Target heart rate while on 12.5 Atenolol?? / Ambien and atenolol

[desertshrink]

hi - 1) what should my target heart rate be while doing cardio for 45 min at the gym? I am 44 YO and weigh 138 lbs...I usually get it between 140-150....but, while on 12.5 of Atenolol, I am between 110-120 beats, and am working hard...is this normal??

also, 2) on 25mg atenolol, my BP dropped to 84/51 while lying down. When it is this low, can I take 5 mg Ambien for sleep, too??....or will the Ambien lower it further? I was not able to sleep worrying about this. Thanks for your help.

[Ihatepalps2]

hi! I was on 50 mg in the morning and 50 mg atenolol at night for 17 years. So my dose was huge compared to yours...i asked my doctor your very question about exercising and the atenolol. He said its virtually IMpossible (at my dose, though) to get my HR up much beyond 105...110 max while on Aten. Your dose, so tiny, may not hold it down as much as mine did. He didnt want me to try--just making the heart work that much harder since its working to keep the HR lower. He said I still get cardio workout benefit with it lower while working out.

[Brooke_38]

Hello...

Beta blockers slow your heart rate, which can prevent the increase in heart rate that typically occurs with exercise. This means that it might not be possible for you to reach your target heart rate. The number of heartbeats per minute you should have to ensure you're exercising at the proper intensity level. No matter how hard you exercise when taking a beta blocker, you may never achieve your target heart rate. There's no precise way to predict the effect of beta blockers on your heart rate.

You can also try lowering your target heart rate by the amount that your resting heart rate has been lowered by the beta blocker. For example, if your resting heart rate has decreased from 70 to 50, then try working at a target heart rate 20 beats per minute lower than what you used to do. This way of calculating your adjusted target heart rate isn't precise, and sometimes the peak exercise heart rate is affected much more than is the resting heart rate. An exercise stress test is the best way to establish a new target heart rate on beta blockers.

Regarding the lower Bp; When you are lying down you increase venous capacitance, which decreases preload on the heart, decreased filling volumes leads to decreased contractility via the Frank-Starling equation, and thus decreased cardiac output, leading to decreased blood pressure.

Or, to say it simply, when you lie down, your veins hold more blood, less blood coming back to the heart equals less force of blood going out of the heart, equals lower blood pressure.

The reason the body doesn't reflexively increase blood pressure to compensate for this is because when you are lying down the heart is not pumping against the force of gravity to get blood to your brain, and since you brain is getting enough oxygen, it's happy to keep the lower blood pressure.

There are no contraindications for taking Atenolol and Ambien together. They are different classes of drugs and work in and on different parts of the body. Atenolol is a beta blocker and Ambien is in a class of drugs called benzodiazepines. Unless instructed by your Dr, there is no reason you can't take both. :)