Substance
Adalat® is a substance that falls into the group of calcium antagonists. Together with the drug Bayotensin, it is one of the most popular representatives of calcium antagonists.
Active substance
The active ingredient of Adalat® is nifedipine. There are a number of other active ingredients, such as amlodipine, felodipine, isradipine, nicardipine, nimodipine, nisoldipine and nitrendipine, which act in a similar way to nifedipine and are therefore called nifedipine-type substances.
Mode of action
Smooth muscle cells, such as those found in the heart or in the wall of blood vessels, react, among other things, to the different calcium concentration in each individual cell. If the calcium in the cell rises, the muscle cells become more contractile, i.e. they contract and perform a muscle movement. At the heart, an increased muscle movement leads to a stronger heartbeat and thus to a rising blood pressure.
At the outer wall of the blood vessel, increased muscle movement leads to a reduction in the lumen of the vessel. The blood must flow faster in order to pass through a smaller diameter at the same time. Here too, the effect is an increase in blood pressure.
Calcium enters the smooth muscle cells via docking sites (so-called receptors). A distinction is made here between voltage-dependent calcium channels and receptor-dependent calcium channels. If the mechanism is not influenced, as is the case with all healthy people, the inflow and outflow of calcium is regulated automatically.
The calcium usually comes from the blood and from the tissue adjacent to the cells. Nifedipine now inhibits this calcium influx by attaching itself to the channels and blocking them. As a result, the influx of calcium is reduced and the muscle cells only receive a reduced supply of the calcium necessary for muscle movement.
All muscle movements of the smooth muscle cells, which are dependent on an increased calcium level, can only be triggered in a reduced way. In the heart this means that calcium antagonists lower the blood pressure (e.g. the substance verapamil). At the vascular muscle cells, a blockage of the calcium channels causes the muscles to contract less, so that the diameter of the blood vessels is not reduced or even expanded. The blood can flow more slowly and the blood pressure drops. While nifedipine-type calcium antagonists are more likely to act on vascular muscle cells, benzothiazepines and phenylalkylamines are more likely to act on the heart and other organs controlled by smooth muscle cells
Fields of application
Calcium antagonists are used to regulate blood pressure in hypertension. Adalat® in particular is used for high blood pressure, especially in so-called hypertensive crises (blood pressure reaches values above 200 mmHg, but there is no organic damage) and in so-called hypertensive emergencies (blood pressure values above 200 mmHg with organic damage). Patients suffering from coronary heart disease are also often prescribed calcium antagonists.
In the context of coronary artery disease, Adalat® is mainly used for the so-called stable angina pectoris. This clinical picture refers to a feeling of pressure on the chest during exercise. The symptoms may also be accompanied by shortness of breath.
In contrast to unstable angina pectoris, where the same symptoms even occur at rest, stable angina pectoris is not yet an absolute emergency. Another area of application is the rare Raynaud’s phenomenon, in which a sudden narrowing of the arterial vessels of the fingers occurs. Patients then usually complain of cold and white fingers.
This condition usually improves after a few minutes and can also be treated by massage. In some cases, however, a calcium antagonist is used to stop the spastic muscle contraction of the finger vessels by reducing the inflow of calcium. In some cases Adalat® can be used as a contraction inhibitor (medicinal: for tocolysis).
However, it is not a first-choice product and is not officially approved for this purpose. However, in patients with concomitant diseases such as high blood pressure or diabetes (“diabetes”), various studies have even shown advantages of the active ingredient of Adalat (nifedipine) over other drugs used to inhibit labour. In particular, severe side effects occur less frequently than with other tovipine inhibitors. However, as Adalat is not approved for this so-called tocolysis, it can only be used as “off-label-use” (contrary to the actually approved provision on the responsibility of the doctor). You can find more interesting information on this topic at: Premature contractions
