Can beta blockers paradoxically increase heart rate?

Answer 1

Beta-blocker is a shortened name for beta-adrenoceptor blocking pharmaceuticals (medications). Beta blockers block the effects of noradrenaline and adrenaline (epinephrine) on the heart muscle. The medicine does this by sitting at the receptors which normally would pick up those cardiac stimulating hormones. Imagine the beta blocker as if in a soccer game. The strong hormones, on the one team, run fast and make the heart speed up. Beta blockers act as very efficient and highly skilled "goalies", sitting right in front/at the doorway to the "goal". Beta blocker "goalies" successfully stop those high powered hormone's attempts to reach the cardiac cells. In doing so, the "goalie" not only deflects the noradrenaline and adrenaline's "hyper" actions, it keeps those from getting the heart into a more "hyper" state, similar to the increased heart rate and stress on the heart during a "flight or fight" response.

Since beta blockers block the hormone effects, it SLOWS the heart rate. It should never produce a paradoxical (unintended or unexpected opposite); e.g. higher heart rate. However, there is some evidence that there can be a paradoxical effect with developing other heart problems. But the risk of not treating a pounding high heart rate and blood pressure, which can lead to stroke or cardiac exhaustion, heart failure, or even death outweighs the 'possibility' that the medicine might cause another problem (or might not).

These meds are only given when the heart muscle needs extra protection. Some conditions include: angina, high blood pressure, some types of abnormal heart rhythms (arrhythmia) but not in all types, heart failure, heart attack (myocardial infarction), anxiety, overactive thyroid symptoms, glaucoma and migraine. For arrhythmias, the choice of med depends on the type of arrhythmia (atrial; ventricular; to name two), and the cause of the arrhythmia. For example, most "electrical" problems with the heart involve the hormones, so the med works pretty well. But structural causes will need other treatment in addition to the medicine. Some generic names for beta blockers include: acebutolol, atenolol, bisoprolol, carvedilol, celiprolol, labetalol, metoprolol, nadolol, nebivolol, oxprenolol, pindolol, sotalol, propranolol and timolol, along with a host of brand names and other generic names. Most often, these meds are given long term, but the patient and the effects of the meds must be monitored.

Beta blockers often need titrated-- meaning, slowly adjusted up (and down)--for each individual patient. A doctor should not start a person on the maximum dose, because the effect on the person is very individualized. So a patient could continue to have some cardiac symptoms or "runs" of symptoms in early therapy especially. Your doctor will decide whether to slowly increase your beta blocker depending on your HR, BP, and other assessments, like EKG. Your doctor may decide to switch meds, add more medication, or choose a different treatment altogether. But this is so individualized that only your cardiac physician can speak to what you might need.

If you are still experiencing heart symptoms--which can include a host of symptoms in each person including tachycardia and high blood pressure-- call your doctor for guidance.

Remember to :

1. never, ever cut in half, chew, or crush a beta blocker -- they are strong goalies but splitting them or breaking them can lead to serious problems! The "goalies" can't be effective when there are too many on the field at once--like what would happen if all the med enters your bloodstream too quickly.
2. never double a dose, even if you forgot a dose; just begin again with the next scheduled dose. Ask your doctor how much time he wants between a "make up" dose and "the next scheduled dose"-- most docs will say just to skip the missed one, because too much med can cause negative effects.
3. never eat or drink foods or beverages that are on your Restricted List; some interfere with the med.
4. take care when going to standing up after sitting or lying down; SIT if you feel faint or dizzy.
5. report any NEW symptoms
6. report if old symptoms persist even in temporary runs
7. not become heart consumed-- Some people can heighten their fears and anxiety by constantly listening to their heart beat or taking their pulse. Expect to not feel 100% well but don't let this problem dominate your daily life. Breathe, watch TV, rest, relax.
8. attend ALL follow up appointments
9. For those who previously exercised, remember that beta blockers will make it harder to reach a "target heart rate". Instead, use the The Borg Scale of Perceived Exertion and talk to your doctor to determine what your new target HR should be.
10. Tell new doctors you take a beta blocker.

Answer 2

No.