Generic medicines: Greek physicians' perceptions and prescribing practices

Background and objective:  The penetration of generic drugs in the Greek pharmaceutical market is placed among the weakest in the EU. The Greek regulatory framework does not systematically support the development of this subsector and physicians are not provided with incentives for prescribing generics. The aim of this study was to investigate the prescribing profile of physicians in Greece with a focus on the factors that influence their decision on generics prescribing.
Methods:  A structured questionnaire was sent by mail to a random national sample of 1463 physicians, stratified by sex, specialty and geographical region.
Results and discussion:  The response rate was 82·3%. Greek physicians have a positive view on generics but they prefer to prescribe the original products. According to our analysis, physician's age and their opinion on generics' efficacy and effectiveness are identified as important determinants of their prescribing decision. The primary reason that could make them change their prescribing habits is the appearance of side-effects. Patients' insurance coverage and income, as well as the drug cost are also referred as factors that influence their prescribing decision. Despite the fact that they do not usually prescribe generics in their clinical practice, they are willing to substitute an original drug by a generic product.
Conclusions:  Our findings suggest that Greek physicians could be persuaded to prescribe generic medicines, if a generic promotion policy was introduced in the country. To develop such a policy, a set of supply side and demand-side measures should be implemented along with provision of information on generics to physicians during their education and clinical practice.     

The bioequivalence and therapeutic efficacy of generic versus brand-name psychoactive drugs

BACKGROUND: For the purposes of drug approval, the interchangeability of a generic drug and the corresponding brand-name drug is based on the criterion of "essential similarity," which requires that the generic drug have the same amount and type of active principle, the same route of administration, and the same therapeutic effectiveness as the original drug, as demonstrated by a bioequivalence study. However, bioequivalence and therapeutic effectiveness are not necessarily the same. OBJECTIVE: This review summarizes available data comparing the bioequivalence and therapeutic efficacy of brand-name psychoactive drugs with those of the corresponding generic products. METHODS: Relevant information was identified through searches of MEDLINE, Current Contents/Clinical Medicine, and EMBASE for English-language articles and English abstracts of articles in other languages published between 1975 and the present. The search terms used were generic drug, branded drug, safety, toxicity, adverse events, clinical efficacy, bioequivalence, bioavailability, psychoactive drugs, and excipients. RESULTS: Few publications compared the bioequivalence and efficacy of brand-name and generic psychoactive drugs. Those that were identified revealed differences in the efficacy and tolerability of brand-name and generic psychoactive drugs that had not been noted in the original bioequivalence studies. Specifically, l study found that plasma levels of phenytoin were 31% lower after a switch from a brand-name to a generic product. Several controlled studies of carbamazepine showed a recurrence of convulsions after the shift to a generic formulation. After a sudden recurrence of seizures when generic valproic acid was substituted for the brand-name product, an investigation by the US Food and Drug Administration found a difference in bioavailability between the 2 formulations. Statistically significant differences in pharmacokinetic variables have been reported in favor of brand-name versus generic diazepam (P < 0.001). Finally, a case report involving paroxetine mesylate cast doubt on the tolerability and efficacy of the generic formulation. CONCLUSION: The essential-similarity requirement should be extended to include more rigorous analyses of tolerability and efficacy in actual patients as well as in healthy subjects.     

Generic substitution of antihypertensive drugs: does it affect adherence?

BACKGROUND: Generic substitution is an important opportunity to reduce the costs of pharmaceutical care. However, pharmacists and physicians often find that patients and brand-name manufacturers have doubt about the equivalence of the substituted drug. This may be reflected by decreased adherence to therapy. OBJECTIVE: To assess the association between generic substitution and nonadherence to antihypertensive drugs. METHODS: We conducted a matched cohort study between January 1, 1999, and December 31, 2002. Data were obtained from PHARMO, a record linkage system containing drug-dispensing records from community pharmacies and linked hospital discharge records of approximately 950,000 people in The Netherlands. Residents of 30 medium-sized cities who initiated antihypertensive drug therapy were potential subjects. Refill adherence with antihypertensive drugs after substitution was determined; those with refill adherence below 80% were considered nonadherent. RESULTS: Four hundred sixty-three patients with a substitution in therapy and 565 controls, matched on age, gender, therapy start date, duration of use, and generic product code, were identified. Of the patients who switched from brand-name to generic formulations ("substituted"), 13.6% were nonadherent, and of the non-substituted patients (those who did not switch to generic), 18.7% were nonadherent (OR 0.68; 95% CI 0.48 to 0.96). The association was absent in males. None of the patients discontinued the medication. No differences in hospitalizations for cardiovascular disease in the 6 months after the substitution were observed. CONCLUSIONS: Generic substitution of antihypertensive drugs does not lead to lower adherence or more discontinuation and cardiovascular disease-related hospitalizations compared with brand-name therapy. When a less-expensive antihypertensive generic equivalent becomes available, generic substitution should be considered to achieve economic benefits.     

Bioequivalence and other unresolved issues in generic drug substitution

BACKGROUND: Substitution of generic drugs for brand-name products is highly controversial and often is met with suspicion by health care providers and patients. Historically, the debate has focused on the issue of bioequivalence, and clinical practice has identified a number of drug classes for which generic substitution should be approached with caution. Current bioequivalence requirements are based on a measure of average bioequivalence; however, there are fears that use of this measure may be inappropriate in the case of a drug with a narrow or wide therapeutic range or high intrasubject or intersubject variability. Under these circumstances, measures of individual and population bioequivalence are proposed to be more accurate than measures of average bioequivalence. OBJECTIVE: This paper addresses issues of bioequivalence and other concerns with generic drug substitution. METHODS: I conducted a MEDLINE search of the English-language literature containing the key terms generic, multisource, quality, and brand and published between 1973 and 2003. The names of branded pharmaceuticals whose patents had recently expired (eg, Ventolin HFA, Adalat, Capoten, Tagamet HB 200, and Valium) also were used to search for articles on generic substitution. Reference lists of relevant articles also were searched. Bioequivalence issues are presented together with more general concerns over generic drug substitution, such as consumer perception of risk, differences in product and packaging appearance, and differences in excipients. RESULTS: The literature reviewed act to highlight a number of different drug categories and patient subpopulations for which generic substitution can still prove to be problematic. CONCLUSION: I recommend that health care providers continue to exercise caution in the consideration of generic drug substitution under certain circumstances.     

How practitioners view generic drugs: an opinion study from general practitioners in Maine-et-Loire (France)

INTRODUCTION: Generic drugs are copies of original drugs, hence their low cost. In France, expansion of the use of generic drugs is not significant and the support of practitioners is essential in increasing this. AIM: The purpose of this study was to survey the opinion and practical experience of physicians regarding generic drugs, in order to develop a proposal for the safer use of these drugs. METHODS: A form was sent to the 1235 general and specialist practitioners in the Maine-et-Loire "département" with assistance from the regional health insurance, in March 2002. The main topics studied were prescribing practices, risks associated with generic drugs and pharmacist substitutions. The chi2 test and Fisher's exact test were used in the data analysis. RESULTS: Four hundred and twenty-nine forms were returned (34.7%). Only 55% of practitioners considered generic drugs to be as safe and effective as original drugs. Fifty-nine percent prescribe generics rarely or never. The prescribing depends on many factors, linked to the practitioner, the patient or the drug. Many practitioners reported adverse events with generic medicines. With regard to the switch by the pharmacist, it was reported that 45% of prescribers would refuse it in some instances. Among the proposals, cooperation between practitioners and pharmacists in the choice of the generic drugs was approved by 57% of physicians. DISCUSSION: The main perception is that the vastness of the generic world and the fear of adverse events are somewhat bewildering for both patients and health professionals. Among the proposals made by practitioners, a decrease in the number of generics for a same molecule and the institution of a standard price are widely approved. CONCLUSION: Practitioners do not refuse to use generic drugs but are very concerned about the risks of adverse effects for their patients. They regard it as important that a patient receiving chronic treatment be given the same generic drug each time.     

Influence of socioeconomic status on drug selection for the elderly in Canada

OBJECTIVE: To examine the association between socioeconomic status, as indicated by neighborhood median income levels, and physician drug selection between older, less expensive generic drugs and newer, more expensive brand-name drugs for elderly patients initiating drug therapy in a universal healthcare system. METHODS: We conducted a population-based, retrospective, cross-sectional study. Using healthcare administrative databases, we assessed the medication profiles of 128 314 patients from more than 1.4 million residents of Ontario > or =65 years old initiating antipsychotic, hydroxymethylglutaryl-coenzyme A reductase inhibitor (statin), or ocular beta-blocker drug therapy from January 1, 1998, through December 31, 1999. We examined the selection of older generic drugs relative to newer brand-name agents for patients in each of 5 income quintiles. RESULTS: Overall, brand-name drug prescribing modestly increased with increasing income quintile after adjusting for patient age and gender (61.2% in the lowest income quintile vs. 64.1% in the highest income quintile; p value for trend < 0.001). Significant risk ratios comparing the highest with the lowest income-quintile patients were observed for selection of newer, brand-name antipsychotics (RR 1.14; 95% CI 1.06 to 1.23), older generic statins (RR 0.86; 95% CI 0.77 to 0.95), and newer, brand-name ocular beta-blockers (RR 1.13; 95% CI 1.02 to 1.25). CONCLUSIONS: This study suggests that income-related differences in treatment selection by physicians may exist. The reasons for these differences and subsequent impact on health outcomes warrant further investigation.     

Attitudes of Slovene general practitioners towards generic drug prescribing and comparison with international studies

BACKGROUND: Over the recent years there has been a steady 7% yearly increase in prescribing costs, which accounts for 17% of the Slovene national health care budget. Substitution of branded products by generic equivalents can offer savings. General practitioners (GPs) are often concerned about the quality of generic products and possible legal liabilities associated with their use. OBJECTIVE: We wanted to examine the attitudes of GPs in Slovenia towards generic drug prescribing. METHODS: We conducted a postal survey of a random sample of 200 out of 800 GPs in Slovenia from the National Health Insurance Institute database. GPs were asked 21 questions regarding their knowledge on generic drugs, awareness of prescribing costs, prices of generic drugs relative to brand name drugs and their attitude towards use of generic drugs. RESULTS: The 117 (58.5%) replies we received represent 15% of the GP population in Slovenia. 66.1% of GPs considered rising costs of medicines to be a serious problem for the health care budget. Each week, over 50% of GPs experienced demands from patients for specific drugs and the majority of GPs usually met their patients' demands or requests from hospital consultants for branded products. 38.3% of GPs did not take price into consideration when prescribing drugs. The majority of GPs (88.9%) perceived generics to have the same effectiveness as branded drugs. One quarter of GPs would prescribe more generics if additional clinical trials were presented. 37.3% would follow advice of academic detailers and 30.3% expected the generics to be even cheaper than they were. Independent detailing was welcomed by 63.8% of GPs because of the big influence of the pharmaceutical industry on the prescribing habits. 15.5% thought that the industry had a tremendous impact on their prescribing patterns. CONCLUSIONS: Slovene GPs are aware of the cost of prescribed drugs. They are willing to accept independent academic detailing to improve their prescribing and are willing to increase generic drugs under certain conditions.     

Case reports of the reemergence of psychotic symptoms after conversion from brand-name clozapine to a generic formulation.

BACKGROUND: The use of generic drugs has resulted in considerable cost savings; however, whether all generics are truly bioequivalent to their brand-name counterparts is questionable. Although the efficacy of clozapine in the management of treatment-resistant schizophrenia has been well established, reports of relapse after conversion to a generic formulation are becoming more common. OBJECTIVE: This article presents 7 case studies of patients in a long-term residential care facility who experienced a relapse of psychotic symptoms when the pharmacy inadvertently switched their therapy from brand-name clozapine to a generic formulation. Neither patients, physicians, nor staff of the facility were aware of this switch. Possible reasons for the apparent increased risk of relapse in some patients switched to the generic formulation of clozapine are explored, with reference to US Food and Drug Administration bioequivalence standards and reports. RESULTS: All 7 patients, whose condition had been well stabilized with brand-name clozapine, experienced a rapid and profound deterioration after the switch to the generic formulation. Five patients required hospitalization. All patients responded well when brand-name clozapine was reinstated. CONCLUSION: The findings suggest that brand-name clozapine and the generic formulation may display important clinical differences, and a comparable therapeutic response may not be achievable despite adequate monitoring. Large, controlled, prospective trials are needed to clarify the potential for treatment failure with the use of generic clozapine.     

Antimicrobial prescribing patterns for respiratory diseases including tuberculosis in Russia: a possible role in drug resistance?

BACKGROUND: Inappropriate antibiotic prescribing exposes patients to the risk of side effects and encourages the development of drug resistance across antimicrobial groups used for respiratory infections including tuberculosis (TB). AIM: Determine among Russian general practitioners and specialists: (1) sources of antimicrobial prescribing information; (2) patterns of antimicrobial prescribing for common respiratory diseases and differences between primary and specialist physicians; (3) whether drug resistance in TB might be linked to over-prescribing of anti-TB drugs for respiratory conditions. METHODS: Point-prevalence cross-sectional survey involving all 28 primary care, general medicine and TB treatment institutions in Samara City, Russian Federation. In this two-stage study, a questionnaire was used to examine doctors' antimicrobial (including TB drugs) prescribing habits, sources of prescribing information, management of respiratory infections and a case scenario ('common cold'). This was followed by a case note review of actual prescribing for consecutive patients with respiratory diseases at three institutions. RESULTS: Initial questionnaires were completed by 81.3% (425/523) of physicians with 78.4% working in primary care. Most doctors used standard textbooks to guide their antimicrobial practice but 80% made extensive use of pharmaceutical company information. A minority of 1.7% would have inappropriately prescribed antibiotics for the case and 0.8-1.8% of respondents would have definitely prescribed TB drugs for non-TB conditions. Of the 495 respiratory cases, 25% of doctors prescribed an antibiotic for a simple upper respiratory tract infection and of 8 patients with a clinical diagnosis of TB, 4 received rifampicin monotherapy alone. Ciprofloxacin was widely but inappropriately used. CONCLUSION: Doctors rely on information provided by pharmaceutical companies; there was inappropriate antibiotic prescribing.     

应用Delphi法对临床护士特定情况下药物处方权的再探讨

[目的]探讨中国临床护士特定情况下的药物处方权。[方法]采用自行设计的问卷,应用Delphi法对30名护理专家和10名医疗专家进行临床护士特定情况下药物处方权的问卷咨询。[结果]第2轮专家认同率最高的特定情况:高热时开具柴胡、对乙酰氨基酚倾向于护士独立处方形式,开具地塞米松倾向于协议处方,对高热惊厥时开具水合氯醛两种处方形式接近,开具苯巴比妥倾向于协议处方;低血糖症时开具葡萄糖溶液倾向于护士独立处方形式,开具氢化可的松倾向于协议处方;延长处方中的癌症姑息治疗时开具镇痛药两种处方形式接近、开具止吐药倾向于护士独立处方形式,高血压时开具降压药倾向于协议处方。[结论]医疗专家和护理专家对给予临床护士特定情况下一定的药物处方较认可,可以给予高热、低血糖症、高血压急症等11项特定情况时具体药物的处方权。