Drug class
Thiazide diuretic
Finished products (selection)
Disalunil ® (D)
Esidrex ® (A, CH)
Effect
Hydrochlorothiazide is a benzothiadiazine derivative that, like other diuretics in this group primarily causes more excretion of electrolytes and secondarily by increasing the osmotic water bound to the flow of urine. It is used for the treatment of cardiac, liver or kidney disease caused water retention (cardiac, hepatic, nephrogenic edema), arterial hypertension, short-term (few days) treatment of severe fluid retention in the legs caused by chronic venous insufficiency, while physical therapy,chronic heart failure and diabetes insipidus, when other medicinal measures are not in question.
Mechanism of action
Thiazides and thiazide-analog derivatives inhibit the reabsorption of sodium predominantly in the distal convoluted tubule through inhibition of the Na / Cl cotransporter, with a maximum of about 15% of the glomerular filtered sodium can be excreted. The extent of chloride secretion is about the excretion of sodium.
By thiazide diuretics increases the excretion of potassium, which is essentially determined by the potassium secretion in the distal tubule and collecting duct (increased exchange between sodium and potassium ions).
By high doses of thiazide diuretics may be excreted bicarbonate increased due to inhibition of carbonic anhydrase, making the urine alkaline.
Hydrochlorothiazide is a benzothiadiazine derivative that, like other diuretics in this group primarily causes more excretion of electrolytes and secondarily by increasing the osmotic water bound to the flow of urine.
Acidosis or alkalosis by the saluretic and diuretic effect of hydrochlorothiazide is not significantly affected.
The glomerular filtration rate is reduced initially mild.
Can during long term treatment with hydrochlorothiazide reduces the excretion of calcium through the kidneys, so that a resulting hypercalcemia.
Hydrochlorothiazide in hypertensive patients has a blood pressure-lowering effect.The mechanism has not yet been sufficiently clarified. Discussed, among other things, that the gefäßtonusmindernde effect of thiazide diuretics by decreasing the sodium concentration in the vessel wall and thus a decreased responsiveness to noradrenaline is due.
In chronic renal failure patients (creatinine clearance below 30 ml / min and / or serum creatinine above 1.8 mg/100 ml), hydrochlorothiazide is practically ineffective.
In patients with renal and ADH-sensitive diabetes insipidus, antidiuretic effect of hydrochlorothiazide.
Contraindications (contraindications)
The following are absolute counter indications (situations in which the drug should be administered in any case) and relative contraindications (situations in which the drug should be administered with caution) listed. For more information or answers to your questions please use the forum or ask your doctor or pharmacist.
Absolute contraindications
- Hypersensitivity to hydrochlorothiazide;
- Severe renal impairment (renal failure with oliguria or anuria, creatinine clearance <30 ml / min and / or serum creatinine> 1.8 mg/100 ml);
- Acute glomerulonephritis;
- Severe liver function disorders, e.g. Hepatic coma and Praecoma;
- Hypokalemia;
- Hyponatremia;
- Hypovolemia;
- Hypercalcaemia;
- Symptomatic hyperuricemia (gout or a history of uric acid stones), gout;
- States with increased potassium loss, e.g. Nephropathies with salt depletion and prerenal (cardiogenic), renal dysfunction
- Pregnancy;
- Breast-feeding.
Relative contraindications
Special watch for:
- Hypotension;
- Cerebro vascular disease;
- Coronary heart disease;
- Overt or latent diabetes mellitus;
- Renal insufficiency with serum creatinine 1.1 to 1.8 mg/100 ml and slight limitation of creatinine clearance (30-60 ml / min);
- Impaired liver function.
Side effects (adverse reactions)
This is a complete list of the known side effects, for more information or answers to your questions please use the forum or ask your doctor or pharmacist.
Adverse effects, without specifying the frequency
- ECG changes, increased sensitivity to glycoside
- With the appropriate predisposition: gout attacks
- Worsening of preexisting myopia
- Development or worsening of an existing metabolic alkalosis
Hypokalemia in a row:
- Fatigue
- Drowsiness
- Muscle weakness
- Paresthesia
- Paresis
- Apathy
- Adynamia smooth muscle with constipation, bloating
- Heart rhythm disturbances
In severe hypokalaemia:
- Paralytic ileus
- Loss of consciousness to coma
Very common adverse reactions (> 1 / 10)
- Heart rhythm disturbances
- Hyperuricemia (which can cause gout in susceptible patients)
- Metabolism in healthy individuals, latent or manifest diabetes, hypokalemia: hyperglycemia, glucosuria
- Manifestation of a latent, overt diabetes mellitus, exacerbation of
- Increase in serum lipids: cholesterol, triglycerides
Long-term continuous use: cause fluid and electrolyte balance, particularly:
- Hypokalemia
- Hyponatremia
- Hypochloremia
- Hypercalcemia
- Hypermagnesemia
Common adverse reactions (> 1 / 100)
- Thrombocytopenia
- Hypomagnesemia
- Reversible increases in serum uric substances: creatinine, urea
- Hyperamylasemia
- Pancreatitis
- With pre-existing cholelithiasis, acute cholecystitis
- Loss of appetite
- Nausea
- Vomiting
- Diarrhoea
- Pain and cramps in the abdomen.
Due to hyponatremia / hypovolemia:
- Dry mouth, thirst
- Weakness, dizziness
- Muscle pain, cramps (for example, leg cramps)
- Headaches
- Nervousness
- Palpitations
- Hypotension
- Orthostatic dysregulation
- Hemoconcentration
Uncommon adverse reactions (> 1 / 1000)
- Hypersensitivity reactions
- Allergic skin reactions, e.g. Itching, erythema, photo allergic rash, purpura, urticaria
- Drug-fever
- Jaundice
- Interstitial nephritis
- Vasculitis (necrotizing in individual cases)
- Leukopenia
- Erectile Dysfunction
- Mild visual disturbances (eg blurred vision, xanthopsia)
- Limiting the formation of tears
- Acute interstitial pneumonia
- Respiratory distress syndrome (respiratory distress)
When excessive diuresis with hemoconcentration:
- Convulsions;
- Dizziness;
- Confusion;
- Circulatory collapse;
- Acute renal failure;
- V.a. in old age and preexisting venous disease: thrombosis, embolism.
Rare adverse reactions (> 1 / 10000)
- Headaches
- Dizziness
- Insomnia
- Depression
- Paresthesia
- Constipation
- Intrahepatic cholestasis, jaundice
Very rare adverse reactions (<1 / 10000)
- Sudden onset of pulmonary edema with shock symptoms (suspected allergic origin)
- Toxic epidermal necrolysis
- Cutaneous lupus erythematosus (also its reactivation)
- Lupus-like reactions
- Aplastic anemia, hemolytic
- While taking methyldopa: immunhämolytische anemia due to antibody formation hydrochlorothiazide
- Agranulocytosis
- Bone marrow depression
- Hypochloraemic alkalosis
