Nosological classification (ICD-10)
- E23.2 Diabetes insipidus
- I10 Essential (primary) hypertension
- I15 Secondary hypertension
- I15.0 Renovascular hypertension
- I50.0 Congestive heart failure
- K76.6 Portal hypertension
- N00 Acute nephritic syndrome
- N04 Nephrotic syndrome
- N18.9 Chronic renal failure, unspecified
- N25.1 Nephrogenic diabetes insipidus
- R35 Polyuria
- R60 Edema, not elsewhere classified
- R82.9 Other and unspecified abnormalities detected by urine examination
- Y42.0 Adverse reactions during therapeutic use of glucocorticoids and their synthetic analogues
Pharmacodynamics
The primary mechanism of action of thiazide diuretics is to increase diuresis by blocking the reabsorption of sodium and chloride ions at the beginning of the renal tubules. By doing this, they increase the excretion of sodium and chlorine and, therefore, water. Excretion of other electrolytes, namely potassium and magnesium, also increases.
At maximum therapeutic doses, the natriuretic/diuretic effect of all thiazides is approximately the same. Natriuresis and diuresis occur within 2 hours and reach their maximum after about 4 hours. They also reduce carbonic anhydrase activity by increasing the excretion of bicarbonate ion, but this effect is usually mild and does not affect urine pH. Hydrochlorothiazide also has antihypertensive properties. Thiazide diuretics have no effect on normal blood pressure.
pharmachologic effect
Diuretic. The principle of action of thiazide diuretics is based on increasing diuresis through suppressing the reabsorption of Na and Cl ions in the initial sections of the tubules of the renal system, which causes increased excretion of Na, Cl ions and water. of electrolytes (Mg, K, etc.) increases
Maximum therapeutic dosages of thiazide duretics provide approximately the same natriuretic/diuretic effect. Diuresis and natriuresis are recorded after 2 hours, and the maximum effect appears after 4 hours. Thiazide diuretics are able to suppress carbonic anhydrase activity due to increased excretion of bicarbonate ions. This effect is weakly expressed and has virtually no effect on urine pH. Hydrochlorothiazide is characterized by a hypotensive effect . The active substance has no effect on normal blood pressure
Pharmacokinetics
Hydrochlorothiazide is incompletely, but rather quickly absorbed from the gastrointestinal tract. This effect lasts for 6–12 hours. After oral administration of a dose of 100 mg, Cmax in blood plasma is achieved after 1.5–2.5 hours.
At the maximum diuretic activity (approximately 4 hours after administration), the concentration of hydrochlorothiazide in the blood plasma is 2 mcg/ml. Plasma protein binding is 40%. It is excreted mainly through the kidneys (filtration and secretion) in unchanged form. T1/2 for patients with normal renal function is 6.4 hours, for patients with moderate renal failure - 11.5 hours, and for patients with creatinine Cl less than 30 ml/min - 20.7 hours.
Hydrochlorothiazide crosses the placental barrier and is excreted into breast milk.
Hypothiazide price, where to buy
The cost of the medication is relatively low and varies within small ranges depending on the amount of the active substance, pharmacy chain, and region. The average price of Hypothiazide in Russia is 100 rubles.
- Online pharmacies in RussiaRussia
- Online pharmacies in UkraineUkraine
- Online pharmacies in KazakhstanKazakhstan
ZdravCity
- Hypothiazide tablets 25 mg 20 pcs. Chinoin
96 rub. order - Hypothiazide tablets 100 mg 20 pcs. Chinoin
122 RUR order
Pharmacy Dialogue
- Hypothiazide tablets 100 mg No. 20Chinoin
RUB 131 order
- Hypothiazide tablets 25 mg No. 20Chinoin
83 RUR order
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Pharmacy24
- Hypothiazide 25 mg N20 tablets Quinoin Pharmaceutical and Chemical Products Plant Private Co. Ltd., Ugorshchina
48 UAH.order - Hypothiazide 100 mg No. 20 tablets Quinoin Pharmaceutical and Chemical Products Plant Private Co. Ltd., Ugorshchina
75 UAH order
PaniPharmacy
- Hypothiazide tablets Hypothiazide tablets. 100 mg No. 20 Hungary, Chinoin
93 UAH order
- Hypothiazide tablets Hypothiazide tablets. 25 mg No. 20 Hungary, Chinoin
53 UAH order
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Indications for the drug Hypothiazide®
arterial hypertension (used both in monotherapy and in combination with other antihypertensive drugs);
edema syndrome of various origins (chronic heart failure, nephrotic syndrome, premenstrual syndrome, acute glomerulonephritis, chronic renal failure, portal hypertension, treatment with corticosteroids);
control of polyuria, mainly in nephrogenic diabetes insipidus;
prevention of stone formation in the genitourinary tract in predisposed patients (reduction of hypercalciuria).
Contraindications
hypersensitivity to the drug or to other sulfonamides;
anuria;
severe renal (creatinine Cl - less than 30 ml/min) or liver failure;
difficult-to-control diabetes mellitus;
Addison's disease:
refractory hypokalemia, hyponatremia, hypercalcemia;
children under 3 years of age (solid dosage form).
Use with caution in case of hypokalemia, hyponatremia, hypercalcemia, in patients with coronary artery disease, with cirrhosis of the liver, gout, in the elderly, in patients suffering from lactose intolerance, when taking cardiac glycosides.
Use during pregnancy and breastfeeding
Hydrochlorothiazide penetrates the placental barrier. The use of the drug in the first trimester of pregnancy is contraindicated. In the second and third trimesters of pregnancy, the drug can be prescribed only in cases of urgent need, when the benefit to the mother outweighs the potential risk to the fetus and/or child. There is a risk of developing fetal or newborn jaundice, thrombocytopenia and other consequences.
The drug passes into breast milk; therefore, if the use of the drug is absolutely necessary, breastfeeding should be discontinued.
Side effects
Electrolyte imbalance
Hypokalemia, hypomagnesemia, hypercalcemia and hypochloremic alkalosis: dry mouth, thirst, irregular heart rhythm, mood or mental changes, muscle cramps and pain, nausea, vomiting, unusual tiredness or weakness. Hypochloremic alkalosis can cause hepatic encephalopathy or hepatic coma.
Hyponatremia: confusion, convulsions, lethargy, slow thinking, fatigue, excitability, muscle cramps.
Metabolic phenomena: hyperglycemia, glucosuria, hyperuricemia with the development of an attack of gout. Treatment with thiazides may reduce glucose tolerance, and latent diabetes mellitus may become manifest. When using high doses, serum lipid levels may increase.
From the gastrointestinal tract: cholecystitis or pancreatitis, cholestatic jaundice, diarrhea, sialadenitis, constipation, anorexia.
From the cardiovascular system: arrhythmias, orthostatic hypotension, vasculitis.
From the nervous system and sensory organs: dizziness, blurred vision (temporarily), headache, paresthesia.
From the hematopoietic organs: very rarely - leukopenia, agranulocytosis, thrombocytopenia, hemolytic anemia, aplastic anemia.
Hypersensitivity reactions: urticaria, purpura, necrotizing vasculitis, Stevens-Johnson syndrome, respiratory distress syndrome (including pneumonitis and non-cardiogenic pulmonary edema), photosensitivity, anaphylactic reactions up to shock.
Other phenomena: decreased potency, impaired renal function, interstitial nephritis.
HYPOTHIAZIDE TAB 25MG N20
Non-melanoma skin cancer and lip cancer
Two epidemiological studies based on the Danish National Cancer Registries showed an increased risk of developing non-melanoma skin cancer and lip cancer (basal cell carcinoma of the skin and squamous cell carcinoma of the skin) with increasing cumulative dose of hydrochlorothiazide.
Hydrochlorothiazide has a photosensitizing effect, which may cause the development of non-melanoma skin and lip cancer.
Patients taking hydrochlorothiazide should be informed of the risk of developing non-melanoma skin and lip cancer and the need to regularly examine the skin for new changes as well as changes in existing ones. If any suspicious skin lesions are detected, the patient should immediately consult a doctor.
Particular attention should be paid to patients who have known risk factors for skin cancer, including: skin phototypes I and II (pale and fair skin), a family history of skin cancer, a history of skin damage caused by solar or ultraviolet radiation and radiation therapy, smoking and taking drugs with photosensitizing effects.
Patients should be advised to take measures to prevent the development of skin cancer, such as limiting time in the sun and exposure to ultraviolet rays, and using appropriate sunscreens when exposed to the sun. Any suspicious skin lesions should be immediately examined, including histological examination of material obtained by biopsy of tissue at the site of the lesion. It may also be necessary to reconsider the use of hydrochlorothiazide in patients with a history of non-melanoma skin cancer and lip cancer.
Renal dysfunction
In patients with impaired renal function, hydrochlorothiazide may cause azotemia. In case of renal failure, accumulation of hydrochlorothiazide is possible.
In patients with reduced renal function, periodic monitoring of creatine clearance is necessary. If renal dysfunction progresses and/or oliguria (anuria) occurs, hydrochlorothiazide should be discontinued.
Liver dysfunction
When using thiazide diuretics in patients with impaired liver function, hepatic encephalopathy may develop. In patients with severe liver failure or hepatic encephalopathy, the use of thiazides is contraindicated. In patients with mild to moderate hepatic impairment and/or progressive liver disease, hydrochlorothiazide should be used with caution, since even slight changes in fluid and electrolyte balance and ammonium accumulation in the blood serum can cause hepatic coma. If symptoms of encephalopathy occur, diuretics should be discontinued immediately.
Water-electrolyte balance and metabolic disorders
Thiazide diuretics (including hydrochlorothiazide) can cause a decrease in the volume of circulating fluid (hypovolemia) and disturbances in water and electrolyte balance (including hypokalemia, hyponatremia, hypochloremic alkalosis). Clinical symptoms of water and electrolyte imbalance are dry mouth, thirst, weakness, lethargy, fatigue, drowsiness, anxiety, muscle pain or cramps, muscle weakness, marked decrease in blood pressure, oliguria, tachycardia, arrhythmia and gastrointestinal disorders ( such as nausea and vomiting). In patients receiving hydrochlorothiazide therapy (especially with long-term course treatment), clinical symptoms of water and electrolyte imbalance should be identified and blood electrolyte levels should be regularly monitored.
Sodium
All diuretics can cause hyponatremia, sometimes leading to severe complications. Hyponatremia and hypovolemia can lead to dehydration and orthostatic hypotension. A concomitant decrease in chlorine ions can lead to secondary compensatory metabolic alkalosis, but the frequency and severity of this effect are insignificant. It is recommended to determine the content of sodium ions in the blood plasma before starting treatment and regularly monitor this indicator while taking hydrochlorothiazide.
Potassium
When using thiazide and thiazide-like diuretics, there is a risk of a sharp decrease in the potassium content in the blood plasma and the development of hypokalemia (potassium concentration less than 3.4 mmol/l). Hypokalemia increases the risk of developing heart rhythm disturbances (including severe arrhythmias) and enhances the toxic effect of cardiac glycosides. In addition, hypokalemia (as well as bradycardia) is a condition that contributes to the development of polymorphic ventricular tachycardia of the “pirouette” type, which can be fatal.
Hypokalemia poses the greatest danger to the following groups of patients: elderly people, patients simultaneously receiving therapy with antiarrhythmic and non-antiarrhythmic drugs that can cause polymorphic ventricular tachycardia of the "pirouette" type or increase the duration of the QT interval on the ECG, patients with impaired liver function, coronary heart disease , chronic heart failure. In addition, patients with an increased QT interval are at increased risk. It does not matter whether this increase in the interval is caused by congenital causes or the effect of drugs.
In all the cases described above, it is necessary to avoid the risk of developing hypokalemia and regularly monitor the potassium content in the blood plasma. The first measurement of the content of potassium ions in the blood must be carried out within the first week from the start of treatment. If hypokalemia occurs, appropriate treatment should be prescribed. Hypokalemia can be corrected by using potassium-containing medications or eating foods rich in potassium (dried fruits, fruits, vegetables).
Calcium
Thiazide diuretics may reduce the excretion of calcium ions by the kidneys, leading to a slight and temporary increase in plasma calcium levels. In some patients, with long-term use of thiazide diuretics, pathological changes in the parathyroid glands were observed with hypercalcemia and hyperphosphatemia, but without the typical complications of hyperparathyroidism (nephrolithiasis, decreased bone mineral density, peptic ulcer). Severe hypercalcemia may be a manifestation of previously undiagnosed hyperparathyroidism.
Because of their effect on calcium metabolism, thiazides may interfere with laboratory parameters of parathyroid function. Thiazide diuretics (including hydrochlorothiazide) should be discontinued before testing parathyroid function.
Magnesium
Thiazides have been found to increase renal excretion of magnesium, which can lead to hypomagnesemia. The clinical significance of hypomagnesemia remains unclear.
Glucose
Treatment with thiazide diuretics may impair glucose tolerance. When using hydrochlorothiazide in patients with manifest or latent diabetes mellitus, it is necessary to regularly monitor the concentration of glucose in the blood. Dosage adjustments of hypoglycemic medications may be necessary.
Uric acid
In patients with gout, the frequency of attacks may increase or the course of gout may worsen. Careful monitoring of patients with gout and impaired uric acid metabolism (hyperuricemia) is necessary.
Lipids
When using hydrochlorothiazide, the concentration of cholesterol and triglycerides in the blood plasma may increase.
Acute myopia/secondary angle-closure glaucoma
Hydrochlorothiazide can cause an idiosyncratic reaction, leading to the development of acute myopia and an acute attack of secondary angle-closure glaucoma. Symptoms include: sudden loss of visual acuity or eye pain, usually occurring within hours to weeks of starting hydrochlorothiazide therapy. If left untreated, acute angle-closure glaucoma can lead to irreversible vision loss. If symptoms occur, you should stop taking hydrochlorothiazide as soon as possible. If intraocular pressure remains uncontrolled, emergency medical treatment or surgery may be required. Risk factors for the development of acute angle-closure glaucoma are: a history of an allergic reaction to sulfonamides or penicillin.
Immune system disorders
There are reports that thiazide diuretics (including hydrochlorothiazide) may cause exacerbation or progression of systemic lupus erythematosus, as well as lupus-like reactions.
In patients receiving thiazide diuretics, hypersensitivity reactions may occur even in the absence of a history of allergic reactions or bronchial asthma.
Photosensitivity
Cases of photosensitivity reactions have been reported when taking thiazide diuretics. If photosensitivity occurs while taking hydrochlorothiazide, treatment should be discontinued.
Ethanol (alcohol)
During treatment with hydrochlorothiazide, it is not recommended to drink alcoholic beverages, since ethanol enhances the antihypertensive effect of thiazide diuretics.
Other
In patients with severe atherosclerosis of the cerebral and coronary arteries, hydrochlorothiazide should be used with extreme caution.
Thiazide diuretics can reduce the amount of iodine bound to plasma proteins without causing signs of thyroid dysfunction.
Impact on the ability to drive vehicles and machinery
At the beginning of using the drug, a decrease in blood pressure is possible, which can affect activities that require increased attention, coordination and speed of decision-making. Therefore, care must be taken when performing work that requires increased attention and when driving, especially at the beginning of treatment and when increasing the dose of hydrochlorothiazide.
Interaction
The simultaneous use of the drug with lithium salts should be avoided (renal clearance of lithium decreases and its toxicity increases).
Use with caution with the following drugs:
- antihypertensive drugs (their effect is potentiated, there may be a need for dose adjustment);
- cardiac glycosides (hypokalemia and hypomagnesemia associated with the action of thiazide diuretics can increase the toxicity of digitalis);
- amiodarone (its use simultaneously with thiazide diuretics may lead to an increased risk of arrhythmias associated with hypokalemia);
- hypoglycemic agents for oral administration (their effectiveness decreases, hyperglycemia may develop);
- corticosteroid drugs, calcitonin (increase the degree of potassium excretion);
- NSAIDs (can weaken the diuretic and hypotensive effects of thiazides);
- non-depolarizing muscle relaxants (their effect may be enhanced);
- amantadine (the clearance of amantadine may be reduced by hydrochlorothiazide, which leads to an increase in plasma concentrations of amantadine and possible toxicity);
- cholestyramine, which reduces the absorption of hydrochlorothiazide;
- ethanol, barbiturates and narcotic analgesics, which enhance the effect of orthostatic hypotension.
Effect of the drug on laboratory test data
Thiazides may reduce plasma levels of protein-bound iodine.
Before testing the function of the parathyroid glands, thiazides should be discontinued. Serum bilirubin concentrations may be increased.
Hypothiazide analogs
Level 4 ATC code matches:
Dichlorothiazide
Hydrochlorothiazide
Structural analogues:
- Hydrochlorothiazide-SAR;
- Hydrochlorothiazide.
Medicines with similar pharmacological effects (diuretics):
- Veroshpiron;
- Diuver;
- Indapamide;
- Torasemide;
- Arifon;
- Spironolactone;
- Inspra;
- Lasix;
- Furosemide.
Directions for use and doses
Inside, after eating.
The dosage must be selected individually. With constant medical supervision, the minimum effective dose is established.
Due to the increased loss of potassium and magnesium ions during treatment (serum potassium levels may decrease below 3.0 mmol/l), there is a need to replace potassium and magnesium.
For adults. As an antihypertensive agent, the usual initial daily dose is 25–50 mg once, as monotherapy or in combination with other antihypertensive agents. For some patients, an initial dose of 12.5 mg is sufficient, either as monotherapy or in combination. It is necessary to use the minimum effective dose, not exceeding 100 mg/day. If Hypothiazide is combined with other antihypertensive drugs, it may be necessary to reduce the dose of the other drug in order to prevent an excessive decrease in blood pressure.
The hypotensive effect appears within 3–4 days, but it may take up to 3–4 weeks to achieve optimal effect. After completion of treatment, the hypotensive effect persists for 1 week.
Edema syndrome of various origins. The usual starting dose for the treatment of edema is 25–100 mg of the drug once a day or once every 2 days. Depending on the clinical response, the dose may be reduced to 25–50 mg once a day or once every 2 days. In some severe cases, doses up to 200 mg/day may be required at the beginning of treatment.
For premenstrual syndrome, the usual dose is 25 mg/day and is used from the onset of symptoms to the onset of menstruation.
For nephrogenic diabetes insipidus, the usual daily dose of 50–150 mg (in divided doses) is recommended.
For children. Doses should be set based on the child’s body weight. Usual pediatric daily doses are 1–2 mg/kg or 30–60 mg/m2 body surface area, given once daily. The total daily dose for children aged 3 to 12 years is 37.5–100 mg.
Reviews about Hypothiazide
The medication is often prescribed for diseases of the heart and vascular system, accompanied by edema syndrome. Patients note a mild diuretic effect of the drug if the dosages specified by the doctor are observed. The edema syndrome is relieved gradually, without washing away the necessary microelements from the body.
Reviews about Hypothiazide for weight loss are mixed. Weight does indeed decrease, but only due to lost fluid. The kilograms return after water enters the body. The medication does not have any effect on fat and muscle tissue, so the use of Hypothiazide for weight loss is inappropriate, and in some cases can be harmful to health (loss of microelements, dehydration, etc.)
Overdose
The most noticeable manifestation of hydrochlorothiazide overdose is acute loss of fluid and electrolytes, manifested by the following signs and symptoms:
Cardiovascular: tachycardia, decreased blood pressure, shock.
Neuromuscular: weakness, confusion, dizziness and calf muscle spasms, paresthesia, disturbances of consciousness, fatigue.
Gastrointestinal: nausea, vomiting, thirst.
Renal: polyuria, oliguria or anuria (due to hemoconcentration).
Laboratory indicators: hypokalemia, hyponatremia, hypochloremia, alkalosis, increased levels of urea nitrogen in the blood (especially in patients with renal failure).
Treatment: There is no specific antidote for an overdose of hydrochlorothiazide.
Induction of vomiting and gastric lavage may be ways to eliminate the drug.
Absorption of the drug can be reduced by administering activated carbon. In case of decreased blood pressure or shock, blood volume and electrolytes (potassium, sodium) should be replaced.
Monitor fluid and electrolyte balance (especially serum potassium levels) and renal function until normal values are established.
special instructions
During long-term treatment, it is necessary to carefully monitor the clinical symptoms of water-electrolyte imbalance, primarily in patients at high risk: patients with diseases of the cardiovascular system and impaired liver function; in case of severe vomiting or when signs of water and electrolyte imbalance appear, such as dry mouth, thirst, weakness, lethargy, drowsiness, anxiety, muscle pain or cramps, muscle weakness, hypotension, oliguria, tachycardia, gastrointestinal complaints.
Hypokalemia can be avoided by using potassium-containing drugs or foods rich in potassium (fruits, vegetables), especially in the case of increased potassium loss (increased diuresis, prolonged treatment) or concomitant treatment with digitalis glycosides or corticosteroid drugs.
Thiazides have been shown to increase urinary excretion of magnesium; this may lead to hypomagnesemia.
With reduced renal function, monitoring of creatinine clearance is necessary. In patients with impaired renal function, the drug may cause azotemia, and cumulative effects may develop. If renal dysfunction is obvious, discontinuation of the drug should be considered when oliguria occurs.
In patients with impaired liver function or with progressive liver diseases, thiazides are prescribed with caution, since a slight change in water and electrolyte balance, as well as serum ammonium levels, can cause hepatic coma.
In cases of severe cerebral and coronary sclerosis, the administration of the drug requires special caution.
Treatment with thiazide drugs may impair glucose tolerance. During a long course of treatment for manifest and latent diabetes mellitus, systematic monitoring of carbohydrate metabolism is necessary; It may be necessary to change the dose of hypoglycemic drugs. Increased monitoring of patients with impaired uric acid metabolism is required.
Alcohol, barbiturates, and narcotic analgesics enhance the orthostatic hypotensive effect of thiazide diuretics.
With long-term therapy, in rare cases, pathological changes in the parathyroid glands were observed, accompanied by hypercalcemia and hypophosphatemia. Thiazides can reduce the amount of iodine bound to serum proteins without causing signs of thyroid dysfunction.
In patients suffering from lactose intolerance, gastrointestinal complaints may occur due to the presence of lactose in the tablets: Hypothiazide® 25 mg tablets contain 63 mg of lactose, Hypothiazide® 100 mg - 39 mg of lactose.
Impact on the ability to drive a car and perform work that requires increased attention. In the initial stage of using the drug (the duration of this period is determined individually), it is forbidden to drive a car or perform work that requires increased attention.
Hypothiazid®
Non-melanoma skin cancer, lip cancer
Two epidemiological studies based on the Danish National Cancer Registries showed an increased risk of developing non-melanoma skin cancer and lip cancer (basal cell carcinoma of the skin and squamous cell carcinoma of the skin) with increasing cumulative dose of hydrochlorothiazide.
Hydrochlorothiazide has a photosensitizing effect, which may cause the development of non-melanoma skin and lip cancer.
Patients taking hydrochlorothiazide should be informed of the risk of developing non-melanoma skin and lip cancer and the need to regularly examine the skin for new changes as well as changes in existing ones. If any suspicious skin lesions are detected, the patient should immediately consult a doctor.
Particular attention should be paid to patients who have known risk factors for skin cancer, including: skin phototypes I and II (pale and fair skin), a family history of skin cancer, a history of skin damage caused by solar or ultraviolet radiation and radiation therapy, smoking and taking drugs with photosensitizing effects.
Patients should be advised to take measures to prevent the development of skin cancer, such as limiting time in the sun and exposure to ultraviolet rays, and using appropriate sunscreens when exposed to the sun.
Any suspicious skin lesions should be immediately examined, including histological examination of material obtained by biopsy of tissue at the site of the lesion. It may also be necessary to reconsider the use of hydrochlorothiazide in patients with a history of non-melanoma skin cancer and lip cancer.
Renal dysfunction
In patients with impaired renal function, hydrochlorothiazide may cause azothermia. In case of renal failure, accumulation of hydrochlorothiazide is possible.
In patients with reduced renal function, periodic monitoring of creatine clearance is necessary. If renal dysfunction progresses and/or oliguria (anuria) occurs, hydrochlorothiazide should be discontinued.
Liver dysfunction
When using thiazide diuretics in patients with impaired liver function, hepatic encephalopathy may develop. In patients with severe liver failure or hepatic encephalopathy, the use of thiazides is contraindicated.
In patients with mild to moderate hepatic impairment and/or progressive liver disease, hydrochlorothiazide should be used with caution, since even slight changes in fluid and electrolyte balance and serum ammonium accumulation can cause hepatic coma. If symptoms of encephalopathy occur, diuretics should be discontinued immediately.
Water-electrolyte balance and metabolic disorders
Thiazide diuretics (including hydrochlorothiazide) can cause a decrease in the volume of circulating fluid (hypovolemia) and disturbances in water and electrolyte balance (including hypokalemia, hyponatremia, hypochloremic alkalosis).
Clinical symptoms of water and electrolyte imbalance are dry mouth, thirst, weakness, lethargy, fatigue, drowsiness, anxiety, muscle pain or cramps, muscle weakness, marked decrease in blood pressure, oliguria, tachycardia, arrhythmia and gastrointestinal disorders ( such as nausea and vomiting).
In patients receiving hydrochlorothiazide therapy (especially with long-term course treatment), clinical symptoms of water-electrolyte imbalance should be identified and blood electrolyte levels should be regularly monitored.
Sodium
All diuretics can cause hyponatremia, sometimes leading to severe complications. Hyponatremia and hypovolemia can lead to dehydration and orthostatic hypotension. A concomitant decrease in chlorine ions can lead to secondary compensatory metabolic alkalosis, but the frequency and severity of this effect are insignificant. It is recommended to determine the content of sodium ions in the blood plasma before starting treatment and regularly monitor this indicator while taking hydrochlorothiazide.
Potassium
When using thiazide and thiazide-like diuretics, there is a risk of a sharp decrease in the potassium content in the blood plasma and the development of hypokalemia (potassium concentration less than 3.4 mmol/l).
Hypokalemia increases the risk of developing heart rhythm disturbances (including severe arrhythmias) and enhances the toxic effect of cardiac glycosides. In addition, hypokalemia (as well as bradycardia) is a condition that contributes to the development of polymorphic ventricular tachycardia of the “pirouette” type, which can be fatal.
Hypokalemia poses the greatest danger to the following groups of patients: elderly people, patients simultaneously receiving therapy with antiarrhythmic and non-antiarrhythmic drugs that can cause polymorphic ventricular tachycardia of the "pirouette" type or increase the duration of the QT interval on the ECG, patients with impaired liver function, coronary heart disease , chronic heart failure.
In addition, patients with an increased QT interval are at increased risk. It does not matter whether this increase in the interval is caused by congenital causes or the effect of drugs.
In all the cases described above, it is necessary to avoid the risk of developing hypokalemia and regularly monitor the potassium content in the blood plasma. The first measurement of the content of potassium ions in the blood must be carried out within the first week from the start of treatment. If hypokalemia occurs, appropriate treatment should be prescribed.
Hypokalemia can be corrected by using potassium-containing medications or eating foods rich in potassium (dried fruits, fruits, vegetables).
Calcium
Thiazide diuretics may reduce the excretion of calcium ions by the kidneys, leading to a slight and temporary increase in plasma calcium levels. In some patients, with long-term use of thiazide diuretics, pathological changes in the parathyroid glands with hypercalcemia and hyperphosphatemia were observed, but without the typical complications of hyperparathyroidism (nephrolithiasis, decreased bone mineral density, peptic ulcer).
Severe hypercalcemia may be a manifestation of previously undiagnosed hyperparathyroidism.
Because of their effect on calcium metabolism, thiazides may interfere with laboratory parameters of parathyroid function. Thiazide diuretics (including hydrochlorothiazide) should be discontinued before testing parathyroid function.
Magnesium
Thiazides have been found to increase renal excretion of magnesium, which can lead to hypomagnesemia. The clinical significance of hypomagnesemia remains unclear.
Glucose
Treatment with thiazide diuretics may impair glucose tolerance. When using hydrochlorothiazide in patients with manifest or latent diabetes mellitus, it is necessary to regularly monitor the concentration of glucose in the blood. Dosage adjustments of hypoglycemic medications may be necessary.
Uric acid
In patients with gout, the frequency of attacks may increase or the course of gout may worsen. Careful monitoring of patients with gout and impaired uric acid metabolism (hyperuricemia) is necessary.
Lipids
When using hydrochlorothiazide, the concentration of cholesterol and triglycerides in the blood plasma may increase.
Acute myopia/secondary angle-closure glaucoma
Hydrochlorothiazide can cause an idiosyncratic reaction, leading to the development of acute myopia and an acute attack of secondary angle-closure glaucoma. Symptoms include: sudden loss of visual acuity or eye pain, usually occurring within hours to weeks of starting hydrochlorothiazide therapy. If left untreated, acute angle-closure glaucoma can lead to irreversible vision loss. If symptoms occur, you should stop taking hydrochlorothiazide as soon as possible. If intraocular pressure remains uncontrolled, emergency medical treatment or surgery may be required.
Risk factors for the development of acute angle-closure glaucoma are: a history of an allergic reaction to sulfonamides or penicillin.
Immune system disorders
There are reports that thiazide diuretics (including hydrochlorothiazide) may cause exacerbation or progression of systemic lupus erythematosus, as well as lupus-like reactions.
In patients receiving thiazide diuretics, hypersensitivity reactions may occur even in the absence of a history of allergic reactions or bronchial asthma.
Photosensitivity
Cases of photosensitivity reactions have been reported when taking thiazide diuretics. If photosensitivity occurs while taking hydrochlorothiazide, treatment should be discontinued.
Ethanol (alcohol)
During treatment with hydrochlorothiazide, it is not recommended to drink alcoholic beverages, because ethanol enhances the antihypertensive effect of thiazide diuretics.
Other
In patients with severe atherosclerosis of the cerebral and coronary arteries, hydrochlorothiazide should be used with extreme caution.
Thiazide diuretics can reduce the amount of iodine bound to plasma proteins without causing signs of thyroid dysfunction.
