Clinical equivalence of generic and brand-name CVS drugs - JAMA

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Clinical Equivalence of Generic and Brand-Name Drugs Used in

Cardiovascular Disease

A Systematic Review and Meta-analysis

S. Kesselheim, MD, JD, MPH; S. Misono, BA; Joy L.

Lee,

BA; Margaret R. Stedman, MPH; M. Alan Brookhart, PhD; Niteesh K.

Choudhry, MD, PhD; H. Shrank, MD, MSHS

JAMA. 2008;300(21):2514-2526.

Context. Use of generic drugs, which are bioequivalent to brand-name

drugs, can help contain prescription drug spending. However, there is

concern among patients and physicians that brand-name drugs may be

clinically superior to generic drugs.

Objectives. To summarize clinical evidence comparing generic and

brand-name drugs used in cardiovascular disease and to assess the

perspectives of editorialists on this issue.

Data Sources. Systematic searches of peer-reviewed publications in

MEDLINE, EMBASE, and International Pharmaceutical Abstracts from

January

1984 to August 2008.

Study Selection. Studies compared generic and brand-name

cardiovascular

drugs using clinical efficacy and safety end points. We separately

identified editorials addressing generic substitution.

Data Extraction. We extracted variables related to the study design,

setting, participants, clinical end points, and funding.

Methodological

quality of the trials was assessed by Jadad and Newcastle-Ottawa

scores,

and a meta-analysis was performed to determine an aggregate effect

size.

For editorials, we categorized authors' positions on generic

substitution as negative, positive, or neutral.

Results. We identified 47 articles covering 9 subclasses of

cardiovascular medications, of which 38 (81%) were randomized

controlled

trials (RCTs). Clinical equivalence was noted in 7 of 7 RCTs (100%)

of

â-blockers, 10 of 11 RCTs (91%) of diuretics, 5 of 7 RCTs (71%) of

calcium channel blockers, 3 of 3 RCTs (100%) of antiplatelet agents,

2

of 2 RCTs (100%) of statins, 1 of 1 RCT (100%) of angiotensin-

converting

enzyme inhibitors, and 1 of 1 RCT (100%) of {alpha}-blockers. Among

narrow therapeutic index drugs, clinical equivalence was reported in

1

of 1 RCT (100%) of class 1 antiarrhythmic agents and 5 of 5 RCTs

(100%)

of warfarin. Aggregate effect size (n = 837) was –0.03 (95%

confidence

interval, –0.15 to 0.08), indicating no evidence of superiority of

brand-name to generic drugs. Among 43 editorials, 23 (53%) expressed

a

negative view of generic drug substitution.

Conclusions. Whereas evidence does not support the notion that

brand-name drugs used in cardiovascular disease are superior to

generic

drugs, a substantial number of editorials counsel against the

interchangeability of generic drugs.

Dr.Santosh