However, the binding site of dihydropyridine drugs (such as nifedipine) is outside the cell membrane, which is not affected by the channel switch, that is, no matter how fast the channel is opened and the heart rate is fast, the blocking effect will not be strengthened or weakened, and the influence on the heart is smaller than that of verapamil, so there is no frequency dependence.
Usage dependence is also called frequency dependence or heart rate dependence.
Page 188 of Pharmacology, the ninth edition edited by Yang Baofeng mentioned: "Hydrophobic dihydropyridine drugs, such as nifedipine, combine with inactivation channels to prolong the recovery time after inactivation. Therefore, the dependence on the use of such drugs is weak, and the influence on the autonomic activity, heart rate and cardiac conduction of the heart is small. " Why?
A: Nifedipine binds to inactivated unopened channels, and the binding site is outside the cell membrane. Therefore, this kind of drugs are less dependent on the use, and have less influence on the heart than verapamil, and have less influence on the autonomic activity, heart rate and heart conduction of the heart.
References:
[1] Guo. Drug reverse use dependence [J]. Journal of Clinical Electrocardiology, 20 14, (2): 155
[2] Liu Haiqing, Zhang Shiliang and Yang Jie. Discussion on the mechanism of dihydropyridine combined with non-dihydropyridine drugs in the treatment of refractory hypertension [J]. Health Guide (Medical Edition), 20 14, (10): 240
[3] Yang Baofeng, edited by Chen Jianguo; Zang Weijin, deputy editor of Wei Minjie. Pharmacology? The ninth edition [M]. Beijing: People's Health Publishing House, 20 18.
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