Prescription générique

Synonym: non-proprietary prescribing

What is generic prescribing?¹

Generic prescribing uses the recommended International Non-proprietary Name. Prescribing medicines by generic name is generally preferred but there are some circumstances when brand-name prescribing is warranted. Brand prescribing uses the branded (proprietary) or branded generic name. Increasing the level of generic prescribing in the UK has long been encouraged.

• Reduces risk: each drug has only one generic name, but may have many brand names. Generic prescribing can reduce prescribing and dispensing errors.

• Enables quicker medicine supply: if a medicine is prescribed by generic name, the pharmacist may dispense any suitable generic or branded product, which can reduce delays in supplying medicines to the patient. In primary care, if a medicine is prescribed by brand name, the pharmacist may dispense only the specified brand, unless a Serious Shortage Protocol (SSP) is in place.

• Offers value for money: it is usually more cost-effective to prescribe generically as the pharmacy is reimbursed at a set price, listed in the Drug Tariff.

There are situations where prescribing by brand is necessary. Circumstances include:

• Where bioavailability differs between brands, particularly if the medicine has a narrow therapeutic index. Lack of clarity over which preparation is required can lead to the patient receiving a sub-therapeutic or toxic dose. Examples include: ciclosporin, lithium, CFC-free beclometasone metered dose inhalers, carbamazepine for epilepsy

• Where modified release (MR) preparations are not interchangeable, eg, methylphenidate.

• Specific device directions: when administration devices have different instructions for use and patients require training to use them. Examples include: adrenaline auto-injectors, dry powder inhalers, insulin injection devices.

• Biologics and biosimilars: the MHRA advises that biologic medicines, including biosimilar medicines, should be prescribed by brand name. There is more information about biologics and biosimilars at Understanding biological and biosimilar medicines. Examples include: insulins, enoxaparin, erythropoietin.

Biological medicines are medicines that are made by or derived from a biological source using biotechnology processes, such as recombinant DNA technology. A biosimilar medicine is a biological medicine that is highly similar and clinically equivalent (in terms of quality, safety, and efficacy) to an existing biological medicine that has already been authorised.

When should prescribing by brand name also be considered?

• Ensuring supply of a consistent product can be helpful in some other circumstances, depending on the products and the patient.

• Multi-ingredient preparations: products contain more than one ingredient. Brand-name prescribing aids identification of the correct product. Examples include: pancreatin supplements, skin or scalp preparations

• Licence variations: where branded and generic preparations have different licensed indications.

• Generic preparations are licensed on the basis of bioequivalence with the branded product and it can be argued that brand-name prescribing is not necessary. However, The MHRA advise a medicine should not be used ‘off-label’ for an unlicensed indication when a licensed alternative exists. Buprenorphine 400mcg sublingual tablets is an example where licensed indication differs between brands

• Patient factors: for some patients, differences in product name, presentation, appearance or taste may lead to anxiety, confusion, dosing errors and reduced adherence.

Which drugs should always be prescribed by brand name?

Prescribe certain medicines by brand to ensure supply of the same product. Examples include (this is not an exhaustive list):

• Allergy and immunology: adrenaline.

• Anaesthesia and pain: opioid patches, opioids MR.

• Cardiovascular: metolazone, diltiazem MR, nifedipine MR, enoxaparin.

• Endocrinology: insulins

• Gastrointestinal: mesalazine.

• Mental health: lithium, methylphenidate MR.

• Neurology: antiseizure (antiepileptic) medications.

• Organ transplantation: ciclosporin, tacrolimus.

• Respiratory: inhalers, tiotropium.

This can be achieved by:

• Education of doctors and pharmacists.

• Education and information for patients.

• Good quality control and regulation to maintain therapeutic equivalence*.

• Incentives to encourage generic prescribing.

• Careful selection of brand names.