Generic medicines - informing patients about multiple brands

Published in MedicineWise News

Date published: About this date

Clinical content may change after this date. This information is not intended as a substitute for medical advice from a qualified health professional. Health professionals should rely on their own expertise and enquiries when providing medical advice or treatment.

Generic medicines are widely used in Australia and account for around 40% of prescriptions filled on the Pharmaceutical Benefits Scheme (PBS).1 While GPs and pharmacists agree with consumers having a choice of medicine brands2-4, many health professionals remain concerned that switching between brands may confuse some patients, particularly if done repeatedly.3-5 This NPS News highlights ways to minimise confusion and addresses common misconceptions about the safety and effectiveness of generic medicines.

Minimising patient confusion

Patient confusion caused by switching between brands of a medicine is a major concern for health professionals.2-4 While the extent of confusion is unknown, cases of double dosing, stopping medicines and reduced recognition of dispensing errors have been attributed to brand switching, with some leading to patient harm.5-9

Inform patients they may be offered a choice

Although patients are more likely to discuss generic medicines with their pharmacist10, they also value their GP telling them that they may be offered a generic medicine.11-13 Information from both prescribers and pharmacists can help allay patients’ concerns about generic medicines and help them feel more confident in their choice (see Box 1).11-13

Use the active ingredient name

Educating patients about the active ingredient name (that is, the drug or ‘generic’ name) and using it consistently can help reduce confusion over brand names.14,15 This is particularly important for patients discharged from hospital who may receive unfamiliar brands.14 Encourage patients to use a Medicines List to record the active ingredient name of their medicine, as well as other important information.15

Box 1: Discussing medicine brands at the time of prescribing

Use the active ingredient name instead of the brand name when discussing a medicine and what it is for.

Explain that the active ingredient is the chemical that makes the medicine work and is the name to look for on the prescription label and the medicine container.

Explain that there may be more than one brand name for their medicine and that they all work just as well.

If brand substitution is acceptable, tell patients:

  • that they may be offered a choice of brands at the pharmacy.
  • that they can choose a different brand from the one you prescribed.
  • to ask their pharmacist if they have any questions about switching between brands of medicines.

Ensuring safe switching

GPs, nurse practitioners and pharmacists can help prevent confusion about medicine brands by knowing when switching is permitted and safe (see below) and by discussing medicine brands with patients and carers (see Boxes 1 and 3).15-17

When is switching permitted?

Only offer an alternative brand if the medicines are listed as interchangeable on the PBS (see Box 2), the switch is safe for the individual (see below) and the prescriber allows it. Only switch brands if the patient or carer consents to it — it is their choice.17

Box 2: Finding an interchangeable brand or the active ingredient

Prescribing software 

Some programs allow you to enter the original brand of a medicine then view alternatives, including interchangeable brands (e.g. by clicking the ‘Equivalent products’ button in Best Practice or ‘Brands’ button in Medical Director 3). The active ingredient also appears allowing you to prescribe without nominating a brand. Note that brands not registered as bioequivalent, and other formulations, can also appear on these lists.

PBS schedule

Search by active ingredient or original brand, then look for ‘a’ or ‘b’ in the ‘Brand name & manufacturer’ field. Brands marked ‘a’ can be substituted for others marked ‘a’, while those marked ‘b’ can be substituted for others marked ‘b’. Brands marked ‘a’ cannot be substituted with brands marked ‘b’ or vice versa. Alternatively, go to ‘Browse by Brand Premium’, which shows brands that are interchangeable with the original brand and their costs.

Dispensing software

Most dispensing software programs have PBS updates loaded monthly and are connected to PBS online.

Take particular care with some groups

People at risk of confusion. People who have complex medicine regimens, cognitive or vision impairment or who do not have English as their first language may be confused by a brand switch and be at risk of double dosing.8,18 Check that the patient (or carer) understands which medicine is being replaced and what it is for, and can recognise its active ingredient — if in doubt, don’t switch brands.

People who are taking a critical dose (or narrow therapeutic index) medicine.A Some critical dose medicines (e.g. warfarin, phenytoin, lithium) do not have a bioequivalent brand and switching is not an option. For those medicines that do (e.g. cyclosporin, digoxin, thyroxine) avoid switching brands without consulting the prescriber; prescribers are best placed to discuss choice of brands with patients to minimise the risk of adherence problems.

People with an intolerance to or a specific concern about an inactive ingredient (or excipient). If a person has a known significant intolerance to an inactive ingredient (e.g. lactose, gluten, colours) or a religious or cultural concern about one (e.g. gelatin) — check the list of inactive ingredients in the consumer medicine information leaflet of the replacement brand before offering it.

Other patient factors. Switching may not suit people for whom a lack of consistency in the medicine brand may reduce adherence (e.g. people with a mental illness).19

A. These are medicines for which even a small change in blood concentration can lead to a significant loss of efficacy or an increase in adverse effects.18

Communication is an essential safeguard

Most pharmacies have policies on substituting generic medicines.4 Pharmacy policies on brand switching help ensure all patients and carers are asked for consent and are given suitable information to make their choice (Box 3), including any necessary advice or resources (Box 4).17

Always discuss differences in appearance

Changes to the appearance of a person’s tablets or their packaging can be a major source of confusion.6,12 When discussing a brand switch of a medicine with a patient or carer, explain the visual differences in packaging and/or the formulation (see Box 3). This is particularly important for people from a non-English speaking background and older people, who may rely on colours and shapes to identify their medicines.8,20

Box 3: Tips for pharmacists and pharmacy assistants

Use the active ingredient name and show patients where it is on the prescription label and medicine packaging.

Inform patients if there is more than one brand of their medicine.

Encourage patients to use a Medicines List to record the active ingredient name and the brand name of their medicines.

When offering an alternative brand:

  • discuss the benefits of choosing it (e.g. cost saving, availability) and any disadvantages (e.g. difference in appearance)
  • check the suitability of it for the patient (e.g. personal preference, known intolerance to inactive ingredients)
  • explain that it may differ in shape, size or colour, but it’s the active ingredient that matters.

When a patient consents to a switch:

  • use Label 15 [This medicine replaces … Do not use both]
  • advise the patient not to start the new brand until the old one is finished
  • point out the differences in appearance of the replacement brand.

Avoid multiple switches

Most GPs and pharmacists agree that consistent supply of brands is important for patients on long-term therapy.2,3 Of particular concern is that some patients can become confused by having different brands of the same medicine dispensed on the repeats of their prescription.2,3 Although a link between patient harm and multiple switching has not been established, multiple switching does occur.21,22 A study of PBS claims from 2008 found that up to 24% of concession card holders had the brand of one of their long-term medicines switched more than once within a year.21

Encourage patients to stay with one prescriber and one pharmacy—this may lower the chance of multiple switching.22,23 At the pharmacy, if the same brand of a long-term medicine is unavailable, always inform the patient or carer and ask for their consent before switching brands (see Box 3).17

Box 4: Resources to help patients know what they are taking

Why are we offered a choice of medicine?
Patient leaflet
Explains the importance of knowing the active ingredient and where to find it on medicine labels. Available in several languages.
Download a pdf of the brochure
Medicine lists Useful way for patients to keep track of their medicines. The NPS Medicines List is available in several languages and can be ordered in bulk. Patients can also download and print a copy or download the Medicines List app.
Medicines Line National phone service for consumers that provides information on medicines. 1300 MEDICINE (1300 633 424), Monday to Friday 9am to 5pm EST (excluding NSW public holidays).
Home Medication Review (HMR) Recommended for people at risk of medicine mix-ups or poor adherence. For more information, go to the Medicare Australia Home Medicines Review web page.

Are generic medicines as effective and safe as original brands?

While Australian GPs seldom disallow brand substitution24,25, doubts about generic medicines persist.2-4 A 2008 national survey of GPs found 21% agreed with the statement that ‘‘generic medicines are not always as effective as branded medicines’’, while a further 32% were undecided.3

Generic medicines meet the same standards 

The Therapeutic Goods Administration (TGA) requires that generic medicines meet the same quality criteria and manufacturing standards as original brands.26 The TGA also requires evidence of bioequivalence — that is, a generic medicine must have an equivalent drug plasma-concentration profile to the original brand or market leader.26

This means that while generic medicines may cost less than original brands, they are equivalent in dosage form, safety, strength, route of administration, quality, bioavailability and intended use.8,27 If a medicine is listed on the PBS as interchangeable, this means it is accepted as being bioequivalent by the TGA.

Generic medicines can have inactive ingredients that are different from those in the original product but these must also meet the TGA’s quality and safety criteria.18

Does bioequivalence guarantee clinical equivalence?

Using bioequivalence as a surrogate for equivalent clinical effectiveness is internationally recognised and supported by trial data. A review of 38 clinical trials comparing the effect of generic and brand-name cardiovascular drugs found no evidence that brand name drugs were more clinically effective than generic drugs.28

What is the bioequivalence standard?

The standard method accepted by the TGA and regulators in other countries is a clinical study with a cross-over design.29,30 The approach is also widely used in drug development for comparing clinical trial formulations with the marketed version.31

The method involves healthy volunteers (or patients) receiving the original or generic product on separate occasions, then the rate and extent of drug absorption are compared by measuring:

  • the time taken for maximum plasma concentration (Tmax)
  • the maximum plasma concentration (Cmax)
  • the area under the plasma concentration–time curve (AUC)

The generic:original product ratios and 90% confidence intervals (CI) are calculated for each parameter. Two products are considered bioequivalent if the 90% CIs fall within specified limits (0.8 to 1.25)29, which usually occurs when the ratios are less than 10% of one another.32

The robustness of this standard has been evaluated in a US Food and Drug Administration review which found the average difference in Cmax and AUC ratios for generic and innovator products was 4.4% and 3.6%, respectively.33

Why do they cost less?

A common misconception is that generic medicines are less expensive than original brands because they have inferior ingredients or are manufactured to lesser standards.11 However, the costs of ingredients and manufacturing are typically similar.34

Generic medicines can be sold for less because suppliers do not need to recoup the large costs of research, development and marketing of the original brand. Generic products are marketed by both innovator and generic medicines companies.35 Increased use of generic medicines stimulates price competition among manufacturers and lowers the price to the purchaser (that is, to the healthcare system and/or to the consumer).8

Expert Reviewers

Prof Andrew McLachlan, Faculty of Pharmacy, University of Sydney, NSW

Dr Geoff Spurling, GP, Inala QLD

Reviewers

Dr John Dowden, Editor, Australian Prescriber

Dr Graham Emblen, GP, Toowoomba

Dr Sarah Gani, GP and Medical Educator, Blacktown

Benafsha Khariwala, Managing Editor, Journal of Pharmacy Practice and Research

A/Prof Jennifer Martin, Head PA-Southside Clinical School

Deborah Norton, QUM Pharmacist, West Vic DGP

Simone Rossi, Managing Editor, Australian Medicines Handbook

Any correspondence regarding content should be directed to NPS. Declarations of conflicts of interest have been sought from all reviewers.

References
  1. Centre for Strategic Economic Studies. The impact of PBS reforms on PBS expenditure and savings: acutal and projected from 2008–09 to 2017–18. Melbourne: Victoria University, 2009.
  2. National pharmacists survey: final report. Sydney: National Prescribing Service Limited, 2008.
  3. National general practitioner survey: final report. Sydney: National Prescribing Service Limited, 2008.
  4. Ping CC, March G, Clark A, et al. A web-based survey on Australian community pharmacists' perceptions and practices of generic substitution. J Generic Med 2010;7:342–53.
  5. Hassali MA, Kong DCM, Stewart K. Generic medicines: perceptions of general practitioners in Melbourne, Australia. J Generic Med 2006;3:214–25.
  6. Emery J, McKenzie A, Bulsara C, Holman D. Controversy over generic substitution. BMJ 2010;341:c3570.
  7. Hakonsen H, Toverud EL. Special challenges for drug adherence following generic substitution in Pakistani immigrants living in Norway. Eur J Clin Pharmacol 2011;67:193–201.
  8. Hattingh HL, Maganlal S, King MA. The impact on community pharmacy of the changing generic medicine substitution landscape. J Law Med 2010;17:761–71.
  9. Pharmaceutical Health and Rational Use of Medicines. Consumer perspectives on managing multiple medicines: a summary of consumer consultations conducted by the Pharmaceutical Health and Rational use of Medicines (PHARM) Consumer Sub-Committee during 1998–2000. Canberra, 2001.
  10. Evaluation of the generic medicines campaign 2008–2009 TVC1 and TVC2. Sydney: National Prescribing Service Limited, 2009.
  11. Hassali MA, Kong DCM, Stewart K. Generic medicines: perceptions of consumers in Melbourne, Australia. Int J Pharm Pract 2005;13:257–64.
  12. Bulsara C, McKenzie A, Sanfilippo F, et al. 'Not the full Monty': a qualitative study of seniors' perceptions of generic medicines in Western Australia. Aust J Prim Health 2010;16:240–5.
  13. Consumer tracking research: changes in generic medicine usage & attitudes. Sydney: Stancombe Research & Planning, 2005.
  14. Guiding principles to achieve continuity in medication management. Canberra: Australian Pharmaceutical Advisory Council, July 2005.
  15. McLachlan AJ. Generic medicines literacy - minimising the potential for patient confusion [Editorial]. Med J Aust 2010;192:368–9.
  16. Code of Professional Conduct. Canberra:Pharmaceutical Society of Australia, 1998. (accessed 11 August 2011).
  17. Guidelines for Pharmacists on PBS Brand Substitution. Canberra: Pharmaceutical Society of Australia, July 2004.
  18. McLachlan AJ, Ramzan I, Milne RW. Frequently asked questions about generic medicines. Aust Prescr 2007;30:41–3.
  19. Greene JA, Kesselheim AS. Why do the same drugs look different? Pills, trade dress, and public health. N Engl J Med 2011;365:83–9.
  20. Kamerow D. The pros and cons of generic drugs. BMJ 2011;343:d4584.
  21. Ortiz M, Simons LA, Calcino G. Generic substitution of commonly used medications: Australia-wide experience, 2007-2008. Med J Aust 2010;192:370–3.
  22. Kalisch LM, Roughead EE, Gilbert AL. Pharmaceutical brand substitution in Australia: Identifying factors associated with having multiple brand substitutions. Int J Pharm Pract 2009;17:339–44.
  23. Kalisch LM, Roughead EE, Gilbert AL. Brand substitution or multiple switches per patient? An analysis of pharmaceutical brand substitution in Australia. Pharmacoepidemiol Drug Saf 2008;17:620–5.
  24. Chong C, March G, Clark A, et al. A nationwide study on generic medicines substitution practices of Australian community pharmacists and patient acceptance. Health Policy 2011;99:139-48.
  25. Newby D, Robertson J. Computerised prescribing: assessing the impact on prescription repeats and on generic substitution of some commonly used antibiotics. Med J Aust 2010;192:192–5.
  26. Therapeutic Goods Administration. Australian regulatory guidelines for prescription medicines, June 2004.  Department of Health and Ageing. (accessed 30 August 2011).
  27. U.S. Food and Drug Administration. Generic drugs: questions and answers. Last updated 24/08/2011. (accessed 30 August 2011).
  28. Kesselheim AS, Misono AS, Lee JL, et al. Clinical equivalence of generic and brand-name drugs used in cardiovascular disease: a systematic review and meta-analysis. JAMA 2008;300:2514–26.
  29. European Medicines Agency (Committee for medicinal products for human use). Guideline on the investigation of bioequivalence. London: European Medicines Agency, 2010. (accessed 30 August 2011).
  30. Holmes DR, Jr., Becker JA, Granger CB, et al. ACCF/AHA 2011 Health Policy Statement on Therapeutic Interchange and Substitution: A Report of the American College of Cardiology Foundation Clinical Quality Committee. Circulation 2011.
  31. Birkett DJ. Generics - equal or not? Aust Prescr 2003;26:85–7.
  32. BPACNZ. Best practice: generic medicines. Best Practice J;July 2009.
  33. Davit BM, Nwakama PE, Buehler GJ, et al. Comparing generic and innovator drugs: a review of 12 years of bioequivalence data from the United States Food and Drug Administration. Ann Pharmacother 2009;43:1583–97.
  34. Lofgren H. Generic drugs: international trends and policy developments in Australia. Aust Health Rev 2004;27:39–48.
  35. Probyn AJ. Some drugs more equal than others: pseudo-generics and commercial practice. Aust Health Rev 2004;28:207–17.