Renoprotective effects of the L-/T-type calcium channel blocker benidipine in patients with hypertension.

The renoprotective effects of benidipine, a calcium channel blocker (CCB) developed in Japan, are reviewed herein. Benidipine has a sustained antihypertensive effect independent of its blood concentration since it binds to dihydropyridine (DHP) receptors via a "membrane approach" (approach to the cell membrane followed by long retention at the DHP binding site). Benidipine dilates glomerular afferent and efferent arterioles equally through inhibition of Ttype Ca channels. Thus, it may cause a decrease of intraglomerular pressure and is superior to CCBs (capable of inhibiting only L-type Ca channels) in terms of suppression of proteinuria. Additionally, benidipine suppresses worsening of renal function more powerfully than CCBs (suppressing only L-type Ca channels), allowing better prognosis as to renal function. The inhibitory effect of benidipine on T-type calcium channels results in the suppression of aldosterone formation in the adrenal glands and of oxidative stress induced by aldosterone. Thus, the aldosterone-inhibitory and antioxidant activities of benidipine mediated by inhibition of T-type calcium channels would result in renoprotection and suppression of disease progression in hypertensive patients with chronic kidney disease (CKD). If such patients have proteinuria, renin-angiotensin system (RAS) inhibitors are used as first-line drugs, but benidipine, as an L-/T-type CCB, is recommended when they require some concomitant drugs. Moreover, the superiority of RAS inhibitors has not been demonstrated in hypertensive patients with CKD and without proteinuria. Thus, in such patients, benidipine should be considered as a first-line antihypertensive drug.