Treatment with beta-blockers must begin "gradually", ie with low dosages that increase only slowly. The symptoms may also initially deteriorate. The therapeutic success of a beta-blocker therapy usually begins after three months. Therefore, beta-blockers should only be administered to patients who have been in stable condition for some time.
Side effects are possible
Beta blockers should not be used for certain cardiac arrhythmias, very slow heartbeats, extremely low blood pressure, asthma and some other conditions. Side effects include:
- allergic skin reactions,
- Tiredness, insomnia, decreased lacrimation,
- fluctuating blood glucose levels,
- increased dyspnoea,
- Potency disorders.
The side effects usually disappear after discontinuation of the drug - in many patients, the change to the drug of another manufacturer helps. Therefore, patients should be in close contact with their attending physician during treatment with beta-blockers and should report any complications directly to them.
However, for patients whose hypertension is primarily stress-related, treatment with beta-blockers may become problematic if stress is not eliminated. Because this class of drugs can lead to increased fatigue and loss of performance, a vicious cycle of "stress-high-pressure-drug-performance-decrease-higher-stress -..." may arise. Especially young, dynamic people are in danger of getting into this cycle. The reasons for the high pressure must therefore be clarified before the start of the treatment and permanently checked during the treatment.
Beta-blockers can also be used in hyperthyroidism, in liver cirrhosis with portal hypertension, circulatory disorders in the heart and cardiac arrhythmias.
Application of beta-blockers are manifold possible
As the name implies, beta-blockers block beta-receptors found on many different organs, resulting in the wide range of applications of beta-blockers:
- When hyperthyroidism, they are usually only used when an increased heart rate (tachycardia) is present. For this, various common individual preparations with active substances such as metoprolol or bisoprolol can be used. Special case is the so-called thyrotoxic crisis, a derailment of hyperthyroidism, which can be triggered for example by infections or iodine-containing contrast agent. Then the betablocker propranolol is preferably used, which suppresses the production of active thyroid hormones and also acts against the symptoms of tremors and restlessness in the clinical picture.
- In circulatory disorders in the heart - ie coronary heart disease - and after heart attacks, beta blockers are also used to lower the heart rate. Because of this, the heart has to do less work and the oxygen consumption is lower, which makes sense because the reduced blood flow to the heart is supplied with less oxygen. Many of the common beta-blockers can also be used as a single preparation.
- The same applies to various forms of cardiac arrhythmias in which the heart rate is increased (for example, in atrial fibrillation).
- In liver cirrhosis with portal hypertension, however, propranolol, more rarely carvedilol, is usually used. These two beta-blockers lower the pressure in the portal vein by leading to an expansion of the vessel.
Beta blockers as combination preparations
Beta-blockers are often available as combined preparations on the market. Combination preparations usually combine beta-blockers with a dehydrating agent (Hydrocholorothiazide; HCT) and are particularly useful in high blood pressure therapy, as HCT decreases blood pressure. They are also used for moderate to severe heart failure when water retention occurs.