Calcium channel blockers (CCB), calcium channel antagonists or calcium antagonists are a group of medications that disrupt the movement of calcium through calcium channels. Calcium channel blockers are used as antihypertensive drugs, i.e., as medications to decrease blood pressure in patients with hypertension. CCBs are particularly effective against large vessel stiffness, one of the common causes of elevated systolic blood pressure in elderly patients. Calcium channel blockers are also frequently used to alter heart rate, to prevent peripheral and cerebral vasospasm, and to reduce chest pain caused by angina pectoris.
Antihypertensives are a class of drugs that are used to treat hypertension. Antihypertensive therapy seeks to prevent the complications of high blood pressure, such as stroke, heart failure, kidney failure and myocardial infarction. Evidence suggests that reduction of the blood pressure by 5 mmHg can decrease the risk of stroke by 34% and of ischaemic heart disease by 21%, and can reduce the likelihood of dementia, heart failure, and mortality from cardiovascular disease. There are many classes of antihypertensives, which lower blood pressure by different means. Among the most important and most widely used medications are thiazide diuretics, calcium channel blockers, ACE inhibitors, angiotensin II receptor antagonists (ARBs), and beta blockers.
Amlodipine, sold under the brand name Norvasc among others, is a calcium channel blocker medication used to treat high blood pressure, coronary artery disease (CAD) and variant angina. It is taken orally.
Diltiazem, sold under the brand name Cardizem among others, is a nondihydropyridine calcium channel blocker medication used to treat high blood pressure, angina, and certain heart arrhythmias. It may also be used in hyperthyroidism if beta blockers cannot be used. It is taken by mouth or given by injection into a vein. When given by injection, effects typically begin within a few minutes and last a few hours.
Isosorbide mononitrate, sold under many brand names, is a medication used for heart-related chest pain (angina), heart failure and esophageal spasms. It can be used both to treat and to prevent heart-related chest pain; however, it is generally less preferred than beta blockers or calcium channel blockers. It is taken by mouth.
Isradipine is a calcium channel blocker of the dihydropyridine class. It is usually prescribed for the treatment of high blood pressure in order to reduce the risk of stroke and heart attack.
Flunarizine, sold under the brand name Sibelium among others, is a drug classified as a calcium antagonist which is used for various indications. It is not available by prescription in the United States or Japan. The drug was discovered at Janssen Pharmaceutica (R14950) in 1968.
Nitrendipine is a dihydropyridine calcium channel blocker. It is used in the treatment of primary (essential) hypertension to decrease blood pressure and can reduce the cardiotoxicity of cocaine.
T-type calcium channels are low voltage activated calcium channels that become inactivated during cell membrane hyperpolarization but then open to depolarization. The entry of calcium into various cells has many different physiological responses associated with it. Within cardiac muscle cell and smooth muscle cells voltage-gated calcium channel activation initiates contraction directly by allowing the cytosolic concentration to increase. Not only are T-type calcium channels known to be present within cardiac and smooth muscle, but they also are present in many neuronal cells within the central nervous system. Different experimental studies within the 1970s allowed for the distinction of T-type calcium channels from the already well-known L-type calcium channels. The new T-type channels were much different from the L-type calcium channels due to their ability to be activated by more negative membrane potentials, had small single channel conductance, and also were unresponsive to calcium antagonist drugs that were present. These distinct calcium channels are generally located within the brain, peripheral nervous system, heart, smooth muscle, bone, and endocrine system.
The P-type calcium channel is a type of voltage-dependent calcium channel. Similar to many other high-voltage-gated calcium channels, the α1 subunit determines most of the channel's properties. The 'P' signifies cerebellar Purkinje cells, referring to the channel's initial site of discovery. P-type calcium channels play a similar role to the N-type calcium channel in neurotransmitter release at the presynaptic terminal and in neuronal integration in many neuronal types.
An adrenergic antagonist is a drug that inhibits the function of adrenergic receptors. There are five adrenergic receptors, which are divided into two groups. The first group of receptors are the beta (β) adrenergic receptors. There are β1, β2, and β3 receptors. The second group contains the alpha (α) adrenoreceptors. There are only α1 and α2 receptors. Adrenergic receptors are located near the heart, kidneys, lungs, and gastrointestinal tract. There are also α-adreno receptors that are located on vascular smooth muscle.
Cilnidipine is a calcium channel blocker. Cilnidipine is approved for use in Japan, China, India, Nepal, and Korea for hypertension.
Alpha-blockers, also known as α-blockers or α-adrenoreceptor antagonists, are a class of pharmacological agents that act as antagonists on α-adrenergic receptors (α-adrenoceptors).
Tiapamil is a calcium antagonist or calcium channel blocker. It is an experimental drug that has never been marketed.
Darodipine is an experimental calcium channel blocker that based on animal models may reduce neuronal cytoskeletal alterations during aging and in neurodegenerative disorders. Studies performed on rats have shown darodipine to have an effect on brain serotonergic systems. Darodipine increased the 5-HIAA/5-HT ratio within various parts of the brain. Darodipine has also been shown to impair memory and learning processes on mice.
Fostedil is a vasodilator acting as a calcium channel blocker which was under development for the treatment of heart conditions such as angina pectoris but was never marketed. It has antihypertensive and antiarrhythmic effects.
AH-1058 is a lipophilic antiarrhythmic calcium channel blocker synthesized by the Pharmaceutical Research Laboratories of Ajinomoto Co., Inc in Kawasaki, Japan. It is derived from cyproheptadine, a compound with known antiserotonic, antihistaminic and calcium channel blocking properties. The IUPAC name of AH-1058 is: 4-(5H-dibenzo[a,d]cyclohepten-5-ylidene)-1-[E-3-(3-methoxy-2-nitro) phenyl-2-propenyl]piperidine hydrochloride.
Calcium channel blocker toxicity is the taking of too much of the medications known as calcium channel blockers (CCBs), either by accident or on purpose. This often causes a slow heart rate and low blood pressure. This can progress to the heart stopping altogether. Some CCBs can also cause a fast heart rate as a result of the low blood pressure. Other symptoms may include nausea, vomiting, sleepiness, and shortness of breath. Symptoms usually occur in the first six hours but with some forms of the medication may not start until 24 after hours.
Lomerizine (INN) is a diphenylpiperazine class L-type and T-type calcium channel blocker. This drug is currently used clinically for the treatment of migraines, while also being used experimentally for the treatment of glaucoma and optic nerve injury.
Telmisartan/amlodipine, sold under the brand name Twynsta among others, is a fixed-dose combination medication used to treat high blood pressure. It is a combination of telmisartan, an angiotensin II receptor antagonist, and amlodipine, as the besilate, a calcium channel blocker. It is taken by mouth.
