Heart glycosides

Heart glycosides - substances selectively strengthens contractions of the heart. Heart glycosides - substances of plant origin. These include glycosides different types of naperstanki (see), strophanthus (see Strofantin), Adonis (see), Lily of the valley (see), treacle, kandira (see Tsimarin), jute (see Autorized, Corporate), alwainia (see Paraplatin), oleander (see Nerilyn), moroznika, sea onions and other
Heart glycosides increase the force of heart contractions due to the direct effect on the myocardium. The effect determines the therapeutic value of cardiac glycosides. In heart failure these products restore the strength of heart contractions and thereby return the ability to maintain the necessary minute volume of blood flow without the effects of stagnation.
Heart glycosides slow down the rhythm of the heartbeat. This effect is connected with the reflex increases tone wandering nerve. In patients with heart failure, accompanied by tachycardia, slow heart rate after administration of cardiac glycosides especially pronounced. Ischemia heart rate leads to an increase in diastolic pause, which is an additional factor contributing to the therapeutic action of cardiac glycosides in heart failure.
Heart glycosides have a significant impact on the processes of providing the muscles of the heart energy. Under the influence of cardiac glycosides inadequately functioning heart starts to produce a lot of work at relatively lower consumption of oxygen.
Along with the action on the heart individual heart glycosides may have effects on the Central nervous system. Soothing effect of a number of cardiac glycosides (Lily of the valley, Adonis) is widely used in medical practice.
According to the extent of absorption from the gastrointestinal tract, the speed of onset of effect and duration of action of various cardiac glycosides are significantly different from each other. Well absorbed after ingestion of drugs naperstanki, oleander, sea Luke, moroznika. In contrast, drugs strophanthus, Lily of the valley, Adonis, treacle absorbed from the gastrointestinal tract bad. In this regard, they should be administered intravenously.
The effect of digitalis and oleander develops slowly. In this regard, particularly characteristic of the drug digitalis digitoxin. He begins to act only after 30 minutes - 2 hours after intravenous administration, and the maximum effect occurs within 4-12 hours. Fast effect causes strophanthin. Its effect manifests itself after 5 to 10 minutes after intravenous injection and reaches through 1-1 .5 hours. Approximately the same act drugs Lily of the valley (converstatin, korglykonum), treacle (erisimi), kandira (tsimarin). Therefore they are used for emergency aid in case of acute heart failure.
Many cardiac glycosides (drugs naperstanki, kandira, oleander, sea Luke) long linger in the body. This determines the large duration of their actions and the ability to cumulation (see). For example, digitoksin remains in the body in 2-3 weeks after a single injection. The use of such drugs requires great care, because there is always the risk of overdose. Drug selection and method of administration depends on the evidence. In acute cardiovascular insufficiency and in other cases, when you need immediate assistance, use of intravenous drugs, providing fast, strong, albeit short-lived action (strofantin, converstatin). In chronic cardiovascular insufficiency usually apply heart glycosides, causing the overall effect when administered (digitoksin, gitoksin, digoxin, nerilyn and others).
Heart glycosides with a strong cumulation (digitalis preparations, oleander, sea Luke) apply predefined schemes. First, during the 2-4 days, the body introduce such a dosage that provides a full therapeutic effect. After that the patient is prescribed maintenance doses, offsetting the amount of the drug that is inactivated and excreted from the body during the day.
Overdose heart glycosides may cause ischemia palpitations, arrhythmia, nausea, vomiting. In fatal poisoning comes of ventricular fibrillation and cardiac arrest. When poisoning cardiac glycosides apply potassium chloride. Administered intravenously (3 g per 500 ml of 5% glucose solution drip) or to the inside (just 4 grams of potassium chloride in the form of 10% solution in the next 1 g 3 times a day).