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Medicines Q&As Q&A 247.3 Which medicines should be considered for brand-name prescribing in primary care? Prepared by UK Medicines Information (UKMi) pharmacists for NHS healthcare professionals Before using this Q&A, read the disclaimer at www.ukmi.nhs.uk/activities/medicinesQAs/default.asp Date prepared: July 2013 (partial update December 2013) Summary Prescribing medicines by generic rather than brand name can improve cost-effectiveness and is encouraged. However, there are some circumstances in which continuity of the same brand is important for patient safety and brand-name prescribing preferred. These include: Where there is a difference in bioavailability between brands of the same medicine, particularly if the medicine has a narrow therapeutic index. Where modified release preparations are not interchangeable. Where products contain multiple ingredients and brand name prescribing aids identification. Where there are important differences in formulation between brands of the same medicine. Where administration devices (e.g. inhaler or self-injection) have different instructions for use and patient familiarity with one product is important. Where the product is a biological rather than chemical entity. Background Medicines may be prescribed by ‘brand’ (proprietary) or ‘generic’ (recommended International Nonproprietary Name, rINN) name. In primary care, if a medicine is prescribed by brand name, the pharmacist may dispense only the specified brand and is reimbursed for doing so. If a medicine is prescribed by generic name, the pharmacist may dispense any suitable generic or branded product and is reimbursed at a set price, listed in the Drug Tariff. Proposals for ‘generic substitution’ whereby community pharmacists would be allowed to supply a generic preparation even if a branded product were prescribed have been rejected in England [1]. Legislation has recently been passed allowing generic substitution in Ireland for medicines on an ‘interchangeable list’ maintained by the Irish Medicines Board [2]. Advantages of generic prescribing are that it is generally more cost-effective than prescribing by brand name and, because it allows any suitable product to be dispensed, can reduce delays in supplying medicines to the patient [3, 4]. Increasing the level of generic prescribing in the UK has long been encouraged. A measure of generic prescribing in primary care (‘potential generic savings’) in England is reported as a prescribing comparator [5]. Although generic prescribing is encouraged there are some circumstances in which it is preferable to prescribe by brand name. Broadly these circumstances are where continuity of the same brand is important due to differences in bioavailability, where patient training differs between products and to aid identification where products have multiple ingredients. The NHS Dictionary of Medicines and Devices (dm+d) and NHS Prescription Service Common Drug Reference database annotate medicines not recommended for generic prescribing [6, 7]. Prescribing software systems may also indicate medicines for which brand name prescribing is preferred. Specific circumstances are described below: Where there is a difference in bioavailability between brands of the same medicine, particularly if the medicine has a narrow therapeutic index. In these circumstances, lack of clarity over which preparation is intended when prescribing can lead to the patient receiving a sub-therapeutic or toxic dose. Examples include ciclosporin, lithium, CFC-free beclometasone metered dose inhalers and some antiepileptic medicines. Available through NICE Evidence Search at www.evidence.nhs.uk Where modified release preparations are not interchangeable, particularly if the medicine has a narrow therapeutic index. This avoids confusion between formulations with different release characteristics. Examples include aminophylline, diltiazem and morphine. Where there are important differences in formulation between brands of the same medicine. For example, fentanyl patches are available as matrix formulations and reservoir formulations. Reservoir patches must not be cut because damage to the rate-limiting membrane can lead to a rapid release of fentanyl resulting in overdose. If the prescriber intends the patch to be cut (although this is unlicensed and not recommended by the MHRA) then the prescription must specify a brand of matrix formulation patch. Where products contain more than one ingredient and brand name prescribing aids identification. This is useful when prescribing products with multiple ingredients (e.g. pancreatin supplements, skin and scalp preparations) and to differentiate between similar products where patient familiarity with a brand is important (e.g. hormone replacement therapy and oral contraceptives). Where administration devices have different instructions for use and patient familiarity with one product is important. For example salbutamol dry powder inhalers and adrenaline pre-filled syringes. Where the product is a biological rather than chemical entity. Such agents are licensed as ‘biosimilar’ medicines. Examples include erythropoietin and somatropin (growth hormone) preparations. Answer The following table lists medicines that might be considered for brand-name prescribing. This table has been compiled using a number of sources. Specific references for individual medicines are included where appropriate. BNF Drug or drug class Reason for considering brand-name prescribing Specific references Chapter 1 1.1.1 Antacids preparations containing simeticone To aid identification. Products contain multiple ingredients. BNF 1.1.2 Compound alginates and proprietary indigestion preparations To aid identification. Products contain multiple ingredients. BNF 1.5.1 Mesalazine oral preparations The delivery characteristics of oral mesalazine preparations may vary and should not be considered interchangeable. BNF 1.6.1 Bulk forming laxatives To aid identification. Products contain multiple ingredients. - 1.6.4 Macrogols (polyethylene glycols) To aid identification. Products contain multiple ingredients. - 1.7.2 Compound haemorrhoid preparations To aid identification. Products contain multiple ingredients. - 1.9.4 Pancreatin supplements To aid identification. Products contain multiple ingredients. - Chapter 2 2.6.2 Diltiazem modified release (MR) preparations MR preparations have different release characteristics and are not interchangeable. Available through NICE Evidence Search at www.evidence.nhs.uk BNF dm+d BNF 2.6.2 Drug or drug class Nifedipine modified release preparations Reason for considering brand-name prescribing Specific references MR preparations have different release characteristics and are not interchangeable. BNF dm+d Chapter 3 3.1.1 Formoterol dry powder inhalers Patient familiarity with one brand is important; instructions for use vary between preparations. dm+d 3.1.1 Salbutamol dry powder inhalers Patient familiarity with one brand is important; instructions for use vary between preparations. dm+d 3.1.3 Theophylline modified release preparations MR preparations have different release characteristics and are not interchangeable. Theophylline has a narrow therapeutic index. BNF 3.1.3 Aminophylline modified release preparations MR preparations have different release characteristics and are not interchangeable. Aminophyline has a narrow therapeutic index. BNF dm+d 3.2 Beclometasone dipropionate CFCfree pressurised metered dose inhalers Qvar and Clenil Modulite are not interchangeable. Qvar has extra-fine particles and is approximately twice as potent as Clenil Modulite and CFCcontaining beclometasone inhalers. The MHRA has advised that CFC-free beclometasone inhalers should be prescribed by brand name. This applies also to combination products. BNF dm+d MHRA [8] 3.2 Beclometasone dry powder inhalers Patient familiarity with one brand is important; instructions for use vary between preparations. 3.2 Beclometasone and formoterol CFC-free metered dose inhalers See beclometasone CFC-free metered dose inhalers, above. 3.2 Budesonide dry powder inhalers Patient familiarity with one brand is important; instructions for use vary between preparations. - 3.4.3 Adrenaline (epinephrine) pre-filled syringes Patient familiarity with one brand is important; instructions for use vary between preparations. BNF dm+d dm+d BNF MHRA [8] Chapter 4 4.2.3 Lithium preparations Preparations vary widely in bioavailability. Changing the preparation requires the same precautions as initiation of treatment. Lithium has a narrow therapeutic index. BNF dm+d 4.4 Methylphenidate modified release preparations MR preparations contain different proportions of immediate-release and modified-release methylphenidate. BNF dm+d Available through NICE Evidence Search at www.evidence.nhs.uk BNF Drug or drug class Reason for considering brand-name prescribing Specific references 4.7.2 Morphine oral modified release preparations MR preparations have different release characteristics; Patient familiarity with one brand is important. PCF4 [9] 4.7.2 Fentanyl patches Patches are available as matrix and reservoir formulations; Patient familiarity with one brand is important. Reservoir patches must not be cut because damage to the rate-limiting membrane can lead to a rapid release of fentanyl resulting in overdose. If the prescriber intends the patch to be cut (NB: unlicensed and not recommended by the MHRA) then the prescription must specify a brand of matrix formulation patch. PCF4 [9] 4.7.4 Botulinum toxin type A Preparations are not interchangeable due to differences in potency. BNF dm+d 4.8.1 Antiepileptic drugs The MHRA has classified antiepileptic drugs (AEDs) into three categories of risk, based primarily on their therapeutic index and physiochemical characteristics (in particular solubility and permeability across membranes) indicative of potential differences between formulations. MRHA [10,11] Category 1: Specific measures are necessary to ensure consistent supply of a particular product (which could be either a branded product or a specified manufacturer’s generic product). Category 2: NB: By default, this category includes all AEDs not listed in categories 1 or 3. The need for continued supply of a particular manufacturer’s product should be based on clinical judgement and consultation with patient and/or carer. Category 3: No specific measures are normally required and these AEDs can be prescribed generically and without specifying a specific manufacturer’s product: NICE recommends continuity of the same brand, or the same generic preparation, for patients with seizure disorders, unless the prescriber (in consultation with the patient and their family or carers) considers this not to be a concern. (For individual antiepileptic agents, see below.) Available through NICE Evidence Search at www.evidence.nhs.uk NICE [12] BNF Drug or drug class Reason for considering brand-name prescribing Specific references 4.8.1 Carbamazepine MHRA Category 1 (see ‘Antiepileptic drugs’ above). MRHA [11] 4.8.1 Ethosuxamide MHRA Category 3 (see ‘Antiepileptic drugs’ above). MRHA [11] 4.8.1 Gabapentin MHRA Category 3 (see ‘Antiepileptic drugs’ above). MRHA [11] 4.8.1 Lacosamide MHRA Category 3 (see ‘Antiepileptic drugs’ above). MRHA [11] 4.8.1 Levetiracetam MHRA Category 3 (see ‘Antiepileptic drugs’ above). MRHA [11] 4.8.1 Phenobarbital MHRA Category 1 (see ‘Antiepileptic drugs’ above). MRHA [11] 4.8.1 Phenytoin MHRA Category 1 (see ‘Antiepileptic drugs’ above). MRHA [11] 4.8.1 Pregabalin MHRA Category 3 (see ‘Antiepileptic drugs’ above). MRHA [11] 4.8.1 Primidone MHRA Category 1 (see ‘Antiepileptic drugs’ above). MRHA [11] 4.8.1 Tiagabine MHRA Category 3 (see ‘Antiepileptic drugs’ above). MRHA [11] 4.8.1 Vigabatrin MHRA Category 3 (see ‘Antiepileptic drugs’ above). MRHA [11] 4.9.1 Apomorphine pre-filled syringe Patient familiarity with one brand is important; instructions for use vary between preparations. dm+d 4.9.3 Botulinum toxin type A Preparations are not interchangeable due to differences in potency. BNF dm+d dm+d Chapter 6 6.1.1 Insulins Patient familiarity with the same brand is important; training is required in the use of specific devices for self-injection. 6.4.1 Hormone replacement therapy oral preparations Different brands of the same formulation are available. Patient familiarity with one brand is important. - 6.4.1 Estradiol transdermal patches Different brands of the same formulation are available. Patient familiarity with one brand is important. - 6.5.1 Somatropin injection cartridges Patient familiarity with the same brand is important and training is required in the use of specific devices for self-injection. Some somatropin preparations are licensed as ‘biosimilar’ medicines. BNF dm+d Different brands of the same formulation are available. Patient familiarity with one brand is important. - Chapter 7 7.3.1 Combined oral contraceptives Available through NICE Evidence Search at www.evidence.nhs.uk BNF Drug or drug class Reason for considering brand-name prescribing 7.3.2 Progestogen only oral contraceptives Different brands of the same formulation are available. Patient familiarity with one brand is important. 7.4.5 Alprostadil injection Patient familiarity with one brand is important; instructions for use vary between preparations. Specific references - dm+d Chapter 8 8.2.1 Azathioprine Different formulations may vary in bioavailability; to avoid reduced effect or excessive side effects, it is important not to change formulation except on the advice of a transplant specialist. BNF Eur Soc Org Trans [12] 8.2.1 Mycophenolate Generic and branded preparations are considered bioequivalent but it may be prudent not to change formulation except on the advice of a transplant specialist. Mycophenolate mofetil and mycophenolic acid preparations are not interchangeable. BNF Eur Soc Org Trans [12] PJ [13] 8.2.2 Ciclosporin Preparations are not interchangeable and should be prescribed by brand-name to avoid inadvertent switching. It is important not to change formulation except on the advice of a transplant specialist. Ciclosporin has a narrow therapeutic index. BNF dm+d Eur Soc Org Trans [12] MHRA [14] 8.2.2 Tacrolimus Preparations are not interchangeable; care should be taken to ensure the correct preparation is prescribed and dispensed. It is important not to change formulation except on the advice of a transplant specialist. Tacrolimus has a narrow therapeutic index. BNF dm+d MHRA [15] 8.2.4 Interferon pre-filled disposable injection devices Patient familiarity with one brand is important; instructions for use vary between preparations. dm+d Peginterferon pre-filled disposable injection devices Chapter 9 9.1.3 Erythropoietins Patient familiarity with the same brand is important and training is required in the use of specific devices for self-injection. Some epoetin preparations are licensed as ‘biosimilar’ medicines. BNF dm+d 9.1.6 Granulocyte-colony stimulating factors Patient familiarity with the same brand is important and training is required in the use of specific devices for self-injection. Filgrastim preparations have been approved as ‘biosimilar’. dm+d BNF Available through NICE Evidence Search at www.evidence.nhs.uk BNF Drug or drug class Reason for considering brand-name prescribing Specific references 9.2.1 Oral rehydration salts To aid identification. Products contain multiple ingredients. - 9.5.1 Calcium salts To aid identification. Products contain multiple ingredients. - To aid identification. Products contain multiple ingredients. - To aid identification. Products contain multiple ingredients. Also, potency of topical corticosteroid preparations is a result of the formulation as well as the corticosteroid. - Chapter 12 12.3.5 Saliva replacement products Chapter 13 13.113.10 Preparations for skin and scalp conditions containing multiple ingredients Chapter 14 14.4 Human papillomavirus vaccine Cervarix (bivalent vaccine) and Gardasil (quadravalent vaccine) are not considered interchangeable. BNF Limitations This list of medicines may not be comprehensive. References 1. Department of Health. Press release: No plans to implement generic substitution of medicines. 14 October 2010. Accessed at http://webarchive.nationalarchives.gov.uk/+/www.dh.gov.uk/en/MediaCentre/Pressreleases/DH_1 20502 on 4/9/2013. 2. Irish Medicines Board. Generic and interchangeable medicines. Accessed at www.imb.ie/EN/Human-Medicines/Generic-and-Interchangeable-Medicines.aspx on 4/9/2013. 3. Joint Formulary Committee. British National Formulary (online) London: BMJ Group and Pharmaceutical Press. Accessed via www.medicinescomplete.com on 4/9/2013. 4. NHS Choices. Medicines information – brand names and generics. Reviewed 24/10/2012. Accessed at www.nhs.uk/Conditions/Medicinesinfo/Pages/Brandnamesandgenerics.aspx on 3/9/2013. 5. NHS Business Services Authority. Prescribing comparators. Accessed at www.nhsbsa.nhs.uk/PrescriptionServices/3634.aspx on 4/9/2013. 6. NHS Business Services Authority. NHS Dictionary of Medicines and Devices (dm+d) Editorial Policy. Release 2.3. August 2013. Accessed via http://195.59.176.218/dmd_download.htm on 4/9/2013. 7. Information Services, NHS Business Services Authority Prescription Services. Items indicated as not being suitable for generic prescribing, from the NHS Prescription Service Common Drug Reference database. Personal communication on 2/7/2013 (data produced 25/6/2013). 8. Medicines and Healthcare products Regulatory Agency. Inhaled products that contain corticosteroids. Drug Safety Update 2008; 12(1):8. Accessed at www.mhra.gov.uk/Safetyinformation/DrugSafetyUpdate/CON085179 on 4/9/2013. 9. Twycross R, Wilcock A (eds). Palliative Care Formulary. 4th Edition. Nottingham: Palliativedrugs.com Ltd: 2011 pp362, 392. Available through NICE Evidence Search at www.evidence.nhs.uk 10. Medicines and Healthcare products Regulatory Agency. Antiepileptic drugs: new advice on switching between different manufacturers’ products for a particular drug. Drug Safety Update November 2013; 7 (4): A1. Accessed at: www.mhra.gov.uk/home/groups/dsu/documents/publication/con336729.pdf on 3/12/2013. 11. Medicines and Healthcare products Regulatory Agency. Formulation switching of antiepileptic drugs: A report on the recommendations of the Commission on Human Medicines from July 2013. Accessed at http://www.mhra.gov.uk/home/groups/commsic/documents/websiteresources/con341226.pdf on 3/12/2013. 12. National Institute for Health and Clinical Excellence. Clinical guideline 137: The epilepsies – the diagnosis and management of the epilepsies in adults and children in primary and secondary care. January 2012. Accessed at www.nice.org.uk/nicemedia/live/13635/57779/57779.pdf on 4/9/2013. 13. European Society for Organ Transplantation Advisory Committee. Generic substitution of immunosuppressive drugs. Transpl Int 2011; 24 (12): 1135-1141. Accessed at http://onlinelibrary.wiley.com/doi/10.1111/j.1432-2277.2011.01378.x/pdf on 4/9/2013. 14. Tynan S and Jerram P. Generic or branded mycophenolate – what strategy should the NHS adopt? Pharm J 2010; 285 (7630): 659-660. 15. Medicines and Healthcare products Regulatory Agency. Ciclosporin must be prescribed and dispensed by brand name. Drug Safety Update Dec 2009; 3 (5): 2. Accessed at www.mhra.gov.uk/Safetyinformation/DrugSafetyUpdate/CON087726 on 4/9/2013 16. Medicines and Healthcare products Regulatory Agency. Oral tacrolimus products: prescribe and dispense by brand name only, to minimise the risk of inadvertent switching between products, which has been associated with reports of toxicity and graft rejection. Drug Safety Update 2012; 5 (11): A1. Accessed at www.mhra.gov.uk/Safetyinformation/DrugSafetyUpdate/CON155756 on 4/9/2013. Quality Assurance Prepared by Karoline Brennan, North West Medicines Information Centre Date Prepared February 2009 (partial revision May 2011) Update prepared September 2013 (partial update December 2013) Checked by Simone Henderson, North West Medicines Information Centre Christine Proudlove, North West Medicines Information Centre Date of check February 2009 (partial revision May 2011) Update checked September 2013 (partial update December 2013) Search strategy In-house enquiries [Search terms: “generic prescribing”, “therapeutic equivalency”] BNF online [Search terms: “brand”, “bioavailability”, “interchangeable”] NICE Evidence Search [Search terms: generic prescribing, individual drug names] NHS Choices [generic medicines] Irish Medicines Board BNF 65 paper copy NHS Business Services Authority General internet searches [Search terms included nhs generic medicines, QIPP generic prescribing, NHS England generic medicines] Available through NICE Evidence Search at www.evidence.nhs.uk