The use of cardiac glycosides in heart failure
Cardiac glycosides are drugs of vegetable or chemical origin that have a positive impact on the heart and increase myocardial contractility. To glyconeogenesis plants include Foxglove, Lily of the valley, oleander, Adonis, and others. Increase rate and force of cardiac contractions occur without increase in oxygen demand.
A characteristic feature of preparations is the action aimed at narrowing the veins and arteries. Often this action can cause a rise in pressure, that is important to consider their appointment. To avoid this effect in the slow introduction of drugs.
The principle of operation
In the interaction of substances with water is released Gelikonov and aglycones. The mechanism of action is based on the work aglycones. Glikony have no effect on the heart, but they contribute to the dissolution of glycosides and their combination with protein of plasma. Therefore, glikony ensure the penetration of the glycosides to the cells and have a direct effect on the mechanism of action of the drug.
After oral administration the drug enters the stomach, and then into the blood stream. Further there is a deposition of elements of the drug in the tissues of the myocardium. The action of the drug due to the strength of the bond of glycosides to the protein of plasma. The strength of the bond determines:
- the accumulation of active substances in the blood;
- the duration of drug action;
- overcoming the blood-brain barrier.
The stronger the relationship of the active substance with the protein, the greater the duration of action of the drug and more pronounced effect of cumulation.
The effect of the drug has a significant impact on the functioning of the heart muscle. There is a decrease of the period of cardiac contractions and increased the duration of the rest.
- Long-acting products. After oral intake can have an impact on the cardiovascular system for several days. Maximum efficiency is achieved after 9 to 12 hours. Drugs of this group often cause an overdose, because it can accumulate in the body. When administered intravenously, a positive effect is observed after 2 hours previously. Means continuous duration of action is derived from Foxglove by synthesizing. They can quickly be absorbed into the stomach and to penetrate into heart tissue, improving its contractile function.
- Drug expectancy effects. The process of removing them from the body occurs over several days. Maximum effect after administration can be expected after 6 hours. This group includes substances synthesized from rusty and woolly digitalis and Adonis. Moderate ability of plants toabsorption cause slow action of medicines. When injected into a vein the effect occurs after a quarter of an hour and lasts for up to three days.
- Means a short exposure. They are characterized by intravenous. Cumulative properties, these drugs do not have and are means of ambulance. Provide unstable, but fast effect. When injected into a vein the effect occurs after 5 minutes and lasts up to two days.
In which cases are assigned
The use of drugs in heart failure is performed in the following cases:
- Acute disorders of the cardiovascular system occurred on the background of arrhythmia in the Atria.
- Chronic insufficiency of the cardiovascular system.
- Permanent atrial fibrillation in conjunction with a high heart rate. In this case, the therapy starts with administration of maximum doses. This technique is assigned to until will not decrease the severity of the failure. Followed by preventive treatment, which is characterized by the drug in smaller doses. If there are signs of toxic poisoning by drugs, medicaments canceled, and then conducted therapy drugs potassium and magnesium.
- Circulatory failure.
- Supraventricular tachycardia.
In children due to intoxication often there is an arrhythmia. Adults and elderly – mental impairment. When a large overdose can be fatal. Amid side effects of taking glycosides it is necessary to call an ambulance. In parallel, the necessary administration of activated charcoal and gastric lavage, taking a laxative.
List of drugs used to eliminate the signs of intoxication:
- Panangin, potassium orotate, potassium chloride to supply potassium in the myocardium, where under the influence of the glycosides is a deficit item.
- Citation salts and Trilon provide binding molecules of calcium.
- Lidocaine, inderal, propanolol – help get rid of arrhythmia.
- Difenin is used for removal of glycosides from the body.
Side effects of drugs
During the reception glycosides may experience the following side effects:
- enlarged Breasts;
- headaches and dizziness, insomnia;
- abnormal heart rhythm;
- lack of appetite;
- hallucinations and clouding of consciousness;
- damage to the vessels of the mucous membranes, leading to bleeding;
- changing ideas about the color of objects.