Atenolol and Nifedipine - Technical Details?

Both Atenolol 50mg and Nifedipine 60mg is used to lower HBP. However, I have a few questions:

1. How do each of them help reduce the blood pressure? I've checked the database of drugs on steadyhealth, but it's too technical for me. Anyone able to help?

2. Also, Nifedipine is said to inhibit calcium ions, so how does calcium ions affect your blood pressure?

Thanks alot.

I don't know how nifedipine works, but here's some information I dug up on atenolol for you!

Atenolol is a so-called β1-selective (or 'cardioselective') drug. That means that it exerts greater blocking activity on myocardial β1-receptors than on β2 ones in the lung. The β2 receptors are responsible for keeping the bronchial system open. If these receptors are blocked, bronchospasm with serious lack of oxygen in the body can result. However, due to its cardioselective properties, the risk of bronchospastic reactions if using atenolol is reduced compared to nonselective drugs as propranolol. Nonetheless, this reaction may also be encountered with atenolol, particularly with high doses. Extreme caution should be exerted if atenolol is given to asthma patients, who are particularly at risk; the dose should be as low as possible. If an asthma attack occurs, the inhalation of a β2-mimetic antiasthmatic, such as hexoprenaline or salbutamol, will usually suppress the symptoms.

Does that make sense to you at all? I can break it down if you like. Thanks.

How about Blood Pressure?