Product Overview
[Drug Name]
Generic Name: Hydrochlorothiazide Tablets
Trade Name: Common Medicine
English Name: Hydrochlorothiazide Tablets
Chinese Pinyin: Qing Lv Sai Qin Pian
[Ingredients]
Hydrochlorothiazide.
[Properties]
This product is a white tablet.
[Indications]
1. Edema Disorders: Excretes excess sodium and water from the body, reduces extracellular fluid volume, and eliminates edema. Common indications include congestive heart failure, ascites due to cirrhosis, nephrotic syndrome, edema due to acute and chronic nephritis, early-stage chronic renal failure, and sodium and water retention caused by corticosteroid and estrogen therapy.
2. Hypertension: Can be used alone or in combination with other antihypertensive drugs, primarily for the treatment of essential hypertension.
3. Central or nephrogenic diabetes insipidus.
4. Nephrolithiasis: Primarily used to prevent stones formed by calcium salts.
[Dosage and Administration]
1. Oral use, adult dosage. ① For the treatment of edema, take 25-50 mg once or twice daily, or every other day, or for 3-5 consecutive days per week. ② For the treatment of hypertension, take 25-100 mg daily, divided into 1-2 doses, and adjust the dose based on the antihypertensive effect.
2. The usual oral dose for children: 1-2 mg/kg per body weight or 30-60 mg/m² per body surface area, divided into 1-2 doses per day, and adjust the dose based on the therapeutic effect. The dose for infants under 6 months can reach 3 mg/kg per day.
[Adverse Reactions]
Most adverse reactions are related to the dose and duration of treatment. 1. Side effects due to fluid and electrolyte imbalances are common. Hypokalemia is more likely to occur due to the potassium-excreting effect of thiazide diuretics. Long-term potassium depletion can damage the renal tubules. Severe potassium depletion can cause vacuolar changes in the renal tubular epithelium and ectopic heart rates such as severe tachyarrhythmias. In cases of hypochloremic alkalosis or hypochloremic and hypokalemic alkalosis, thiazides, especially hydrochlorothiazide, often significantly increase chloride excretion. Furthermore, hyponatremia is not uncommon, leading to central nervous system symptoms and worsening renal damage. Dehydration, resulting in reduced blood volume and renal blood flow, can also cause a decrease in glomerular filtration rate. Common clinical reactions to the above-mentioned water and electrolyte disorders include dry mouth, thirst, muscle cramps, nausea, vomiting, and extreme fatigue and weakness. 2. Hyperglycemia. This drug can impair glucose tolerance and increase blood sugar, which may be related to the inhibition of insulin release. 3. Hyperuricemia. It interferes with the excretion of uric acid by the renal tubules and can, in rare cases, induce gout attacks. Since joint pain is usually absent, hyperuricemia is easily overlooked. 4. Allergic reactions, such as rashes and urticaria, are relatively rare. 5. Leukopenia or deficiency, thrombocytopenic purpura, etc. are also rare. 6. Other rare conditions include cholecystitis, pancreatitis, sexual dysfunction, photosensitivity, and color vision impairment.
[Contraindications]
Use with caution in infants with jaundice, as this drug may increase blood bilirubin. Elderly individuals are more susceptible to hypotension, electrolyte imbalances, and renal impairment when using this drug.
[Precautions]
1. Cross-sensitivity: Cross-reactions with sulfonamides, furosemide, bumetanide, and carbonic anhydrase inhibitors. 2. Interference with diagnosis: May cause impaired glucose tolerance, increased blood glucose, urine glucose, blood bilirubin, blood calcium, blood uric acid, blood cholesterol, blood triglycerides, and low-density lipoprotein cholesterol, and decreased blood magnesium, potassium, sodium, and urine calcium. 3. Use with caution in the following situations: ① Patients with anuria or severe renal impairment, as this class of drugs is less effective, and high doses can lead to drug accumulation and increased toxicity; ② Diabetes; ③ Hyperuricemia or a history of gout; ④ Severe liver damage, as fluid and electrolyte imbalances can induce hepatic coma; ⑤ Hypercalcemia; ⑥ Hyponatremia; ⑦ Lupus erythematosus, which may aggravate the condition or induce flare-ups; ⑧ Pancreatitis; ⑨ Sympathectomy (enhanced antihypertensive effect); ⑩ Infants with jaundice. 4. Follow-up tests: ① Serum electrolytes; ② Blood glucose; ③ Serum uric acid; ④ Serum creatinine and urea nitrogen; ⑤ Blood pressure. 5. Start with the minimum effective dose to minimize side effects and reduce reflex renin and aldosterone secretion. 6. Patients prone to hypokalemia should receive potassium supplements or use the drug in combination with a potassium-sparing diuretic, as appropriate.
[Special Use]
Precautions for Children:
Use with caution in infants with jaundice
Precautions for Pregnancy and Lactation:
1. Can cross the placenta. Has no preventive effect on hypertension syndrome. Therefore, use with caution in pregnant women.
2. Not suitable for lactating women.
Precautions for Elderly:
Contraindicated for elderly patients.
[Drug Interactions]
1. Adrenocortical hormones, adrenocorticotropic hormone, estrogen, and amphotericin B (intravenous) can reduce the diuretic effect of this drug and increase the risk of electrolyte imbalances, especially hypokalemia.
2. Nonsteroidal anti-inflammatory analgesics, especially indomethacin, can reduce the diuretic effect of this drug, related to its inhibition of prostaglandin synthesis.
3. Concomitant use with sympathomimetic amines may weaken the diuretic effect.
4. Cholestyramine (cholestyramine) can reduce gastrointestinal absorption of this drug. Therefore, this drug should be taken 1 hour before or 4 hours after oral administration of cholestyramine.
5. Concomitant use with dopamine may enhance the diuretic effect.
6. When used in combination with antihypertensive drugs, the diuretic and antihypertensive effects are enhanced.
7. When used in combination with antigout drugs, the dosage of the antigout drugs should be adjusted.
8. It weakens the effects of anticoagulants, primarily due to a decrease in plasma volume after diuresis, an increase in coagulation factor levels, and improved blood supply to the liver, which increases coagulation factor synthesis.
9. It reduces the effects of hypoglycemic drugs.
10. When digitalis, amiodarone, and other drugs are used in combination with this drug, caution should be exercised to prevent side effects caused by hypokalemia.
11. When used in combination with lithium preparations, this drug can reduce renal clearance of lithium, increasing lithium nephrotoxicity.
12. When used in combination with this drug, methenamine is inhibited from converting to formaldehyde, resulting in reduced efficacy.
13. It enhances the effects of non-depolarizing muscle relaxants, which is associated with a decrease in serum potassium.
14. When used in combination with sodium bicarbonate, the risk of hypochloremic alkalosis increases.
[Pharmacological Actions]
1. Effects on water and electrolyte excretion. ① Diuretic effect: Increased urinary excretion of sodium, potassium, chloride, phosphorus, and magnesium, while decreased urinary calcium excretion. The mechanism of action of this class of drugs is primarily through inhibition of sodium chloride reabsorption in the distal tubule proximal and, to a lesser extent, proximal tubules, thereby increasing Na+-K+ exchange in the distal tubules and collecting ducts and increasing K+ secretion. This mechanism of action is not fully understood. All drugs in this class inhibit carbonic anhydrase activity to varying degrees, which may explain their effects on the proximal tubules. These drugs also inhibit phosphodiesterase activity, reducing tubular fatty acid uptake and mitochondrial oxygen consumption, thereby inhibiting active tubular reabsorption of Na+ and Cl-. ② Antihypertensive effect: In addition to diuretic and natriuretic effects, extrarenal mechanisms may also contribute to blood pressure reduction, possibly by increasing gastrointestinal Na+ excretion. 2. Effects on renal hemodynamics and glomerular filtration function. Due to decreased renal tubular reabsorption of water and sodium, increased intratubular pressure and increased water and sodium flow through the distal convoluted tubule stimulate the macula densa through the tubuloglomerular reflex, increasing renal secretion of renin and angiotensin. This leads to renal vasoconstriction, decreased renal blood flow, constriction of the afferent and efferent glomerular arterioles, and a decrease in glomerular filtration rate. This decrease in renal blood flow and glomerular filtration rate, as well as its lack of effect on the loop of Henle, are the main reasons why this class of drugs has a far inferior diuretic effect compared to loop diuretics.
[Storage] Store in a dark, sealed container.
[Strength] 25 mg
[Packaging] Plastic bottle, 100 tablets per bottle.
[Expiry Date] 36 months.
[Approval Number] National Medicine Standard H32021683
[Manufacturer] Company Name: Changzhou Pharmaceutical Factory Co., Ltd.
