NHS Greater Glasgow & Clyde Area Drug and Therapeutics Committee
Greater Glasgow and Clyde Medicines
Medicines Update Primary Care

Medicines Update Primary Care July 2016

Zika Virus Update


The European Centre of Disease Prevention and Control (ECDC) stated that as of 7 July 2016, WHO has reported 62 countries and territories with mosquito-borne transmission since 2015. There is now a scientific consensus that Zika virus is a cause of microcephaly in babies and also Guillain-Barré syndrome an autoimmune neurological disease in adults. Most cases of Zika virus disease are spread by infected mosquitoes biting humans, however  eleven countries have reported evidence of person-to-person (male to female) transmission of Zika virus,  via a sexual route.
Key Points:
• Avoidance of mosquito bites should always be considered as the first line of defence against malaria and other mosquito-borne infections such as Zika virus.
• Unlike the mosquitoes that spread malaria, affected mosquitoes (the Aedes mosquito carrying Zika virus) are most active during the day, especially during mid-morning, then late-afternoon to dusk so prevention measures are advisable at all times of the day and night.
• Travellers returning from areas with ongoing Zika virus transmission should be advised to use a condom for at least 8 weeks after returning, in order to reduce the potential risk of onward sexual transmission. If before or during that period Zika virus symptoms occur, men should use condoms or consider abstinence for at least six months. See ECDC
• Pregnant women should consider avoiding travel to affected areas and any pregnant woman recently returned from such areas should consult medical advice.
• Insect repellant containing 50% DEET (N,N-diethyl-m-toluamide) will repel mosquitoes for approximately 12 hours.
•  Repellents containing 50% DEET can be used by pregnant women, but higher concentrations should not be used.
• When both sunscreen and DEET are required, DEET should be applied after the sunscreen. Sunscreen with a 30 to 50 SPF rating should be applied to compensate for DEET-induced reduction in SPF.
•  The use of DEET is not recommended for infants less than two months of age.
Detailed travel health advice is available for patients from the Scottish travel health service Fit for Travel and ECDC and also Travax for healthcare professionals.


Warfarin and Miconazole: MHRA Warning

A recent reminder from the MHRA warned healthcare professionals that miconazole, including the topical gel formulation, can enhance the anticoagulant effect of warfarin—if miconazole and warfarin are used concurrently, the anticoagulant effect should be carefully monitored and, if necessary, the dose of warfarin reduced.
Miconazole (Daktarin®, Daktacort®) is an antifungal indicated for prevention and treatment of various infections of the mouth, throat, skin, nails, or genitals. It is usually applied topically as a cream, ointment, powder, or oral gel. Patients who are taking warfarin should be reminded to consult their doctor or pharmacist before purchasing any medicine, including topicals and to seek medical advice if they notice signs of over-anticoagulation during treatment, such as sudden unexplained bruising, nosebleeds or blood in the urine.
Report interactions on a Yellow Card  to MHRA.


Valproate Abnormal Pregnancy: New Resources

 
Recently the Medicines and Healthcare products Regulatory Agency (MHRA) published information and strengthened warnings around the safety of medicines related to valproate (sodium valproate, valproic acid and valproate semisodium). Children exposed to valproate in utero are at high risk of developmental disorders and congenital malformations. Refer to the Medicines Update blog published last year for further information. Further information has been issued to improve awareness.
What’s new?
New communication materials are now available to use with female patients when prescribing valproate. Healthcare professionals are advised to use the new communication materials to support discussion of the risks with women of childbearing potential and girls who take valproate.
The materials consist of:
• A booklet for healthcare professionals
• A consultation checklist
• A patient guide
• A patient card
All materials can be ordered directly from Sanofi by calling 0845 372 7101.
Key messages for GP's
• Do not initiate valproate in this patient group. Valproate should be started and supervised by a specialist experienced in managing epilepsy or bipolar disorder.
• Consider the need to arrange treatment reviews with the relevant specialist for women of childbearing potential and girls who are currently taking valproate.
• If a woman who is taking valproate tells you she is pregnant or would like to have a baby, refer her to the specialist responsible for her care.


Valsartan: Shortage

There are again supply problems with valsartan products. Advice from May 2014 suggests where a patient is unable to obtain their normal valsartan prescription; prescribers may need to consider switching patients to an alternative Angiotensin-2 receptor antagonist (A2RA).
Valsartan is licensed for:
 Hypertension – all eight A2RAs on the UK market are licensed for hypertension. 
Heart Failure - candesartan and losartan are licensed for heart failure and are the preferred list options in the NHSGGC Formulary.
Post-MI with left ventricular failure or left ventricular systolic dysfunction (LVSD) – there are no other A2RAs licensed for use in the post-MI setting and specialist advice should be sought before switching to an alternative.
There is no information on direct dose-equivalences of A2RAs, the table below provides approximate conversions for the Formulary preferred list options. When changing from one drug to another, consideration should be given to where on the dosing range the current dose falls, i.e. bottom, middle or top of range.  If switching from a twice daily valsartan dose to a once daily dose of an alternative such as losartan or candesartan, the patient should be advised of this to reduce the risk of a dosing error.

 

A2RA Approximate dosage conversions
Valsartan 40mg daily * 80mg daily * 160mg daily * 320mg daily *
Candesartan 4mg daily 8mg daily 16mg daily 16-32mg daily
Losartan** 25mg daily 50mg daily 100mg daily  

* Dose may be given as two divided doses.

** The target dose of losartan for heart failure is 150mg daily if tolerated.
Acknowledgement: Yuet Wan, London and South East Regional Medicines Information Service


Creon® (pancreatin) 40,000:Shortage

Creon® 40,000 strength is out of stock and there is no indication when it will next be available. The lower dose Creon® 25, 000 has recently become available again and also Creon® 10, 000 products remain available. It is recommended that an equivalent dose of a lower strength be prescribed. Please see the table below for equivalent dosages.
As with all changes to pancreatin usage, dosage should be adjusted according to size, number and consistency of stools so that the patient thrives.

 

Creon 40000 dose (number capsules) Approx Creon 25000 dose (number capsules) Approx Creon 10000 dose (number capsules)
1 2 4
2 3 8
3 5 12
4 7 16
5 8 20
6 10 24

 

Sign 148: Patient Information on Acute Coronary Syndrome


A patient booklet that accompanies the guideline SIGN 148 Acute Coronary Syndrome was published on 20 June 2016. The booklet is for patients, and the carers and families of patients, who have been admitted to hospital with a suspected heart attack or unstable angina on admission to hospital. It provides information on assessment and investigation, treatments during the first 12 hours and continuing investigation and treatment.
http://www.sign.ac.uk/pdf/PAT148.pdf