Calcium channel blockers definition

ACE inhibitors and angiotensin-receptor blockers (ARB) have definite benefits in patients with nephropathy and are believed to have renoprotective effects in most patients. Due to their ability to cause an initial bump in serum creatinine, these agents should be used cautiously when employed in combination with the calcineurin inhibitors. The dihydropyridine calcium channel blockers have demonstrated an ability to reverse the nephrotoxicity associated with cyclosporine and tacrolimus (Table 52-8). In general, antihypertensive therapy should focus on agents with proven benefit in reducing the progression of cardiovascular disease and should be chosen on a patient-specific basis.55 See Chapter 2 for further recommendations for treating HTN. 

The (—) isomer of the L-type calcium channel blocker (+)-niguldipine is dexniguldipine. This agent binds to an intracellular domain of P-gp with a K, of 10 nm. In addition, this compound can block RNA synthesis at 5 pM and possesses some anticancer activity (302). Currently, only a few studies have been conducted to evaluate the use of this compound as a P-gp modulator. Definitive results are yet to be reported. 

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