Products
Thiazide diuretics are commercially available in tablet form. Chlorothiazide (Diuril) and the closely related and more potent hydrochlorothiazide were the first of this group to enter the market in the 1950s (Switzerland: Esidrex, 1958). However, other related thiazide-like diuretics are available (see below). In English, we speak of (thiazide diuretics) and (thiazide-like diuretics). Numerous combination preparations with hydrochlorothiazide (HCT) exist.
Structure and properties
The thiazide diuretics are derived from benzothiadiazine. They are sulfonamides.
Effects
The thiazides (ATC C03AA) have diuretic, antihypertensive, and antiedematous properties. The effects are due to inhibition of Na+/Cl– cotransporter in the early distal tubule of the kidney. This increases the excretion of both ions and water. Potassium and protons are also excreted more. The reabsorption of calcium, on the other hand, is increased.
Indications
- High blood pressure (hypertension)
- Heart failure
- Edema, for example, in heart failure, renal insufficiency and hepatic insufficiency.
- Renal diabetes insipidus
- Idiopathic hypercalcuria
- Recurrence prophylaxis of calcium-containing kidney stones.
Dosage
According to the professional information. The tablets are usually taken in the morning.
Abuse
Diuretics can be abused in competitive sports as so-called masking agents. They can mask the use of doping agents by reducing their urine concentration or promoting their excretion. Their use before or during competition is prohibited according to the doping list. Furthermore, diuretics can be misused in sports to lose weight rapidly. This is relevant for sports in which weight categories play a role.
Agents
Thiazides:
- Hydrochlorothiazide (monopreparation: Esidrex, numerous combination preparations).
Not commercially available or not available as a human drug in many countries (selection):
- Benzthiazide
- Chlorothiazide
- Mebuticide
- Polythiazide
- Trichloromethiazide (veterinary drug).
The thiazide-like diuretics do not belong to the thiazide diuretics in the strict sense because they are structurally different:
- Chlortalidone (combination preparations).
- Indapamide (Fludex, Coversum Combi, generics).
- Metolazone (Metolazone Galepharm)
Contraindications
- Hypersensitivity, including to sulfonamides.
- Anuria
- Pregnancy
Full precautions can be found in the drug label.
Adverse effects
The most common possible adverse effects include:
- Disturbances of electrolyte balance such as hypokalemia, hyponatremia, hypomagnesemia.
- Hyperuricemia (gout), increased blood lipid levels.
- Lack of appetite
- Nausea and vomiting
- Skin reactions such as hives, itching.
Thiazides can interfere with glucose tolerance and lead to high blood glucose levels.