The National Prescribing Centre has published MeReC Extra 41 (PDF) which covers several areas.
The interaction between clopidogrel and proton pump inhibitors is discussed in relation to the current advice and with due consideration of the advice from the National Institute for Health and Clinical Excellence (NICE) about the appropriate place in therapy for clopidogrel.
Clinicians are also reminded of the unit change for HbA1c and the partial update the NICE Guideline for Diabetes. Standard global reporting of HbA1c will result in a transition from the % scale to a mmol/mol by 2011. The updated NICE guideline contains revised advice about the management of blood glucose with newer hypoglycaemic agents.
Finally, the link between cancer and long-acting human insulin analogue usage is discussed. The association between some types of cancer and use of these insulin analogues is being investigated further at the request of regulatory authorities. Prescribing data indicate that approximately 40% of all intermediate/long-acting insulin items are for glargine or detemir despite NICE recommendations that these agents are not be used routinely.
Action: Clinicians who see patients with cardiovascular disease or diabetes will find this information useful and informative.
The Lancet has published the results of an analysis of two randomised controlled trial to review the effect size of the interaction between clopidogrel (Plavix®) and proton pump inhibitors (PPIs).
In the PRINCIPLE-TIMI 44 trial the primary outcome assessed inhibition of platelet aggregation at six hours by light-transmission aggregometry in 201 patients assigned to treatment with high dose clopidogrel or prasugrel. Inhibition of platelet aggregation was significantly lower for patients on a PPI and clopidogrel. The effect was not statistically significant for patients assigned to prasugrel.
In the TRITON-TIMI 38 trial the primary endpoint was the composite of cardiovascular death, myocardial infarction or stroke. 13,608 patients with an acute coronary syndrome were assigned to treatment with clopidogrel or prasugrel. 4,529 patients were on a PPI at randomisation. There was no association between PPI use and an increased risk of the primary endpoint for either study drug.
The authors of the study conclude that, "current findings do not support the need to avoid concomitant use of PPIs, when clinically indicated, in patients receiving clopidogrel or prasugrel". However, they also note limitations in their analysis. PPI usage was not randomised and residual confounding is possible despite multivariate adjustment. PPI usage data were collected at baseline and may have changed through the study and these analyses are both post-hoc.
Action: The Medicines and Healthcare products Regulatory Agency have advised clinicians have to avoid the combination of clopidogrel and PPI where possible. These data provide some reassurance that clinical efficacy may not be affected if the combination is unavoidable.
The Scottish Medicines Consortium (SMC) has issued its monthly advice on new medicines.
Etoricoxib (Arcoxia®) has been rejected for the treatment of ankylosing spondylitis. The manufacturer failed to make a submission.
Brinzolamide/timolol eye drops (Azarga®) has been accepted for the treatment of raised intraocular pressure (IOP) in adult patients with open-angle glaucoma or ocular hypertension for whom monotherapy provides insufficient IOP reduction. It was noted that the combination product allows patients to administer fewer drops at a modestly increased cost over separate administration of the constituents.
Action: Clinicians should be aware of the recommendations of the SMC. Routine use of rejected and restricted medicines should be avoided.
Tafluprost unit dose eye drops (Saflutan®) have been launched for the treatment of raised intraocular pressure in open angle glaucoma and ocular hypertension. These are the first prostaglandin analogue eye drops to be made available in a preservative free formulation. The summary of product characteristics is now available online.
This product may offer an advantage in patients who would benefit from treatment with a prostaglandin analogue but who are allergic to preservatives however it is more expensive than existing options, subject to more intensive monitoring for safety reasons and it is not currently available in combination with other ocular antihypertensive agents. (Prices below from BNF57 and manufacturer communication).
- Tafluprost 30 x 0.3ml unit dose containers - £17.41
- Latanoprost 2.5ml eye drops - £13.14
- Bimatoprost 3ml eye drops - £11.46
- Travoprost 2.5ml eye drops - £10.50
Action: Clinicians should be aware of this new product. The potential advantage of a preservative free formulation should be balanced against the risks of using a less well established product.
The National Prescribing Centre has published four patient decision aids (PDAs) that can be used during consultations to help patients decide whether they want to take antiviral medication for the treatment of influenza like illness.
The four PDAs cover different patient populations as follows:
- At-risk children and adolescents
- Otherwise healthy children younger than 13 years
- At-risk adults
- Otherwise healthy adults (13 to 64 years)
PDAs aim to present risk and benefit information visually to patients in order to allow them to make a decision to accept or refuse a specific treatment. They may prove useful in the coming months if the expected second wave of swine 'flu (H1N1) occurs.
Action: Clinicians should be aware of the availability of these PDAs and make use of them where they will aid patient decision making.