A mineral needed to help maintain normal heart rhythm, regulate the body’s water balance, conduct nerve impulses, and contract muscles. Dietary sources of potassium include lean meat, whole grains, green leafy vegetables, beans, and various fruits, such as apricots, dates, and peaches.
A low level of potassium in the blood is known as hypokalaemia. It is usually a result of loss of fluids through diarrhoea and/or vomiting, and causes fatigue, drowsiness, dizziness, and muscle weakness. In more severe cases, there may be abnormal heart rhythms and muscle paralysis.
Excess potassium in the blood is known as hyperkalaemia and is much less common than hypokalaemia. It may be due to excessive intake of potassium supplements, severe kidney failure, Addison’s disease, or prolonged treatment with potassium-sparing in a similar way to nitrates, and widens both arteries and veins. Possible side effects include flushing, nausea, vomiting, and dizziness.
A metal which, on account of its great a?nity for other substances, is not found in a pure state in nature. Its salts are widely used in medicine but, as their action depends in general not on their metallic radical but upon the acid with which it is combined, their uses vary greatly and are described elsewhere. All salts of potassium depress the heart’s action as a result of action by the potassium ion.
n. a mineral element and an important constituent of the human body. It is the main base ion of intracellular fluid. Together with *sodium, it helps to maintain the electrical potential of the nervous system and is thus essential for the functioning of nerve and muscle. Normal blood levels are between 3.5 and 5 mmols/litre. High concentrations occur particularly in kidney failure and may lead to *arrhythmia and finally to cardiac arrest. Low values result from fluid loss, e.g. due to vomiting or diarrhoea, and this may lead to general muscle paralysis. A diet high in potassium can help to lower blood pressure; good sources are fruit, vegetables, and wholegrain cereals. Symbol: K.
any one of a class of drugs that enhance the movement of potassium ions through the *ion channels in cell membranes. In the case of smooth muscle cells, such as those in the walls of arteries, their sensitivity to the normal stimuli to contract is reduced. The result is relaxation of the muscle fibres and widening of the arteries. Potassium-channel activators are used for improving the blood supply to the heart muscle in angina pectoris. Possible side-effects include headache, flushing, vomiting, dizziness, and weakness. A currently available member of the class is nicorandil.... potassium-channel activator
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