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Memo – shortage of supply
To:
From:
Date:
Re: Valsartan products
Description of product affected
Capsules and tablets are available as 40mg, 80mg and 160mg strengths (tablets also available as 320mg strength).
Background
Valsartan is licensed for the treatment of patients with hypertension, symptomatic heart failure; and after a recent (12 hours to 10 days) myocardial infarction (MI) in patients who develop symptomatic heart failure or asymptomatic left ventricular systolic dysfunction. The licensed dose ranges from 40 to 320mg per day given as a once or twice daily dose depending on indication.1 It is one of several angiotensin II receptor antagonists (A2RAs) on the UK market which are all licensed for the treatment of hypertension, but differ in their other licensed indications.
Why we are providing this information
Several suppliers are experiencing intermittent supply issues with valsartan products which may last several months. This includes both capsules and tablets.
Implications for patient care
Clinicians may, in some cases, need to consider switching patients to an alternative A2RA.
Management options
Of the seven other A2RAs on the UK market, losartan and candesartan (available as generic medicines) are the only ones licensed for the treatment of both hypertension and heart failure, the most common indications for this group of drugs. The licensed dose for losartan ranges from 12.5mg to 100mg for hypertension, and to 150mg for heart failure, given as a once daily dose. It is available as 12.5, 25, 50, and 100mg tablets.2 For candesartan, the licensed dose ranges from 4mg to 32mg given as a once daily dose, and it is available as 2, 4, 8, 16 and 32mg tablets.3 Information on dose equivalence of A2RAs is not available, so when changing a patient from one A2RA to another, the dosing range within which the dose falls should be taken into account (i.e. bottom, middle or top of the dosing range). It should be noted that valsartan is the only A2RA licensed for use in the post MI setting and specialist advice should be sought if alternative A2RA is required. In addition, patients on a twice daily dosing regimen of valsartan will need to be advised of a change to a once daily regimen on switching to an alternative A2RA, to reduce the risk of a dosing error.
A2RA / Approximate dose conversions*Valsartan / 40mg DAILY§ / 80mg DAILY§ / 160mg DAILY§ / 320mg DAILY§
Candesartan / 4mg OD / 8mg OD / 16mg OD / 16mg OD to 32mg OD(
Losartan / 25mg OD / 50mg OD / 100mg OD ( / -----
*Dose equivalencies are approximate and individual responses may vary so blood pressure should be monitored following the switch and dosing adjusted accordingly, if needed.4
§ Dose may be given as two divided doses depending on indication
References
1. Novartis Pharmaceuticals UK Ltd. Diovan Capsules (valsartan). SPC (DOR 02/11/12)
2. Merck Sharp & Dohme Limited. Cozaar (losartan) Film-Coated Tablets. SPC (DOR January 2014)
3. Takeda UK Ltd. Amias Tablets (candesartan cilexetil). SPC (DOR 21/11/13)
4. Therapeutic Research Center. Angiotensin Receptor Blocker (ARB) Antihypertensive Dose Comparison (Full update February 2012). Prescriber's Letter 2012; 28 (3):280322
Original document prepared by:
Guy’s and St Thomas’ NHS Foundation Trust Medicines Information Centre
Prepared 10th March 2014
Acknowledgement
Helen Williams, Consultant Pharmacist for Cardiovascular Disease, Southwark Health and Social Care / South London Cardiac and Stroke Networks
Document modified by:
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Name of person at base hospital where memo is circulated (i.e. NOT the original author at Guy’s and St Thomas’ NHS Foundation Trust
Disclaimer: The content of some of this memo is based on consensus opinion from clinical practitioners. Users should bear this in mind in deciding whether to base their policy on this document.