Verapamil

Verapamil has antianginal and antiarrhythmic activity.

Indications Verapamilla

It is used in the following disorders:

• supraventricular tachycardia;
• exertional angina, having a stable character;
• angina pectoris, in which supraventricular rhythm disorders are noted;
• sinus cardiac tachycardia;
• extrasystole supraventricular type;
• atrial fibrillation;
• hypertensive crisis (intravenous method);
• increased blood pressure.

Release form

The release of a therapeutic agent is performed in tablets or dragees having a volume of 40 and 80 mg, and in addition in tablets with a prolonged type of influence (volume of 0.24 g) and in a 2.5% solution for intravenous injections.

[1], [2], [3]

Pharmacodynamics

Verapamil blocks the activity of Ca channels. The drug has antihypertensive, antianginal and antiarrhythmic effects.

The effect of the drug is based on blocking the activity of "slow" Ca channels located inside the myocardial cells, smooth muscle vascular cells and the conducting cardiac system. At the same time, these channels are present inside the smooth muscles of the uterus, bronchi and urethra. The blockade leads to the stabilization of pathologically increased current of calcium ions inside the cells. By weakening the transmembrane entry of the Ca2 + element inside the cardiomyocytes, the drug reduces the heart rate and the strength of myocardial contractions, which leads to a decrease in the oxygen demand of the myocardium.

Verapamil reduces the muscle tone of the vascular membranes and leads to the expansion of arterioles, which weakens the resistance inside the large circle of blood flow and decreases the afterload. In addition, the drug increases coronary circulation. It inhibits AV-conduction processes and suppresses the automatic activity of the sinus node, thanks to which the drug can be used for arrhythmias of the supraventricular type.

The drug has a more pronounced effect on the conduction system (AV and sinus node), and the effect on the vessels is less pronounced. The drug improves kidney secretion. It must be remembered that the drug exacerbates the existing heart failure, and also causes AV-blockade and strong bradycardia.

[4], [5], [6]

Pharmacokinetics

The substance is almost completely absorbed by entering the gastrointestinal tract. Blood Cmax values are recorded after 1-2 hours. Synthesis with blood protein is 90%.

Subjected to rapid intrahepatic metabolism. In the case of a course of therapy, the effect of the drug is potentiated, because diclofenac and its metabolic products accumulate inside the body.

Half-life after 1-time use is 3-6 hours, and in case of prolonged use it reaches 12 hours. Excretion is carried out by the kidneys (approximately 74%).

[7], [8], [9], [10]

Dosing and administration

Regular tablets for tachycardia or angina pill are taken orally before eating, 3 times a day, in a portion of 40-80 mg. To reduce high blood pressure values, you need to use the drug 2-fold per day (daily portion in this case can reach 0.48 g).

Children under 5 years of age are required for the day to use 40-60 mg of drug.

Tablets with a prolonged type of effect with elevated blood pressure values are taken in the morning in 0.24 g portions. It is recommended to begin therapy with a reduced portion — 0.12 g 1-fold per day. Further, after 14 days, an increase in dosage is performed. It can also be increased to 0.48 g per day (2-fold intake with a 12-hour interval). If necessary, a prolonged cycle of treatment is prohibited to use more than 0.48 g of a day.

In order to stop the development of a hypertensive crisis, the drug is injected intravenously using a jet method in the amount of 5-10 mg. In the case of paroxysmal rhythm disorders, the dosage and route of administration are similar. In the absence of a result, the same portion is reintroduced after 20-30 minutes. With supporting procedures, the drug is injected intravenously through an IV (a solution of NaCl or dextrose is used). The size of a 1-fold intravenous dose for a 1–5-year-old child is 2–3 g of the substance.

[14], [15], [16], [17]

Use Verapamilla during pregnancy

At the moment there is no information about feto-and embryotoxicity of the drug. It can be used by pregnant women, but only in cases where the likely benefit is more expected than the development of complications. But at the same time it is often prescribed during pregnancy. There are both obstetric and medicinal indications for its use.

Obstetricians:

• the risk of premature onset of labor (in combination with other drugs);
• placental insufficiency;
• nephropathy developing in pregnant women.

In the case of the risk of premature delivery of the drug, use together with ginipralom; Take Verapamil should be a little earlier - for 20-30 minutes. Reviews show that the use of guinipral does not always lead to tachycardia, which eliminates the use of Verapamil, but usually it is still necessary.

Because the drug affects calcium metabolism, it is often used in situations where there is a risk of premature onset of labor. It has been found that tocolytic treatment can be performed exclusively using agents that block the Ca channels. After they are ingested, the amplitude of uterine contractions is significantly reduced (sometimes it comes to a complete cessation of this activity).

In the case of an easy stage of nephropathy, monotherapeutic use of drugs is possible, and with the development of pre-eclampsia, combined methods are used, including magnesium sulfate (it has a diuretic, anticonvulsant and antihypertensive effect), taking 80 mg of Verapamil per day and other medicines.

Therapeutic:

• arrhythmias (including supraventricular tachycardia);
• increased blood pressure values. This is one of the antihypertensive drugs used in pregnant women (and can be used for a long time), although pregnant women are rarely prescribed it as a basic antihypertensive drug;
• angina pectoris

Comments of women who used the drug during pregnancy show that it demonstrates efficacy, is tolerated without complications when used in medicinal dosages, and does not have a negative effect on the fetus.

In postpartum analysis, those women who used the drug in the first trimester, there was no increase in the incidence of congenital defects associated with its use in the infant. Also, no negative manifestations were found in the babies of those women who took Verapamil on the 2nd and 3rd trimesters.

Contraindications

Main contraindications:

• severe bradycardia;
• severe left ventricular dysfunction;
• AV-blockade grade 2–3;
• the presence of intolerance against the drug;
• reduced blood pressure values;
• SSSU.

Caution is required when used in patients with 1st degree AV-blockade, CHF, bradycardia, sinoatrial blockade, renal failure or hepatic activity, and besides in older people.

[11], [12]

Side effects Verapamilla

Often there are such side effects: constipation, nausea, weight gain, a strong decrease in blood pressure, bradycardia, redness of the skin on the face, headaches and dizziness.

More rarely, such manifestations occur: fatigue, nervousness or lethargy, rash, diarrhea, itching, gingival hyperplasia, galactorrhea, and in addition pulmonary edema, third-degree AV blockade (in the case of intravenous administration at high speed), gynecomastia, agranulocytosis , arthritis, thrombocytopenia and peripheral edema.

[13],

Overdose

Poisoning with the drug causes SA- or AV-blockade, asystole, bradycardia, or a decrease in blood pressure.

First, gastric lavage and the introduction of sorbents. If conduction disorders are noted, atropine, 10% calcium gluconate, isoprenaline and plasma substituting agents are introduced by the method. It is recommended to use a pacemaker. To increase the level of blood pressure, α-stimulants are used.

[18], [19], [20], [21]

Interactions with other drugs

Agents that slow down the activity of CYP3A4, reduce the level of verapamil; Grapefruit juice on the contrary leads to an increase in its plasma indicators.

The drug increases the plasma values of cyclosporine, quinidine with carbamazepine, ethyl alcohol, theophylline and SG. In addition, it increases the likelihood of the development of the neurotoxic effect of Li +.

The level of bioavailability of drugs increases by 50% when combined with cimetidine, which is why it is sometimes necessary to reduce its dosage.

Rifampicin significantly reduces the bioavailability of the drug.

Combined use with painkillers inhalation nature increases the likelihood of developing HF, bradycardia and AV-blockade.

The simultaneous administration of the drug together with β-blockers increases the intensity of myocardial contractility, and in addition increases the likelihood of AV-conduction disorders and the appearance of bradycardia.

When combined with α-blockers potentiates antihypertensive effect.

Negative inotropic effects are summarized in the case of administration with flekainid and disopyramide. These funds are prohibited to use for 2 days before, as well as 1 day after the introduction of Verapamil.

The drug potentiates the activity of peripheral muscle relaxants.

[22]

Storage conditions

Verapamil is required to be maintained at temperatures not higher than 25 ° C.

[23], [24], [25]

Shelf life

Verapamil is allowed to use in a period of 5 years from the date of manufacture of the pharmaceutical agent.

[26], [27]

Analogs

Analogues of the therapeutic substance are medicines Isoptin, Ryodipin, Nifedipine with Kaveril, and in addition Finoptin, Amlodipine, Nimodipine and Lekoptin with Nifedipine Retard, Gallopamil and Nicardipine.

[28], [29], [30], [31], [32], [33]

Reviews

Verapamil is often used for therapy for combined disorders (atrial fibrillation combined with supraventricular tachycardia with paroxysmal character and elevated blood pressure). Reviews of patients at the same time indicate that the drug acts quite effectively and at the same time is inexpensive.

Among the disadvantages are the development of negative symptoms - usually it is obstipation, bradycardia, and flushing of the skin of the face.