Metoprolol can cause blood to thin out


This is how metoprolol works

In stressful situations, the body releases the hormone adrenaline into the blood. This stress hormone reaches all organs of the body via the bloodstream within a very short time and transmits the stress signal by binding to certain receptors (beta-adrenoceptors) of the organs. The affected organs then adapt their activity to the stressful situation - the bronchi expand to take in more oxygen, the muscles are supplied with more blood, the digestive activity is shut down, and the heart beats faster to supply the entire body with more oxygen and energy .

Sometimes this system gets out of hand, in which case, for example, the heart beats too quickly without receiving the signal for it. In the long run, this puts a heavy strain on the body and can lead to serious consequences such as cardiac arrhythmias, blood clots or damage to blood vessels.

The active ingredient metoprolol blocks the adrenaline receptors in the heart very selectively, so that the stress hormone can no longer dock there and develop its effect - the heartbeat remains at a normal level.

The metoprolol taken by mouth (orally) is almost completely absorbed in the intestine, but then about two thirds are broken down by the liver before it reaches its target. Since the active ingredient is excreted relatively quickly via the kidneys (reduction by about half after three and a half hours), prolonged-release tablets or capsules are often used, which release the metoprolol with a delay. This means that the levels of active ingredients in the body remain roughly the same throughout the day, and the drug only needs to be taken once a day.

When is metoprolol used?

The active ingredient metoprolol is approved for the treatment of high blood pressure, cardiac arrhythmias and coronary artery disease, as well as for the follow-up treatment of heart attack patients.

The use of metoprolol for the prevention of migraine attacks seems rather untypical. By regulating blood pressure, however, the active ingredient can reduce the frequency and severity of seizures.

Outside of its approval (“off-label”), metoprolol - taken once - is also used against stress-induced body overreactions (such as stage fright). In the approved areas of application, however, the active ingredient is usually taken long-term.

This is how metoprolol is used

The active ingredient metoprolol is used in the form of its salt with succinic acid (as succinate, "Metoprolol succ."), With tartaric acid (as tartrate) or with fumaric acid (as fumarate).

The most common dosage forms are tablets with delayed release of active ingredients (retard tablets). There are also normal tablets and injection solutions. Combination preparations are also available that contain metoprolol as well as a diuretic or a calcium channel blocker. Patients with high blood pressure often have to take all of these active ingredients, so combining them in one tablet makes it easier to take the medication.

Retard tablets usually only have to be taken once a day, and immediate-release tablets several times a day. The doctor must first determine the optimal metoprolol dosage for the patient.

If you want to stop metoprolol, this should be done slowly and by gradually reducing the dose. Otherwise, a so-called “rebound phenomenon” can occur, with the blood pressure rising reflexively after stopping the drug.

What are the side effects of metoprolol?

Common side effects of metoprolol (affecting one in ten to one hundred people) include tiredness, dizziness (especially when standing up), headache, slow heartbeat, nausea and vomiting. Exercise can also lead to shortness of breath.

What should be considered when taking metoprolol?

The active ingredient metoprolol is broken down in the liver via an often used metabolic pathway through which many other medicinal substances are also metabolized. As a result, metoprolol can interact with a large number of other active substances / groups of active substances:

  • Medicines for depression (antidepressants such as fluoxetine, paroxetine, and bupropion)
  • Medicines for irregular heartbeat (antiarrhythmics such as quinidine and propafenone)
  • Allergy medication (antihistamines such as diphenhydramine)
  • Antifungal agents (such as terbinafine)

Since other drugs can also interact with metoprolol, the doctor will ask before prescribing which other drugs a patient is still using.

Metoprolol can be used during pregnancy if absolutely necessary. With prolonged use, the growth of the unborn child must be monitored, because metoprolol can cause a reduced blood flow to the placenta and thus an undersupply of the child.

If necessary, the active ingredient can be used during breastfeeding. Because it passes into breast milk, possible side effects in the breastfed child should be observed - in individual cases a slowdown in the heartbeat (bradycardia) has been observed.

How to get metoprolol medication

Metoprolol requires a prescription in every dosage and is therefore only available with a prescription from the pharmacy.

How long has metoprolol been known?

Metoprolol was first marketed as a medicinal product in the USA in 1978 in the form of its tartaric acid salt. In the course of extended patent claims, the active ingredient was developed as a succinate by Astra Pharmaceuticals (now AstraZeneca) and approved in the USA in 1992. There are now numerous inexpensive generics containing metoprolol on the market.

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