Antihypertensive use before and after initiation of fixed-dose combination products in Australia: a retrospective study
- First Online:
Background National guidelines in Australia advise that patients should be stabilised on both individual antihypertensive medicines before initiating a fixed-dose combination (FDC) product. Objective The aim of this study was to examine the antihypertensive medicines use before and after initiation of four antihypertensive FDC products recently listed under the Australian Pharmaceutical Benefits Scheme—olmesartan or valsartan with hydrochlorothiazide, valsartan with amlodipine and ramipril with felodipine. Setting Australian veteran population Methods This was a retrospective cohort study using Australian Government Department of Veterans’ Affairs pharmacy claims data. Subjects initiating a FDC between 2008 and 2010 were included. Their antihypertensive medicine use was investigated in the 12-months prior to and post FDC product initiation. Main outcome measure Proportions of FDC initiators dispensed one or both of the individual medicines, or who had antihypertensive medicines other than the individual ones were assessed for the 12 months prior to initiation. For the post history, proportions of patients who continued the FDC as a sole therapy, had other antihypertensives co-administered with FDC, or ceased the FDC were established. Results 2,513 participants initiated one of the four FDC products in the study period. Immediately prior to FDC initiation, below 1 % had both individual medicines, 29 % had one of the individual medicines, 58 % had antihypertensive medicines other than the individual ones, and 12 % had no antihypertensive therapy. At 12 months post initiation, 25 % of the FDC initiators continued it as a sole treatment, 35 % required an additional antihypertensive medicine in addition to FDC product, and 40 % ceased the FDC. Conclusion A minority of patients initiated combination products after being stabilised on both individual medicines. Significant number had no prior history of antihypertensive use. One-third of FDC initiators still required additional antihypertensive medication concurrently with the FDC product at 12 months post initiation.
KeywordsAged Antihypertensive agents Australia Combination therapy Drug utilisation Elderly epidemiology Veterans
- 1.Cushman WC, Ford CE, Cutler JA, Margolis KL, Davis BR, Grimm RH, et al. Success and predictors of blood pressure control in diverse North American settings: the antihypertensive and lipid-lowering treatment to prevent heart attack trial (ALLHAT). J Clin Hypertens. 2002;4:393–404.CrossRefGoogle Scholar
- 4.Struijker-Boudier HA, Ambrosioni E, Holzgreve H, Laurent S, Mancia G, Ruilope LM, et al. The need for combination antihypertensive therapy to reach target blood pressures: what has been learned from clinical practice and morbidity–mortality trials? Int J Clin Pract. 2007;61:1592–602.PubMedCrossRefGoogle Scholar
- 12.Rabi DM, Daskalopoulou SS, Padwal RS, Khan NA, Grover SA, Hackam DG, et al. The 2011 canadian hypertension education program recommendations for the management of hypertension: blood pressure measurement, diagnosis, assessment of risk, and therapy. Can J Cardiol. 2011;27:415–33.PubMedCrossRefGoogle Scholar
- 17.Gangavati A, Hajjar I, Quach L, Jones RN, Kiely DK, Gagnon P, et al. Hypertension, orthostatic hypotension, and the risk of falls in a community-dwelling elderly population: the maintenance of balance, independent living, intellect, and zest in the elderly of Boston study. J Am Geriatr Soc. 2011;59:383–9.PubMedCrossRefGoogle Scholar
- 22.National Heart Foundation of Australia (National Blood Pressure and Vascular Disease Advisory Committee). Guide to management of hypertension 2008. Updated December 2010. National Heart Foundation of Australia; 2010.Google Scholar
- 23.National Prescribing Service. Managing hypertension as a cardiovascular risk factor. Strawberry Hills: National Prescribing Service Limited; 2007.Google Scholar
- 24.National Prescribing Service. Olmesartan medoxomil (Olmetec) monotherapy or in combination with hydrochlorothiazide (Olmetec Plus) for hypertension: National Prescribing Service Limited; 2007.Google Scholar
- 25.National Prescribing Service. Be aware of dose ranges for new ramipril with felodipine combination (Triasyn). National Prescribing Service Limited; 2007.Google Scholar
- 26.National Prescribing Service. Valsartan (Diovan) and combinations with hydrochlorothiazide (Co-Diovan) or amlodipine (Exforge). National Prescribing Service Limited; 2009.Google Scholar
- 27.Australian Prescriber. New combinations enalapril maleate/hydrochlorothiazide. Australian Prescriber. 2001;24: p 203.Google Scholar
- 28.Australian Government Department of Health and Ageing. Formulary allocations 1 Oct 2012. Canberra: Department of Health and Ageing; 2012 [cited 2012 Oct 29]; Available from: http://www.pbs.gov.au/info/industry/pricing/pbs-items/formulary-allocations.
- 29.Lloyd J, Anderson P. Australian institute of health and welfare. Veterans’ use of health services. Canberra: AIHW; 2008.Google Scholar
- 30.Australian Government Department of Veterans’ Affairs. Treatment population statistics December 2011. Canberra: Australian Government Department of Veterans’ Affairs; 2011.Google Scholar
- 31.WHO Collaborating Centre for Drug Statistics Methodology. The Anatomical Therapeutic Chemical Classification system. Oslo: WHO Collaborating Centre for Drug Statistics Methodology, Norwegian Institute of Public Health. 2012 [cited 2012 Oct 29]. Available from: http://www.whocc.no/atcddd/.