Nifedipine Health Dictionary

(Linn.) Lam

Synonym: Daucus visnaga Linn. Visnaga daucoides Gaertn.

Family: Umbelliferae; Apiaceae.

Habitat: Cultivated as a garden ornamental; runs wild at many places in Jammu region.

English: Khella.

Folk: Paashaanabhedi (controversial; Bergenia ligulata has been equated with the classical Paashaanabheda).

Action: Antispasmodic in renal colic, bronchial asthma, whooping cough (used by Unani physicians), vasodilator (in angina pectoris).

Key application: German Commission E approved the herb on 13 March 1986, but due to information on potential risks, its status was changed to unapproved on 15 April 1994.

Khella contains khellin (1%), vis- nagin, khellol glycoside, flavonoids, sterols, volatile oil (0.2%). Khellin and visnagin exert a powerful antispas- modic effect on the smaller bronchial muscles, the coronary arteries and on the urinary tubules. Khellin provides relief to asthmatic patients. The drug also relieves painful spasm of stone in kidney and bladder (no more used for expelling kidney stones).

Khella does not reduce blood pressure in spite of being a vasodilator.

Khellin is toxic at 100 mg. (Francis Brinker.)

Khella is used topically for vitiligo and psoriasis. The Khellin constituent is similar to the psoralen nucle

us and might be useful as a photosensi- tizer in patients with psoriasis. (Natural Medicines Comprehensive Database, 2007.)

(Several modern drugs including amiodarone, nifedipine and cromolyn have been developed from Khella.)... ammi visnaga

Calcium-channel blockers inhibit the inward ?ow of calcium through the specialised slow channels of cardiac and arterial smooth-muscle cells. By thus relaxing the smooth muscle, they have important applications in the treatment of HYPERTENSION and ANGINA PECTORIS. Various types of calcium-channel blockers are available in the United Kingdom; these di?er in their sites of action, leading to notable di?erences in their therapeutic effects. All the drugs are rapidly and completely absorbed, but extensive ?rst-pass metabolism in the liver reduces bioavailability to around one-?fth. Their hypotensive e?ect is additive with that of beta blockers (see BETA-ADRENOCEPTOR-BLOCKING DRUGS); the two should, therefore, be used together with great caution – if at all. Calcium-channel blockers are particularly useful when beta blockers are contraindicated, for example in asthmatics. However, they should be prescribed for hypertension only when THIAZIDES and beta blockers have failed, are contraindicated or not tolerated.

Verapamil, the longest-available, is used to treat angina and hypertension. It is the only calcium-channel blocker e?ective against cardiac ARRHYTHMIA and it is the drug of choice in terminating supraventricular tachycardia. It may precipitate heart failure, and cause HYPOTENSION at high doses. Nifedipine and diltiazem act more on the vessels and less on the myocardium than verapamil; they have no antiarrhythmic activity. They are used in the prophylaxis and treatment of angina, and in hypertension. Nicardipine and similar drugs act mainly on the vessels, but are valuable in the treatment of hypertension and angina. Important di?erences exist between di?erent calcium-channel blockers so their use must be carefully assessed. They should not be stopped suddenty, as this may precipitate angina. (See also HEART, DISEASES OF.)... calcium-channel blockers

(calcium antagonist) a drug that inhibits the influx of calcium ions into cardiac and smooth-muscle cells; it therefore reduces the strength of heart-muscle contraction, reduces conduction of impulses in the heart, and causes *vasodilatation. Calcium-channel blockers, which include *amlodipine, *diltiazem, *nicardipine, *nifedipine, and *verapamil, are used to treat angina and high blood pressure.... calcium-channel blocker

(perniosis) pl. n. dusky red itchy swellings that develop on the extremities in cold weather. They usually settle in two weeks but treatment with *nifedipine is helpful in severe cases. There may be a genetic predisposition to chilblains.... chilblains

n. a drug that causes widening of the blood vessels and therefore an increase in blood flow. Vasodilators are used to lower blood pressure in cases of hypertension. Coronary vasodilators, such as *glyceryl trinitrate, increase the blood flow through the heart and are used to relieve and prevent angina. Large doses of coronary vasodilators cause such side-effects as flushing of the face, severe headache, and fainting. Peripheral vasodilators affect blood flow to the limbs; they include *alpha blockers and some *calcium-channel blockers. Certain of the latter (e.g. *nifedipine) are used to treat conditions due to poor circulation, such as Raynaud’s disease and intermittent claudication.... vasodilator