Advice for patients

Generic drugs versus branded drugs

The vast majority of drugs dispensed in pharmacies are generic drugs. In some circumstances, patient request branded products to be dispensed or prescriber decides to write a prescription for branded rather than a generic product. Does it really matter which drugs are used by patients? What is the difference between branded and generic drug? Can patient request branded product to be dispensed on ‘generic prescription’?

Difference between generic drugs and branded drugs

Branded drugs are given a name by a company that makes a drug. Branded name always differs from the International Nonproprietary Name (INN), the generic name which is usually the name of the active ingredient. Branded medication may include drugs which were developed originally for the first time to treat a specific condition. For example, Lipitor (produced by Pfizer) was the first brand of atorvastatin licensed for the treatment of high cholesterol. After the expiry of patent protection in 2016, other manufacturers began to produce generic versions of atorvastatin which became available at a much lower cost.

A company producing a generic drug may decide to name it, hence making it a branded generic product.

Branded drugs: patent protection

When a drug is developed a company that makes it has exclusive rights to produce it. This is secured with patent protection which normally lasts 20 years and is applied at early stages of drug development. It takes around 10 years to take a drug from the discovery phase to the licensing phase where drugs are available for patients to use.

Once a patent expires, other manufacturers can produce generic versions of the same medication once they pass all necessary legal requirements including bioequivalent studies.

In most cases, branded drugs are more expensive, at least during the duration of the patent as a company that makes it need to recuperate the high cost of drug development.

Generic drugs contain the same active ingredient as branded drug and they are used for the treatment of the same disease using the same dosage regiment.

Are branded drugs better than generic drugs?

Licensing and production of drugs are strictly controlled. The generic manufacturer needs to demonstrate that new generic drug is equivalent to branded medicine in terms of efficacy, safety and that it is therapeutically equivalent (bioequivalent) (EMA, 2011). This does not mean that the generic medications need to look the same, have the same tablet shape or use the same excipients in the production of the drugs. In fact, all of these normally differ between drugs.

Bioequivalent requirements between branded and generic drugs

Bioequivalent studies are conducted in healthy individuals and must be performed before any drug is given a license. Food and Drug Administration (FDA) and European Medicines Agency (EMA) look at two parameters to determine if two drugs are bioequivalent:

  • Area under the curve (AUC)
  • The highest concentration of drug in the body (CMax)

AUC reflects plasma concentration (amount of the drug) over time after the drugs is taken by the patient. It is measured by taking blood samples of the patient at specific times.  This is a useful parameter as it gives an idea of how much drug gets into the body and how fast is cleared from the body.

Cmax is self-explanatory as it reflects maximum concentration of drug in the body after a drug is taken.

AUC and Cmax for new generic drug need to be within 80-125% of a reference drug (branded drug) with 90% of confidence interval (we are 90% certain/confident that our range of results contain the true mean). In other words, 90% of the time our results for AUC and Cmax need to fall within 80%-125%. License is not given to generic drugs which fail to meet those criteria.

The range of 80%-125% has nothing to do with how much of active ingredient generic medication contains as compared to a branded product.

One of the best examples of systemic review and meta-analysis on the use of branded versus generic drugs is Clinical Equivalence of Generic Brand-name Drugs Used in Cardiovascular Disease. This research paper looked at the use of branded and bioequivalent generic drugs from 1984 to 2008 in the treatment of cardiovascular conditions. This  covered 47 studies of which 81% included randomised controlled trials. The main conclusion for all studies was that use of branded and generic drugs resulted in similar clinical outcomes (Kesselheim et al, 2008).

Can patient request a branded product to be dispensed?

Most of the prescriptions are written generically. Patients may request to have a branded product supplied; however, it is unlikely that the pharmacy will fulfill this request. This is mainly due to the price difference between generic and branded drugs. When a prescription is written generically, pharmacies receive reimbursement (payment) from NHS for the cost of generic drug and if a branded product is supplied a pharmacy occurs a loss on supply. The difference in cost between generic and branded drugs can be significant. Occasionally pharmacies have different deals with manufacturers of branded products and by default branded drug is supplied.

The table below list examples of few drugs to show the price difference between branded and generic drugs and lists reimbursement from NHS for the supply of generic medication (AHH, 2019). Some of the listed drugs include the most prescribed drugs in the UK.

Drug name

Price of branded drug Price of generic drug NHS reimbursement (generic)

Sildenafil 100mg tablets (4)

£23.50 (Viagra) £0.74 £0.80

Amlodipine 5mg (28)

£10.50 (Istin) £0.65

£0.71

Atorvastatin 20mg (28)

£26.64 (Lipitor) £0.77

£0.81

Ramipril 5mg tablets (28)

£9.02 (Tritace) £3.75

£4.63

Sertraline 50mg tabs (28)

£17.82 (Lustral) £1.49

£0.82

Omeprazole 20mg caps(28)

£15.87 (Losec) £0.78

£0.83

Are all drugs issued generically?

Certain medications should only be prescribed by its brand names in order to maintain the same supply and to minimise any risk associated with brand switching. Some common drugs prescribed by brands include anti-epileptic drugs including phenytoin, carbamazepine, phenobarbital, and primidone.

Other examples of a group of medicines prescribed by the brand include drugs with a narrow therapeutic index (window between therapeutic and toxic level is small) and modified release preparations.

In conclusion, generic drugs bring several advantages to patients and NHS. Lower cost for generic drugs drives prescribing. Generic drugs contribute to a better availability and faster supply to patients. Strict legal requirements (bioequivalent studies) and licensing process ensure that generic drugs have almost the same therapeutic actions as branded drugs.

References:

AAH (2019). Full branch stock list code (February 2019). Available at: http://www.w8dm.co.uk/KEP/AAH/FILES/HTML/201902/BRANCH_STOCK_CODE_FEB19.html

Accessed on 29/04/19

EMA (2011). Interchangeability of generics. Available at: https://www.ema.europa.eu/en/documents/presentation/presentation-interchangeability-generics_en.pdf Accessed on 29/04/19

Kesselheim AS, Misono AS, Lee JL, Stedman MR, Brookhart MA, Choudhry NK, Shrank WH (2008). Clinical equivalence of generic and brand-name drugs used in cardiovascular disease: a systematic review and meta-analysis. Available at: https://www.ncbi.nlm.nih.gov/pubmed/19050195 Accessed on 29/04/19

I am a community pharmacist working in UK. I blog about drugs, health and pharmacy.

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