Table 1.

Studies Involving β-Blockers

Source	Drugs Studieda	No. of Patients (Age Mean or Range, y)/ Duration	Study Design	Population (Setting)	Jadad or Newcastle-Ottawa Scoreb	Results	Listed Source of Funding
Ahrens et al,25 2007	Toprol XL vs 8 versions of long-acting metoprolol	49673 (56)/4 y	Retrospective cohort study	Patients affiliated with 3 German health insurers (non-US)	8	No excess risk of hospitalization for cardiovascular events after adjustment for confounding (OR, 1.04–1.06; 95% CI, 0.89–1.21)	Generic manufacturers
Portoles et al,26 2005	Coreg vs carvedilol	24 (22.8)/1 dose of each with washout	RCT with crossover	Healthy subjects (non-US)	2	No significant differences in HR, BP, PR length, tolerability	Not listed
Mirfazaelian et al,27 2003	Tenormin vs atenolol	12 (NA)/1 dose of each with washout	Bioequivalency study: double-blind RCT with crossover	Healthy subjects (non-US)	2	No significant differences in reductions of HR, BP	Not listed
Bongers and Sabin,28 1999	Toprol XL vs long-acting metoprolol	52 (62)/4 wk for each product	Double-blind RCT with crossover	Outpatients with stable angina and 6 proven ST-segment depressions on ambulatory ECG (non-US)	3	Both significantly reduced ischemic events; no significant difference in reductions of HR or BP, signs of ischemia on telemetry (P = .21), anginal attacks (P = .34), nitrate use (P = .13), or adverse events (P = .08); median HR slightly less for brand-name (P = .05)	Brand-name manufacturer
Chiang et al,29 1995	Tenormin vs atenolol	23 (59)/4 wk of each with washout	Double-blind RCT with crossover	Outpatients with hypertension (non-US)	3	No significant differences in reductions of HR, BP	Not listed
Sarkar et al,30 1995	Tenormin vs atenolol	31 (NA)/1 dose of each with washout	Bioequivalency study: RCT with crossover	Healthy subjects (US)	2	No significant differences in reductions of HR, BP	Generic manufacturer
Carter et al,31 1989	Inderal vs Inderal LA (long-acting) vs propranolol	15 (46)/4 wk of each with washout	Single-blind RCT with crossover	Outpatients with hypertension (US)	3	No significant differences in reductions of HR, reductions of BP, tolerability	National Institutes of Health
el-Sayed and Davies,32 1989	Inderal vs propranolol vs placebo	12 (NA)/1 dose of each with washout	Double-blind RCT with crossover	Healthy subjects (non-US)	2	No significant differences in change in resting HR, SBP, postexercise values	Not listed
Sanderson and Lewis,33 1986	Inderal vs propranolol	1700 (68)/Half switched to Inderal LA for 4 wk; then all switched for 4 wk	Retrospective cohort study	Outpatients with multiple indications for β-blocker (non-US)	3	Increased incidence of self-reported adverse effects among group taking generic at initiation of study (P < .001) (difference extinguished after all switched to Inderal LA, P = .15)	Not listed

Abbreviations: BP, blood pressure; CI, confidence interval; ECG, electrocardiogram; HR, heart rate; NA, not available; OR, odds ratio; RCT, randomized controlled trial; SBP, systolic blood pressure.

^aToprol XL and Tenormin are manufactured by AstraZeneca, Wilmington, Delaware; Coreg, GlaxoSmithKline, London, England; and Inderal, Ayerst Laboratories, Radnor, Pennsylvania.

^bThe Jadad score range is 1–5 for RCTs; the Newcastle-Ottawa score range, 1–9 stars for observational studies.