Diuretics (thiazides, thiazide-like drugs and others commonly called "water pills")

Wirkungsweise Bluthochdruck Medikament Diuretika

Diuretics (water pills): How they work

Diuretics often called "water pills" (here: thiazides and thiazide-like drugs) such as hydrochlorothiazide (HCT), indapamide, xipamide and others increase the kidneys' excretion of water and table salt. When given together with other blood pressure medications, they can enhance their effect. Diuretics lower blood pressure not only by reducing the amount of fluid in the body but also in the long term, probably by decreasing the responsiveness of the receptors that cause blood vessels to constrict.

A thiazide diuretic is often the drug of choice: hydrochlorothiazide (HCT).

HCT is frequently used in multi-drug combination therapies and is available in many different combination formulations. The best-known active substance in this group is hydrochlorothiazide. A thiazide combination product is often the first choice when starting drug treatment for high blood pressure.

At the end of 2018 there was information sent to doctors (a "Red Hand" letter) about a possible association between HCT and squamous cell skin cancer. This finding is based on data from the Danish cancer registry. The German Cardiology Society warns against stopping the drug on your own. In any case, talk to your doctor.

There are, however, other diuretically active substances that can be used.

Examples include loop diuretics usually sulfonamide derivatives such as furosemide or torasemide. Loop diuretics act in the loop of Henle in the kidney (hence the name) and are very potent diuretics.

With the diuretic groups already mentioned, increased excretion of minerals can occur in addition to the increased excretion of water and salt.

Counterbalancing these are potassium-sparing diuretics such as representatives of the aldosterone antagonist group (see separate article Mineralocorticoid Receptor Antagonists = MRA), e.g. spironolactone, and the ENaC inhibitor group, e.g. amiloride.

By the way:

If you think you can get the same effect as a water pill simply by drinking less, you're mistaken and you may even harm yourself. The kidneys need a certain amount of fluid every day to work properly and to remove metabolic waste. If these wastes remain in the body because of inadequate fluid intake, kidney disease can result.

Diuretics: Side effects

Many patients find the frequent need to urinate unpleasant. Diuretics can cause low levels of sodium and potassium in the blood. This may show up as tiredness, muscle cramps, constipation, or heart rhythm disturbances. Diuretics can also raise blood lipid and sugar levels. Nevertheless, the overall effect is protective for the heart. Because the blood can become more concentrated, there may be a higher risk of thrombosis or varicose veins. Patients with elevated uric acid levels may experience more gout attacks while on diuretics. Recent studies suggest a slightly increased risk of skin cancer with thiazide therapy.

Please read the package leaflet for complete information.

Diuretics (thiazides and thiazide-like drugs) active substances:

Bemetizide, bendroflumethiazide, clopamide, chlorthalidone, hydrochlorothiazide (HCT), indapamide, mefruside, xipamide
Diuretics (thiazides/thiazide-like and loop diuretics)

Examples of active substances and approved medications:

Diuretics, mainly in combination products

Wirkstoff	Produkte
Chlortalidon	Atehexal comp Kombipräparat, Atenogamma comp Kombipräparat, Atenolol comp Kombipräparat, Hygroton, Logroton comp Kombipräparat, Prelis comp Kombipräparat, Teneretic Kombipräparat, Tenoretic Kombipräparat, TRI-Normin Kombipräparat
Furosemid	Betasemid, Diaphal, Furanthril, Furesis comp Kombipräparat, Furo, Furobeta, Furogamma, Furorese, Furosemid, Fusid, Jufurix, Lasix, Osyrol, Spiro comp Kombipräparat, Spiro-D-Tablinen
Hydrochlorothiazid	Accuzide Kombipräparat, ACE-Hemmer-Ratiopharm comp Kombipräparat, Acercomp Kombipräparat, Actelsar HCT Kombipräparat, Amiloretik, Amilorid comp Kombipräparat, Amilorid HCT Kombipräparat, Atacand plus Kombipräparat, Beloc-Zok comp Kombipräparat, Belsar plus Kombipräparat, Benalapril Plus Kombipräparat, Benazeplus Kombipräparat, Benazepril comp Kombipräparat, Beta-Turfa Kombipräparat, Bisobeta comp Kombipräparat, BisoHEXAL plus Kombipräparat, BisoLich comp Kombipräparat, Bisoplus Kombipräparat, Bisoprolol comp Kombipräparat, Bisoprolol dura, Bisoprolol HCT Kombipräparat, Bisoprolol plus Kombipräparat, Blopresid plus Kombipräparat, Blopress forte, Blopress Plus Kombipräparat, Candecor comp Kombipräparat, Candesarplus Kombipräparat, Candesartan comp Kombipräparat, Candesartan plus Kombipräparat, Candesartan/HCT Kombipräparat, Candesartancilexetil comp Kombipräparat, Candesartancilexetil plus Kombipräparat, Candesartancilexetil/HCT Kombipräparat, Capto comp Kombipräparat, Captobeta comp Kombipräparat, Captogamma HCT Kombipräparat, CaptoHEXAL Kombipräparat, Captopril Kombipräparat, Cibadrex Kombipräparat, Co-Irbenobel Kombipräparat, CoAprovel Kombipräparat, CoDiovan Kombipräparat, Concor plus Kombipräparat, Copalia HCT Kombipräparat, Cordinate plus Kombipräparat, Corvo HCT Kombipräparat, Cosamson Kombipräparat, Cotareg Kombipräparat, Cozaar comp Kombipräparat, Dafiro HCT Kombipräparat, Delix Kombipräparat, Disalunil, DIU Venostasin, Diursan, Dociteren, Dynacil comp Kombipräparat, Dynorm plus Kombipräparat, Dytide, Enabeta comp Kombipräparat, EnaHexal comp Kombipräparat, Enala-Q comp Kombipräparat, Enalagamma HCT Kombipräparat, Enalapril comp Kombipräparat, Enalapril HCT Kombipräparat, Enalapril plus Kombipräparat, Enalapril-corax comp Kombipräparat, Enaplus Kombipräparat, Eprosartan comp Kombipräparat, Esidrix, Exforge HCT Kombipräparat, Fempress plus Kombipräparat, Fortzaar Kombipräparat, Fosinorpil-Actavis comp Kombipräparat, HCT, Irbesartan plus HCT Kombipräparat, Irbesartan/Hydrochlorothiazid, Isoptin RR plus Kombipräparat, Karvezide Kombipräparat, Kinzalkomp, Lisi TAD HCT Kombipräparat, Lisibeta comp Kombipräparat, Lisigamma HCT Kombipräparat, LisiHexal comp Kombipräparat, LisiLich comp Kombipräparat, Lisinopril plus Kombipräparat, Lisiplus Kombipräparat, Lorzaar plus Kombipräparat, Losar-Q comp Kombipräparat, Losargamma HCT Kombipräparat, Losarplus Kombipräparat, Losartan comp Kombipräparat, Losartan HCT Kombipräparat, Losartan plus Kombipräparat, Mencord plus Kombipräparat, Meto-Succinat HCT Kombipräparat, Metodura comp Kombipräparat, MetoHexal comp Kombipräparat, Metoprolol comp Kombipräparat, Metoprolol HCT Kombipräparat, Metoprolol plus Kombipräparat, Metoprololsuccinat plus Kombipräparat, Metostad comp Kombipräparat, Micardis plus Kombipräparat, Moducren, Moducrin, Nephral, Olmecor HCT Kombipräparat, Olmesartan comp Kombipräparat, Olmesartan HCT Kombipräparat, Olmesartan/Hydrochlorothiazid, Olmetec plus Kombipräparat, Pritor plus Kombipräparat, Propra comp Kombipräparat, Provas comp Kombipräparat, Provas maxx, Quinaplus Kombipräparat, Quinapril comp Kombipräparat, Quinapril/Hydrochlorothiazid, Rami-Q comp Kombipräparat, Ramiclair Kombipräparat, RamiLich comp Kombipräparat, Ramiplus Kombipräparat, Ramipril beta comp Kombipräparat, Ramipril comp Kombipräparat, Ramipril HCT Kombipräparat, Ramipril plus Kombipräparat, Ramipril-Actavis comp Kombipräparat, Rasilz HCT Kombipräparat, Ratacand plus Kombipräparat, Renacor Kombipräparat, Seloken retard plus Kombipräparat, Sevikar HCT Kombipräparat, Sevikiar plus Kombipräparat, Spironothiazid, Telmisartan comp Kombipräparat, Telmisartan HCT Kombipräparat, Telmisartan plus Kombipräparat, Telmisartan/Hydrochlorothiazid, Tensobon comp Kombipräparat, Teveten plus Kombipräparat, Tolucombi Kombipräparat, Tri.-Thiazid, Triampur compositum Kombipräparat, Triamteren comp Kombipräparat, Triamteren HCT Kombipräparat, Triarese, Turfa, Valsacor comp Kombipräparat, Valsargamma HCT Kombipräparat, Valsartan comp Kombipräparat, Valsartan HCT Kombipräparat, Valsartan plus Kombipräparat, Valsartan plus Kombipräparat, Valsartan-Actavis comp Kombipräparat, Valsartan/Hydrochlorothiazid, Veratide Kombipräparat, Vocado HCT Kombipräparat, Votum plus Kombipräparat, Zofenil plus Kombipräparat
Indapamid	Bipreterax Kombipräparat, Indapagamma, Indapamid, Natrilix, Perindopril Kombipräparat, Preterax N, Rindecombi Kombipräparat
Piretanid	Arelix Kombipräparat, Betarelix, Piretanid, Ramipril/Piretanid, Ramitanid Kombipräparat
Torasemid	Toragamma, Torasemid, Torem, Unat
Xipamid	Aquaphor, Neotri, Xipagamma, Xipamid

Sources:

This article comes from BloodPressureDB – the leading app since 2011 that helps hundreds of thousands monitor their blood pressure every day. Our content is based on carefully researched, evidence-based data and is continuously updated (as of 12/2025).

Author Sabine Croci is a qualified medical assistant with many years of experience in internal medicine and cardiology practices as well as in outpatient care, and has led BloodPressureDB's specialist editorial team since 2015. Thanks to her extensive additional qualifications as a paramedic, first responder and in various therapy and emergency areas, she provides solid, practical and reliably reviewed information.

We hope you found the article helpful. For good blood pressure control, it's important to take your medications correctly. Our app BloodPressureDB will gladly remind you when to take them. It also keeps track of your medication supply and notifies you in time when you're running low. This feature is fully available in the free version as well. Get the free app now.