Verapamil , sold under various trade names, is a drug used for the treatment of high blood pressure, angina (chest pain due to insufficient blood flow to the heart), and supraventricular tachycardia. It can also be used for migraine prevention and cluster headaches. This is given by mouth or by injection into blood vessels.
Common side effects include headache, low blood pressure, nausea, and constipation. Other side effects include allergic reactions and muscle aches. This is not recommended in people with slow heartbeat or heart failure. This is believed to cause problems for the baby if used during pregnancy. This is in the family of channel calcium blockers of non-dihydropyridine drugs.
Verapamil was approved for medical use in the United States in 1981. This is the List of Essential Medicines of the World Health Organization, the most effective and safe medicines needed in the health system. Verapamil is available as a generic drug. Wholesale costs in developing countries are around 1.71 to 2.70 USD per month. In the United States, a month of maintenance costs 25 to 50 USD. Long acting formulations exist.
Video Verapamil
Medical use
Verapamil is used to control ventricular levels in supraventricular tachycardia and prevention of migraine headaches. This is a class-IV antiarrhythmia and is more effective than digoxin in controlling ventricular rate. Verapamil is not listed as a first-line agent by the guidelines provided by JAMA on JNC-8. However, it may be used to treat hypertension if the patient has co-morbid atrial fibrillation or other types of arrhythmias.
Verapamil is also used intra-arterial to treat cerebral vasospasm. Verapamil is used to treat cluster headache conditions.
Maps Verapamil
Contraindications
The use of verapamil is generally avoided in people with severe left ventricular dysfunction, hypotension (systolic blood pressure less than 90 mm Hg), cardiogenic shock, and hypersensitivity to verapamil.
Side effects
The most common side effect of Verapamil is constipation (7.3%). Other side effects include: dizziness (3.3%), nausea (2.7%), low blood pressure (2.5%), and 2.2% headache. Other side effects seen in less than 2% of the population include: edema, congestive heart failure, pulmonary edema, fatigue, elevated liver enzymes, shortness of breath, low heart rate, atrioventricular block, rash and redness.
Along with other calcium channel blockers, verapamil is known to induce gingival hyperplasia.
Overdose
Acute overdose is often manifested by nausea, weakness, slow heartbeat, dizziness, low blood pressure, and abnormal heart rhythms. Plasma, serum, or blood concentrations of verapamil and norverapamil, its main active metabolites, can be measured to confirm the diagnosis of poisoning in hospitalized patients or to assist in the investigation of medicolegal against death. Blood or plasma verapamil concentrations are usually in the 50-500 μg/l range in people taking drug therapy, but may increase to 1-4 mg/l in acute overdose patients and often at 5-10 mg/I levels in fatal poisoning.
Action mechanism
The Verapamil mechanism in all cases is to block calcium channels that are voltage-dependent. In cardiac pharmacology, calcium channel blockers are considered class IV antiarrhythmic agents. Since the calcium channel is mainly concentrated in the sinoatrial and atrioventricular nodes, it can be used to decrease the conduction of impulses through the AV node, thus protecting the ventricle from the atrial tachyarrhythmias.
The calcium channel is also present in the blood vessels of smooth muscle lining. By relaxing the tone of this smooth muscle, calcium channel blockers dilate blood vessels. This has led to its use in treating high blood pressure and angina pectoris. Angina pain is caused by the deficit of oxygen supply to the heart. Calcium channel blockers such as verapamil dilate blood vessels, which increases the blood and oxygen supply to the heart. It controls chest pain, but only when used regularly. It does not stop the chest pain once it starts. Stronger vasodilators such as nitroglycerin may be needed to control the pain once it is started.
Pharmacokinetic details
More than 90% of verapamil is absorbed when administered orally, but because of a high first-pass metabolism, bioavailability is much lower (10-35%). It is 90% bound to a plasma protein and has a distribution volume of 3-5 l/kg. It takes 1 to 2 hours to reach peak plasma concentrations after oral administration. It is metabolized in the liver to at least 12 inactive metabolites (although one metabolite, norverapamil, retains 20% of vasodilation activity from the parent drug). As a metabolite, 70% are excreted in urine and 16% in the stool; 3-4% excreted unchanged in urine. This is a nonlinear dependency between plasma concentration and dose. The onset of action is 1-2 hours after an oral dose. The half-life is 5-12 hours (with a chronic dose). Not cleaned with hemodialysis. It is excreted in breast milk. Because of the potential adverse reaction in breastfeeding infants, nursing should be stopped while verapamil is given.
Verapamil has been reported to be effective in the treatment of short and long-term mania and hypomania. The addition of magnesium oxide to the verapamil treatment protocol enhances the antimanic effect. Sometimes it has been used to control the mania in pregnant patients, especially in the first three months. It does not seem teratogenic significantly. For this reason, when one wants to avoid taking valproic acid (high in teratogenicity) or lithium (which has a small but significant incidence of cardiac malformations), verapamil may be used as an alternative, although perhaps less effective.
Veterinary use
Intra-abdominal adhesion is common in rabbits after surgery. Verapamil may be given postoperatively in rabbits who have suffered trauma to the abdominal organs to prevent the formation of this adhesion. Such effects are not documented in other studies with ponies.
Usage in cell biology
Verapamil is also used in cell biology as a drug-injecting drug inhibitor such as P-glycoprotein. This is useful, as many tumor cell lines excrete the drug depletion pump, limiting the effectiveness of cytotoxic drugs or fluorescent tags. It is also used in the sorting of fluorescent cells for DNA content, as it blocks the final depletion of various DNA-binding fluorophores such as Hoechst 33342. Radioactive verapamil labeled and positron emission tomography can be used by measuring the function of P-glycoprotein.
Research
By 2015, verapamil clinical trials on diabetes are ongoing.
Trade name
Verapamil is sold under many trade names around the world.
See also
- Gallopamil
- Everyone
References
External links
- MedlinePlus DrugInfo medmaster-a684030
- "Verapamil" on Drugs.com
Source of the article : Wikipedia
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