Hyperkalemia refers to high potassium levels in the blood. Potassium is an electrolyte, or charged mineral. It is important for the normal functioning of cells, particularly in cells that more actively use electrical currents, such as those of the nerves and heart. Hyperkalemia can cause muscle weakness, paralysis and heart rhythm problems. The condition has several causes, including some medications.
Drugs Affecting Kidney Filtration
The kidneys filter the blood. The filtration has a number of functions, including regulation of the level of potassium, according to "Harrison's Principles of Medicine." Some drugs raise potassium by affecting the excretion of potassium from the blood to the urine. Spironolactone is called a diuretic because it causes fluid excretion; this particular diuretic also causes the retention of potassium. Eplerenone, triamterene, amiloride and drospirenone are similar drugs.
ACE inhibitors and ARBs are medications used most frequently to lower blood pressure and also can cause hyperkalemia. NSAIDs such as ibuprofen can raise potassium in the blood, too.
Trimethoprim and pentamidine are antibiotics that can cause hyperkalemia. Finally, tacrolimus and cyclosporine used to suppress the immune system in transplant patients are also a source of high potassium.
Drugs Affecting Potassium in Cells
The concentration of potassium inside cells is higher than the concentration of potassium outside of cells, according to "Basic and Clinical Pharmacology." Some medications shift potassium from the inside of cells to the outside. Succinylcholine is one such drug. It is used during anesthesia to cause muscle relaxation. Digitalis is another, used to control the heart rhythm. Beta-blockers, which treat high blood pressure and high heart rates, have the same effect.
Potassium
Another medication responsible for hyperkalemia is potassium itself. Potassium is regularly taken by people who are on medications that cause hypokalemia, or low potassium levels. Hospital personal also measure and supplement potassium. Intravenous, or IV, potassium is more likely to raise potassium levels than oral, because intravenous potassium goes directly into the blood, whereas oral potassium is filtered through the gut.
References
- "Harrison's Principles of Internal Medicine" Anthony S. Fauci; 17th Ed. 2008
- "Basic and Clinical Pharmacology"; Katzung et al.; 11th Ed. 2009
