P3805Evaluation of blood pressure lowering effect by generic and brand-name antihypertensive drug treatment: a prospective multicenter study in China

Abstract

Background: The rapidly increasing cost of hypertension medications has been a serious burden for public health, which is up to approximate 210 billion RMB and accounts for 6.61% of the total health expenditure in 2013 in China. Generic antihypertensive drugs with low price can save a great amount of money on health care. A recent meta-analysis claimed the clinical equivalence between generic and brand-name drugs in treating cardiovascular diseases. However, most studies included small population and provided very limited information for efficacy outcomes. Controversy still exists regarding the effective consistency between generic and brand-name medications. Purpose: To compare the magnitude of blood pressure lowering effect and evaluate the trajectory patterns of blood pressure during the follow-up in the generic and brand-name antihypertensive drugs. Methods: A population-based study was conducted by recruiting 13,987 individuals from August 2009 from 18 clinic centers located at 12 provinces in China and prospectively followed up 2.2 years (median, range 0.1-7.8 years) (Clinical- Trials.gov No. NCT01703780). Of which, 8,015 eligible hypertensive patients at baseline who received antihypertensive treatment were identified and randomly matched by age and gender using case-control (1:2 ratio) individual matching method to compare the efficacy of generic and brand-name treatment. Results: A total of 1,966 hypertensives in the generic group were matched to 3,932 hypertensives in the brand-name group. The results showed a significant difference in systolic blood pressure (SBP) change during the follow-up, which was -11.7 (95% CI, -13.1 to -10.4) mm Hg for generic group and -9.1 (95% CI, - 10.7 to -7.5) mm Hg for brand-name group (P<0.001), by multivariate generalized liner analysis after adjustment for body mass index, current smoking and drinking status, comorbidities, and annual household income. Patients with lower annual household income (¥<50,000/year) were more likely to use generic agents, and there was no significant difference of SBP change between two groups, which was -6.7 (95% CI, -8.0 to -5.4) for generic group and -5.0 (95% CI, -8.0 to -2.0) for brand-name group respectively. SBP trajectory pattern, assessed by latent mixture modeling (PROC TRAJ), showed a significant difference between two groups: 57.8% patients in generic group had a SBP decrease to 140 mm Hg during follow-up compared to 25.8% patients in brand-name group (P<0.001); in contrast, 69.0% patients in brand-name group had a stable SBP of 120-140 mm Hg from baseline to follow-up compared to 33.4% patients in generic group (P<0.001). Conclusions: Generic antihypertensive drugs are widely used in the real world clinical practice, and our finding supports generics are not inferior to brand-name antihypertensive agents in clinical efficiency, particularly for those having a SBP ≥140 mm Hg.