Can't help you with the sex life part, as I'm a female, but I can share my experience switching from a beta blocker to diltiazem. I have been taking beta blockers for 8 years for SVT and afib. I had an episode of afib and was in the hospital is Sept. They took me off the beta blocker and put me on diltiazem. It didn't control my heart rate like the beta blocker. My resting heart rate went from upper 60s to the low 80s. After a few days without my beta blocker, I ended up in the ER, in sinus tachycardia with a rate of about 120. Long story short, it did not do a good job of keeping my heart rate down.
Diltiazem is pretty useless for sinus tachycardia. It can increase AV conduction time and be somewhat helpful for reducing the heart rate in the setting of Afib/Aflu, and help decrease ectopic atrial activity (PACs and atrial tachycardia).
If you have sinus tachycardia and can't tolerate beta blockers, try ivabradine. Another option is to try either a combined alpha and beta blocker to increase peripheral blood flow (like carvedilol or labetalol) or choosing a maximum selective beta blocker like nebivolol or bisoprolol.
Diltiazem can even make sinus tachycardia worse because it lowers blood pressure and can cause reflex tachycardia.
I don't think I'll even try the Diltiazem, kind of scares me based on lot of the negative reviews I've heard about it.
I think drinking too much coffee in the mornings may have played a role in the tachycardia. I usually drink 1-4 cups of black coffee. Maybe I'll cut back to one cup and see how that works.
I might ask about invabradine.
So if I stay on my low dose of Metoprolol, and start Cialis as-needed, will that help give me reliable erections during sex, while controlling my heart rate?
Cialis will help, but wouldn't it be better to not need it? I believe some of the reason for your ED is your fear of rapid heart rates during sex, as well as your expectations of Metoprolol to cause problems.
Your heart rate is supposed to increase during sex, exercise and standing up. Try to leave your heart to itself. It won't stop - even if the heart rate should hit 200 bpm or more.
But I think I would consider another beta blocker or ivabradine before I would try diltiazem. It will probably do nothing at all, or worsen the problem.
I just really don't want to take the diltiazem. The doc said it's not any more potent than metoprolol, but I hear all the negative comments about it and 120mg a day seems a bit high. And if it won't keep my heart rate down then it won't be of use anyway.
The fear of rapid heart beat is there, even though I know it probably isn't dangerous, it's a bit unnerving. And even if I'm totally relaxed, the last few times I tried to have sex, I could not keep an erection. And so then my anxiety goes up again, and my confidence goes down.
So it's a vicious cycle. Right now I'm leaning towards staying on whatever minimal dose of metoprolol I can get away with, and adding the Cialis to try and get a sex life back. I'm hoping since the Cialis is supposed to lower blood pressure anyway, maybe it will also keep my heart rate down during the deed assuming it gets me hard.
Cialis will unfortunately not slow down your heart rate. It's effect on blood pressure happens because it dilates the arteries.
The only way to know for sure if it works is to try. I strongly believe it will work, but no one can say for sure.
Good luck :-)
your describing symptoms of P.O.T.S have you ever been checked for that ? a lot of doctors are unfamiliar with it and it gets missed.