Medicines Q&As Q&A Which medicines should be considered for brand-name prescribing in primary care?

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1 Medicines Q&As Q&A Which medicines should be considered for brandname in primary care? Prepared by UK Medicines Information (UKMi) pharmacists for NHS healthcare professionals Before using this Q&A, read the disclaimer at Date prepared: July 2013 Summary Prescribing medicines by generic rather than brand name can improve costeffectiveness and is encouraged. However, there are some circumstances in which continuity of the same brand is important for patient safety and brandname 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 are not Where there are important differences in formulation between brands of the same medicine. Where products contain multiple ingredients and brand name aids identification. Where administration devices (e.g. inhaler or selfinjection) 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 are that it is generally more costeffective than 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 in the UK has long been encouraged. A measure of generic in primary care ( potential generic savings ) in England is reported as a comparator [5]. Although generic 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 The NHS Dictionary of Medicines and Devices () and NHS Prescription Service Common Drug Reference database annotate medicines not recommended for generic [6, 7]. Prescribing software systems may also indicate medicines for which brand name is preferred. 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 can lead to the patient receiving a subtherapeutic or toxic dose. Examples include ciclosporin, lithium, CFCfree beclometasone metered dose inhalers and some antiepileptic medicines.

2 Where modified release 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 (e.g. Durogesic DTrans, Matrifen) and reservoir formulations (e.g. Tilofyl). Reservoir patches must not be cut because damage to the ratelimiting 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 aids identification. This is useful when products with multiple ingredients (e.g. pancreatin supplements, skin and scalp ) 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 prefilled 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). Answer The following table lists medicines that might be considered for brandname. This table has been compiled using a number of sources. for individual medicines are included where appropriate. Chapter Antacids containing simeticone Compound alginates and proprietary indigestion To aid identification. Products contain To aid identification. Products contain Mesalazine oral The delivery characteristics of oral mesalazine may vary and should not be considered Bulk forming laxatives To aid identification. Products contain Macrogols (polyethylene glycols) To aid identification. Products contain Compound haemorrhoid To aid identification. Products contain Pancreatin supplements To aid identification. Products contain Chapter Diltiazem modified release (MR) MR have different release characteristics and are not

3 2.6.2 Nifedipine modified release Chapter 3 MR have different release characteristics and are not Formoterol dry powder inhalers Patient familiarity with one brand is between Salbutamol dry powder inhalers Patient familiarity with one brand is between Theophylline modified release Aminophylline modified release 3.2 Beclometasone dipropionate CFCfree pressurised metered dose inhalers MR have different release characteristics and are not Theophylline has a narrow therapeutic index. MR have different release characteristics and are not Aminophyline has a narrow therapeutic index. Qvar and Clenil Modulite are not Qvar has extrafine particles and is approximately twice as potent as Clenil Modulite and CFCcontaining beclometasone inhalers. The MHRA has advised that CFCfree beclometasone inhalers should be prescribed by brand name. This applies also to combination products. MHRA [8] 3.2 Beclometasone dry powder inhalers Patient familiarity with one brand is between. 3.2 Beclometasone and formoterol CFCfree metered dose inhalers See beclometasone CFCfree metered dose inhalers, above. MHRA [8] 3.2 Budesonide dry powder inhalers Patient familiarity with one brand is between Adrenaline (epinephrine) prefilled syringes Chapter 4 Patient familiarity with one brand is between Lithium Preparations vary widely in bioavailability. Changing the preparation requires the same precautions as initiation of treatment. Lithium has a narrow therapeutic index. 4.4 Methylphenidate modified release MR contain different proportions of immediaterelease and modifiedrelease methylphenidate.

4 4.7.2 Morphine oral modified release MR have different release characteristics; Patient familiarity with one PCF4 [9] Fentanyl patches Patches are available as matrix and reservoir formulations; Patient familiarity with one Reservoir patches (e.g. Tilofyl) must not be cut because damage to the ratelimiting 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 (e.g. Durogesic DTrans, Matrifen) Botulinum toxin type A Preparations are not interchangeable due to differences in potency Antiepileptic medicines Loss of seizure control has been reported in patients after switching brands of antiepileptic medicines. Continuity of the same brand, or the same generic preparation is recommended 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.) Carbamazepine Different may vary in bioavailability. Carbamazepine has a narrow therapeutic index Lamotrigine Generic and branded products are considered bioequivalent Levetiracetam Generic and branded products are considered bioequivalent Phenytoin On the basis of single dose tests there are no clinically relevant differences in bioavailability between available phenytoin sodium tablets and capsules but there may be a pharmacokinetic basis for maintaining the same brand of phenytoin in some patients. Phenytoin has a narrow therapeutic index. PCF4 [9] NICE [10] Epilepsy Action [11]

5 4.8.1 Topiramate Generic and branded products are considered bioequivalent Apomorphine prefilled syringe Patient familiarity with one brand is between Botulinum toxin type A Preparations are not interchangeable due to differences in potency. Chapter Insulins Patient familiarity with the same brand is important; training is required in the use of specific devices for selfinjection Hormone replacement therapy oral Different brands of the same formulation are available. Patient familiarity with one Estradiol transdermal patches Different brands of the same formulation are available. Patient familiarity with one Somatropin injection cartridges Patient familiarity with the same brand is important and training is required in the use of specific devices for selfinjection. Some somatropin are licensed as biosimilar medicines. Chapter Combined oral contraceptives Different brands of the same formulation are available. Patient familiarity with one Progestogen only oral contraceptives Different brands of the same formulation are available. Patient familiarity with one Alprostadil injection Patient familiarity with one brand is between. Chapter 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 Mycophenolate Generic and branded 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 are not Eur Soc Org Trans [12] Eur Soc Org Trans [12] PJ [13]

6 8.2.2 Ciclosporin Preparations are not interchangeable and should be prescribed by brandname 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. Eur Soc Org Trans [12] MHRA [14] 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. MHRA [15] Interferon prefilled disposable injection devices Peginterferon prefilled disposable injection devices Patient familiarity with one brand is between. Chapter Erythropoietins Patient familiarity with the same brand is important and training is required in the use of specific devices for selfinjection. Some epoetin are licensed as biosimilar medicines Granulocytecolony stimulating factors Patient familiarity with the same brand is important and training is required in the use of specific devices for selfinjection. Filgrastim have been approved as biosimilar Oral rehydration salts To aid identification. Products contain Calcium salts To aid identification. Products contain Chapter Saliva replacement products To aid identification. Products contain Chapter Preparations for skin and scalp conditions containing multiple ingredients To aid identification. Products contain Also, potency of topical corticosteroid is a result of the formulation as well as the corticosteroid. Chapter Human papillomavirus vaccine Cervarix (bivalent vaccine) and Gardasil (quadravalent vaccine) are not considered

7 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 Accessed at on 4/9/ Irish Medicines Board. Generic and interchangeable medicines. Accessed at on 4/9/ Joint Formulary Committee. British National Formulary (online) London: BMJ Group and Pharmaceutical Press. Accessed via on 4/9/ NHS Choices. Medicines information brand names and generics. Reviewed 24/10/2012. Accessed at on 3/9/ NHS Business Services Authority. Prescribing comparators. Accessed at on 4/9/ NHS Business Services Authority. NHS Dictionary of Medicines and Devices () Editorial Policy. Release 2.3. August Accessed via on 4/9/ Information Services, NHS Business Services Authority Prescription Services. Items indicated as not being suitable for generic, 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 on 4/9/ Twycross R, Wilcock A (eds). Palliative Care Formulary. 4th Edition. Nottingham: Palliativedrugs.com Ltd : 2011 pp362, 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 Accessed at on 4/9/ Epilepsy Action. Getting the same version of your epilepsy medicine every time. January Accessed at on 4/9/ European Society for Organ Transplantation Advisory Committee. Generic substitution of immunosuppressive drugs. Transpl Int 2011; 24 (12): Accessed at on 4/9/ Tynan S and Jerram P. Generic or branded mycophenolate what strategy should the NHS adopt? Pharm J 2010; 285 (7630): 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 on 4/9/ 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 on 4/9/2013.

8 Quality Assurance Prepared by Karoline Brennan, North West Medicines Information Centre Date Prepared February 2009 (partial revision May 2011) Update prepared September 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 Search strategy Inhouse enquiries [Search terms: generic, therapeutic equivalency ] online [Search terms: brand, bioavailability, interchangeable ] NICE Evidence Search [Search terms: generic, individual drug names] NHS Choices [generic medicines] Irish Medicines Board 65 paper copy NHS Business Services Authority General internet searches [Search terms included nhs generic medicines, QIPP generic, NHS England generic medicines]