aware of the problem and were conducting research to better understand the interaction.
‘Sanofi-aventis and Bristol-Myers Squibb are in the process of implementing similar changes to product information with health authorities around the world,' the spokesperson said.Advice on potential interaction
- The need for PPI therapy in patients who are also taking clopidogrel should be reviewed at their next appointment: only use these medicines concomitantly when essential
- Prescribe PPIs strictly in line with their licensed indications
- Check that patients who are taking clopidogrel are not buying over-the-counter omeprazole
Source: MHRA, June 2009