Drug product selection: legal issues

The impact on health outcomes and healthcare utilisation of switching to generic medicines consequent to reference pricing: the case of lamotrigine in New Zealand

BACKGROUND

Many countries have implemented generic reference pricing and substitution as methods of containing pharmaceutical expenditure. However, resistance to switching between medicines is apparent, especially in the case of anti-epileptic medicines.

OBJECTIVES

This study sought to exploit a nation-wide policy intervention on generic reference pricing in New Zealand to evaluate the health outcomes of patients switching from originator to generic lamotrigine, an anti-epileptic medicine.

METHODS

A retrospective study using the national health collections and prescription records was conducted comparing patients who switched from originator brand to generic lamotrigine with patients who remained on the originator brand. Primary outcome measures included switch behaviour, changes in utilisation of healthcare services at emergency departments, hospitalisations and use of specialist services, and mortality.

RESULTS

Approximately one-quarter of all patients using the originator brand of lamotrigine switched to generic lamotrigine, half of whom made the switch within 60 days of the policy implementation. Multiple switches (three or more) between generic and brand products were evident for around 10% of switchers. Switch-back rates of 3% were apparent within 30 days post-switch. No difference in heath outcome measures was associated with switching from originator lamotrigine to a generic equivalent and hence no increased costs could be found for switchers.

CONCLUSIONS

Switching from brand to generic lamotrigine is largely devoid of adverse health outcomes; however, creating an incentive to ensure a greater proportion of patients switch to generic lamotrigine is required to achieve maximal financial savings from a policy of generic reference pricing.

Predictors of statin compliance after switching from branded to generic agents among managed-care beneficiaries

OBJECTIVES

To identify patient demographics and characteristics associated with compliance to statin therapy after switching from branded to generic agents

DESIGN

Retrospective cohort study using electronic health records and pharmacy claims data from Sutter Health's ambulatory-care medical network

PATIENTS

Managed-care beneficiaries, ≥ 18 years of age, who were switched from branded to generic statins between 1 January 2003 and 31 December 2012 MAIN MEASURES: Compliance was calculated as days of therapy dispensed divided by days from first to last generic prescription fill over 6 months, and was defined as a medication possession ratio ≥ 0.80. We used multivariable logistic regression to assess factors associated with compliance. Adjusted ORs and 95% CI were generated.

KEY RESULTS

We identified 5,156 patients who were switched from branded to generic statins; 73% of patients were compliant in the 6 months after switching. After statistical adjustment, higher compliance was associated with each 10-year increase in age (OR: 1.13; 95% CI: 1.07, 1.19; p < 0.001), receipt of a generic statin equivalent in potency to the prior branded statin (OR: 1.41; 95% CI: 1.16, 1.70; p < 0.001), and compliance with prior branded statin (OR: 4.68; 95% CI: 4.07, 5.39; p < 0.001). Lower compliance was seen among Hispanic patients compared to non-Hispanic white patients (OR: 0.68; 95% CI: 0.52, 0.91; p = 0.009). Also, a switch to a higher potency generic statin, regardless of prior dose/potency, was negatively associated with compliance after switching (OR: 0.87; 95% CI: 0.80, 0.94; p = 0.001).

CONCLUSIONS

The majority of patients switched from branded to generic agents were compliant with therapy in the first 6 months after switching. The potential for non-compliance to generic statin therapy, particularly among younger or Hispanic patients or when dose/potency changes are made, should be considered prior to switching. For these patients, counseling or close monitoring may be required to optimize generic interchange.

Understanding patients' perspective in the use of generic antiepileptic drugs: compelling lessons for physicians to improve physician/patient communication

Background

Epilepsy is a condition in which consistency of treatment is paramount to successful management and for most patients, effective seizure control can be achieved. Given the severe consequences of even a single breakthrough seizure, patients should be afforded every opportunity to succeed on their given regimens.

Discussion

Some experts argue that global policy on generic antiepileptic drug substitution in epilepsy should be limited – occurring at the discretion of and with careful monitoring by the physician. While the debate continues, physicians still have daily responsibilities to their patients to help them best manage their epilepsy within the context of the current environment – the reality of which may involve switching to a generic antiepileptic drug or navigating various formulations between generics.

Summary

To provide context, this paper first reviews the main "hot button" issues fueling the ongoing generic debate, including a broad overview of the current state of the literature. The main goal however is to provide physicians with a patient perspective on generic antiepileptic drug use in epilepsy as a source of clinically useful, everyday advice to improve communication and increase patient self-advocacy, both of which are necessary for optimal patient outcome.

Pharmacists' Views on Generic Medicines: A Review of the Literature

The aims of this paper were to identify and review the literature on pharmacists' views and practices on the use of generic medicines. Using appropriate keywords pertaining to the subject matter, an extensive literature search was undertaken using indexing services available in the authors' institution library. These electronic databases were searched for full-text papers written in the English language during the period from 1980 until September 2007. Based on this search, 13 studies were identified. The majority of studies are from the United States, with few from Europe and Asia. All retrieved studies, except one, used quantitative methodology. Most of the studies showed that pharmacists' views and behaviours towards generic medicine utilisation were affected by economic considerations, quality and bioequivalency of generic medications, drug therapeutic class, and other actors (the physicians, the patients, and public health officials). This review suggests that although in general pharmacists were positively inclined towards generic medication use, they have some considerations that determine to what extent they will support generic medicine use. These are economic, scientific, and policy-related considerations that are likely to remain matters for discussion in the future among pharmacists and their professional organisations.

Therapeutic equivalency of generic antiepileptic drugs: results of a survey

Controversy persists whether generic antiepileptic drugs (AEDs) are interchangeable with brand name drugs with respect to efficacy and adverse events. Three hundred and one neurologists responded to a survey regarding generic AEDs mailed to 6420 neurologists, for an overall response rate of 4.7%. One hundred and ninety-six (67.8%) neurologists reported breakthrough seizures after a switch from a brand name to generic AED; 93 (32.2%) did not. One hundred and sixty-three neurologists (56%) reported increased side effects in their patients after a switch from a brand name to generic AED; 128 (44%) did not. Fifty-two (18.4%) neurologists agreed that the Food and Drug Administration standards for AED bioavailability are sufficiently narrow; 231 (81.6%) did not.