Potassium is needed to maintain good health. When potassium level falls below 3.5 mmol/L, Hypokalemia is diagnosed. In case of extremely low level of potassium (lower than 2.5 mmol/L) the following symptoms are appeared: malaise and fatigue. This low level of potassium can lead to severe muscle weakness and paralysis; respiratory failure; intermittent muscle spasms. It is known, foods that are good sources of potassium and low in sodium may reduce the risk of high blood pressure and stroke. Potassium supplementation is also recommended as an adjuvant antihypertensive agent for patients with essential hypertension.

Quinethazone (brand name Hydromox) is a thiazide diuretic used to treat hypertension. The antihypertensive mechanism of quinethazone is less well understood. This drug was discovered in a period when only isoform carbonic anhydrases (CAs) II was known and considered physiologically/pharmacologically relevant. Recently was studied that quinethazone considerably inhibit other isozymes known nowadays to be involved in critical physiologic processes. Thiazides like quinethazone also inhibit sodium ion transport across the renal tubular epithelium through binding to the thiazide sensitive sodium-chloride transporter. Common side effects include dizziness, dry mouth, nausea, and low potassium levels. Thiazides may increase the toxicity of allopurinol, anesthetics, antineoplastic, calcium salts, diazoxide, digitalis, lithium; loop diuretics, methyldopa, nondepolarizing muscle relaxants, vitamin D; amphotericin B and anticholinergics may increase the toxicity of thiazides.