有读者来信认为使用胍乙啶后血压降低,再并用氯丙嗪其血压应该更下降。这是可以理解的。正如来信所提的氯丙嗪既有α阻断作用又能直接扩张血管……。可是氯丙嗪还有一个作用是阻断去甲肾上腺素能神经末梢摄取胍乙啶进入神经末梢的囊泡,胍乙 Some readers believe that the use of guanethidine after lowering blood pressure, and then with chlorpromazine its blood pressure should be more decreased. This is understandable. As mentioned in the letter, both chlorpromazine α blocking effect and direct dilatation of blood vessels ... .... However, chlorpromazine is also a role in blocking norepinephrine nerve endings uptake of guanethidine into the nerve endings of vesicles, guanidine B