Nicorandil

There are at least 13 primary types of K+ channels known. In addition, within each type there are several subtypes. The best known chemical classes of potassium channel openers are nicorandil, piaacidil, and cromakalim. They are aU potent smooth muscle relaxants. PharmacologicaUy, they behave as classical vasodilators, lowering blood pressure and causiag tachycardia and fluid retention. 

Nicorandil. Nicorandil is a potassium channel opener that can lower blood pressure 21, 20, and 29 mm Hg after single oral doses of 10, 20, and 30 mg, respectively (250). There are no significant changes ia heart rate. Headache is the primary side effect. Nicorandil has potent coronary vasodilator effects. It causes sustained vasodilation of arteriolar resistance and venous capacitance blood vessels, thus reduciag cardiac preload and aftedoad. 

Typical KCO members are diazoxide, pinacidil, cromakalim, and nicorandil. KCOs activate KATP channels by binding to SUR subunits. Diazoxide and nicorandil are clinically used in treatment of PHHI and angina pectoris, respectively. 

C2H7NO 141-43-5) see Alibendol Butethamine Ciclopirox Cloxazolam Flomoxef Haloxazolam loxitalamic acid Ketanserin Levamisole Lomustine Mabuprofen Miltefosine Nicorandil Oxetacaine Phenoxybenzamine Piperazine... 

C7H15NO 622-26-4) see Piperacetazine Pipotiazine /V-(2-hydroxyethyl)-3-pyridinecarboxamide (CsH N202 6265-73-2) see Nicorandil... 

C iH5N02 59-67-6) see Aluminum nicotinate Inositol nicotinate Micinicate Nicorandil Nicotinamide Nicotinic acid benzyl ester Nikethamide Xantinol nicotinate nicotinonitrile... 

Other particular studies describing mixed compounds have been reported. Recently, special attention has been devoted to furoxan-nicorandil hybrid... 

Ikorel is a proprietary preparation of nicorandil (an anti-anginal drug). 

Despite these challenges, the area of K+ channel openers (PCOs) is emerging as an active area of drug design. Over the past 5-10 years, eight novel structural classes of PCOs have received systematic development benzopyrans (e.g., cromakalim, 7.27), cyanoguanidines (e.g., pinacidil, 7.28), thioformamides (e.g., aprikalim, 7.29), pyridyl nitrates (e.g., nicorandil, 7.30), benzothiadiazines (e.g., diazoxide, 7.31), pyrimidine sulphates (e.g., minoxidil sulphate, 7.32), tertiary carbinols, and dihydropyridines. These various classes have been subjected to analog preparation with compound optimization via structure-activity studies. 

From a clinical perspective, some of these PCO classes have attracted initial attention. Diazoxide and minoxidil have been evaluated as antihypertensive agents. These PCOs open K+ channels in the plasma membranes of vascular smooth muscle cells, causing vascular vasodilation, thereby lowering blood pressure. Cromakalim has been investigated as a smooth muscle bronchodilator for the treatment of human asthma. Nicorandil was launched in Japan in 1984 for the treatment of angina because of its perceived ability to promote vasodilation of coronary arteries. Developmental work on these and other PCOs is continuing for indications ranging from hypertension, asthma, urinary incontinence, psychosis, epilepsy, pain, and alopecia (hair loss). 

Nicorandil, diazoxide etc. (For details see chapter on Antihypertensive drugs ... 

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