Brief Answer: some persons have resistant hypertension Detailed Answer: HI, thanks for using healthcare magic Some persons have what is resistant hypertension. This is high blood pressure that is resistant to treatment and requires 3 or more medications to control the blood pressure readings. The medications that you have mentioned (atenolol, spirnolactone,Htz, lisinopril) belong to different drug families. This means that they reduce blood pressure in different ways . Atenolol is a beta blocker, it slows heart rate and widens the blood vessels (causes them to relax) by acting on receptors in the heart and blood vessels. Spirnolactone is a diuretic (helps with fluid loss). It antagonises ( fights against) a chemical in the body called aldosterone . This chemical aldosterone is implicated in hypertension HTZ is also a diuretic but it works in a different way. Lisinopril is a ACE inhibitor. It helps blood vessels to relax, therefore lowering blood pressure. There is a potential risk of increased levels of the electrolyte potassium with the combined use of spirnolactone and lisinopril but this can be detected and monitored by blood tests done by your doctors. I hope this helps, feel free to ask any other questions

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