Key points on fixed-dose combination medicines
Prescribers are increasingly faced with a range of fixed-dose combination medicines (FDCs) as an option in place of individual components prescribed separately. Switching patients from individual medicines to fixed-dose combination medicines must be done judiciously taking the following into consideration:
Assess patient’s need
- Evidence for improved adherence with combination medicines is strongest when the reduction in pill burden is greatest1,2
Assess the level of complexity involved in a patient's medicine regimen before choosing fixed-dose combination therapy.
- A large number of factors contribute to non-adherence3
Do not choose fixed-dose combination therapy solely on the possibility of improved adherence, convenience or cost advantages of the preparation.
- Will the benefits outweigh the risks?
Table 1. Benefits and risks of fixed-dose combination medicines
Decreased pill burden
Being unable to adjust the doses of individual components in specific patients7,8
Misidentifying the causative medicine when the patient experiences side effects
Over- or under-dosing
- It is best to start and stabilise patients on the individual components before starting the corresponding fixed-dose combination medicine9
This facilitates adjustment of dose based on response and monitoring of adverse effects.
- Be alert to unintended double- or under-dosing at the time of switching and discuss this with the patient
show patients which medicines are being replaced by the combination medicine. Encourage them to use and maintain a Medicines List to keep track of the active ingredients as well as the brand names of their medicines.
- Identify which component(s) in a fixed-dose combination are responsible for adverse effects if they occur
Watch for signs and symptoms specific to individual components.
- Patients taking fixed-dose combination medicines may be eligible for a Home Medicines Review
Patients at risk of medicines-related problems are:
- those taking five or more regular medicines
- those taking more than 12 doses of medicine a day
- those who have had a significant change to their medicine regimen in the past 3 months or who have symptoms of an adverse drug reaction.10
For more information
- Definition of fixed-dose combination medicines
- Place in therapy of fixed-dose combination medicines
- Indications for fixed-dose combination medicines
- Prescribing tips for fixed-dose combination medicines
- Adverse effects of fixed-dose combination medicines
- Resources on fixed-dose combination medicines for your patients
- Moulds RFW. Combination products – love them or loathe them? Aust Prescr 2001;24:127–9. [Full text]
- Llibre JM, Arribas JR, Domingo P, et al. Clinical implications of fixed-dose coformulations of antiretrovirals on the outcome of HIV-1 therapy. AIDS 2011;25:1683–90. [PubMed]
- Australian Government Department of Health and Ageing. Compliance Medicines Working Group Report to Pharmaceutical Benefits Advisory Committee. April 2010. [Online] (accessed 11 December 2012).
- Simons LA, Ortiz M, Calcino G. Persistence with a single pill versus two pills of amlodipine and atorvastatin: the Australian experience, 2006–2010. Med J Aust 2011;195:134–7. [PubMed]
- Gupta AK, Arshad S, Poulter NR. Compliance, safety, and effectiveness of fixed-dose combinations of antihypertensive agents: a meta-analysis. Hypertension 2010;55:399–407. [PubMed]
- Bangalore S, Kamalakkannan G, Parkar S, et al. Fixed-dose combinations improve medication compliance: a meta-analysis. Am J Med 2007;120:713–9. [PubMed]
- Alphapharm Pty Limited. Glucovance. 2010. [Online] (accessed 9 October 2013).
- Merck Sharp & Dohme (Australia) Pty Limited. Juvicor Product Information. 2012. [Online] (accessed 28 February 2013).
- Gadzhanova S, Gillies M, Roughead E, et al. Fixed dose combination diabetes medicines - usage in the Australian veteran population. Aust Fam Physician 2011;40:811–5. [PubMed]
- Australian Government Department of Health and Ageing. Home Medicines Review (HMR). 20 August 2013. [Online] (accessed 9 October 2013).