Hydrochlorthiazide

Hydrochlorothiazide (Hydrochlorothiazide) is a medication in the thiazide diuretic group that is used to treat high blood pressure (hypertension) and swelling caused by heart failure, kidney disease, or other conditions.

Hydrochlorthiazide works by increasing the excretion of sodium and water through the urine, resulting in a decrease in blood volume and consequently lower blood pressure. It can also be used in combination with other medicines to achieve better blood pressure control.

It is important to use hydrochlorthiazide only as prescribed by your doctor, as this medication may have side effects and may interact with other medications.

Indications Hydrochlorthiazide

Hydrochlorthiazide may be prescribed in the following cases:

1. Hypertension (high blood pressure): Hydrochlorthiazide is used to lower blood pressure in patients with hypertension.
2. Swelling: The medicine may be used to treat swelling that may be caused by heart failure, kidney disease, hepatitis, or other conditions.
3. Nephrolithiasis (urolithiasis): Hydrochlorthiazide may sometimes be used to prevent or relieve kidney stones.

Release form

Hydrochlorthiazide is available in several dosage forms:

1. Tablets: Hydrochlorthiazide is usually supplied as oral tablets. The tablets can have different dosages, such as 12.5 mg, 25 mg, or 50 mg.
2. Capsules: In some cases, hydrochlorthiazide may be available in capsule form, which are also intended for oral administration.
3. Solution: Hydrochlorthiazide may also be available as an oral liquid solution. This option may be useful for those who have difficulty swallowing solid forms of medication.
4. Injectable Solution: In some cases, especially in situations requiring rapid control of high blood pressure, hydrochlorthiazide may be available as an injectable solution for intravenous or intramuscular administration.

Pharmacodynamics

1. Diuresis: Hydrochlorthiazide acts as a diuretic, stimulating the excretion of sodium and water from the body by reducing sodium reabsorption in the kidneys. This occurs by blocking sodium reabsorption in the initial segment of the renal distal tubule.
2. Decrease inplasma volume: A decrease in sodium reabsorption leads to a decrease in circulating plasma fluid volume, which in turn decreases circulating blood volume and blood pressure.
3. Reduction in blood volume: In addition to its diuretic action, hydrochlorthiazide may also cause vasodilation by reducing blood volume, which may further reduce blood pressure.
4. Decreased calcium reabsorption: Hydrochlorthiazide may also lead to decreased calcium reabsorption in the kidneys, which may be useful in the treatment of some forms of kidney stones and osteoporosis.

Pharmacokinetics

Here are some basic aspects of the pharmacokinetics of hydrochlorthiazide:

1. Absorption: Hydrochlorthiazide is usually rapidly and completely absorbed from the gastrointestinal tract after oral administration.
2. Metabolism: Hydrochlorthiazide undergoes minimal metabolic transformation. Most of the active substance is retained in unchanged form.
3. Distribution: It is distributed in the body, predominantly in the extracellular space, tissues and fluids.
4. Excretion: Hydrochlorthiazide is excreted mainly through the kidneys. Most of its metabolites are also excreted by the kidneys.
5. Half-life: The half-life of hydrochlorthiazide is about 6-15 hours, depending on individual patient characteristics.
6. Pharmacokinetics in renal dysfunction: In renal dysfunction, especially in significant renal insufficiency, clearance of hydrochlorthiazide decreases, which may lead to its accumulation in the body and enhancement of therapeutic effect. Therefore, when using hydrochlorthiazide, it is necessary to take into account the degree of renal function in the patient.
7. Effect of food: Taking hydrochlorthiazide with food may reduce the rate of absorption and delay the onset of action.

Dosing and administration

Hydrochlorthiazide is usually taken orally in the form of tablets or capsules. The dosage and regimen may vary depending on the patient's condition and the doctor's recommendations. Here are general guidelines for the use and dosage of hydrochlorthiazide:

1. Hypertension (high blood pressure):

   • The usual starting dose for adults is 12.5-25 mg per day, taken once or divided into two doses.
   • If necessary, the dose may be increased to 50 mg per day, but usually the maximum recommended daily dose is 50 mg.

2. Edema associated with heart failure:

   • The dosage may be higher and depends on the degree of edema and response to therapy.
   • The usual starting dose is 25-100 mg per day, taken once or divided into several doses.

3. Other states:

   • For other conditions, such as preventing kidney stones, the dosage and regimen may vary and should be determined by a physician.

The important thing to remember is the following:

• Hydrochlorthiazide should be taken at the same time each day to ensure a stable therapeutic effect.
• It should be taken with or immediately after meals to reduce possible gastrointestinal side effects.
• Blood pressure and kidney function should be monitored regularly while using hydrochlorthiazide.

Use Hydrochlorthiazide during pregnancy

The use of hydrochlorthiazide during pregnancy may be undesirable and requires special attention and assessment of risks and benefits to the mother and fetus.

First, hydrochlorthiazide may cross the placenta and affect the developing fetus. Some studies have shown an association between taking thiazide diuretics such as hydrochlorthiazide during pregnancy and possible unwanted effects in the fetus, such as low water supply, hypokalemia (low blood potassium levels) and possibly the risk of fetal failure.

Second, the use of hydrochlorthiazide may increase the risk of pyelonephritis (inflammation of the renal pelvis and kidney) in pregnant women.

Contraindications

1. Allergy: People with a known allergy to hydrochlorthiazide or other thiazide diuretics should avoid its use.
2. Hyperkalemia: Hydrochlorthiazide may cause an increase in blood potassium levels. Therefore, it should be used with caution in patients with impaired renal function or taking other medicines that may also affect potassium levels.
3. Hyponatremia: The use of hydrochlorthiazide may cause a decrease in blood sodium levels. This may be especially dangerous in the elderly and patients with kidney or heart disease.
4. Renal insufficiency: In patients with severe renal dysfunction or renal impairment the use of hydrochlorthiazide may be undesirable.
5. Hypercalcemia: Hydrochlorthiazide may cause an increase in blood calcium levels. Therefore, it should be used with caution in patients with hypercalcemia.
6. Diabetes mellitus: Hydrochlorthiazide can raise blood sugar levels, which can be a problem for patients with diabetes.
7. Leukopenia: The use of hydrochlorthiazide may cause a decrease in the level of white blood cells in the blood, which may increase the risk of infections.

Side effects Hydrochlorthiazide

1. Dehydration and electrolyte imbalance: Excessive loss of fluids and electrolytes such as sodium, potassium, and chlorine can lead to dehydration as well as hypokalemia (low blood potassium), which can cause symptoms such as fatigue, weakness, irregular pulse, and muscle cramps.
2. Hypotension: A drop in blood pressure can cause dizziness, a feeling of weakness, drowsiness, or even fainting.
3. Hyperglycemia: Hydrochlorthiazide may increase blood glucose levels in some people, which is especially important in patients with diabetes.
4. Hyperuricemia: This is an increase in uric acid levels in the blood, which can increase the risk of gout and kidney stones.
5. Photosensitivity: Hydrochlorthiazide may make the skin more sensitive to ultraviolet light, which can lead to sunburn or other skin problems with prolonged exposure to sunlight.
6. Hypercalcemia: Rarely, but hydrochlorthiazide can cause an increase in blood calcium levels, which can lead to various symptoms and complications.
7. Renal dysfunction: In some people hydrochlorthiazide may cause worsening of renal function or even the appearance of acute renal failure.
8. Dyspepsia: Gastric disorders such as nausea, vomiting, or diarrhea may occur.

Overdose

An overdose of hydrochlorthiazide can lead to serious consequences and requires immediate medical attention. Symptoms of overdose may include the following:

1. Severe dehydration: The patient may experience severe thirst, dry mouth, decreased urinary frequency, hypernatremia (high blood sodium levels), and hypovolemia (decreased blood volume).
2. Electrolyte imbalance: Overdose can lead to hypokalemia (low blood potassium levels), which can cause weakness, muscle cramps, and irregular heart rhythm.
3. Cardiac problems: Possible cardiac arrhythmias including tachycardia (rapid heart rate), arterial hypotension (decreased blood pressure).
4. Renal Failure: Expressed as acute renal failure due to dehydration and decreased blood flow in the kidneys.
5. Seizures: In case of severe overdose, seizures and convulsive syndrome may occur.

Interactions with other drugs

Hydrochlorthiazide may interact with different medicines, which may alter their effectiveness, increase side effects, or cause new reactions. Below are some of the main medicines and classes of medicines with which hydrochlorthiazide may interact:

1. Potassium-boosting drugs: Use of hydrochlorthiazide in combination with drugs that increase blood potassium levels (e.g., potassium supplements, spironolactone, amiloride) may result in hyperkalemia.
2. Potassium-lowering drugs: Use of hydrochlorthiazide in combination with drugs that lower blood potassium levels (e.g., asthma medications such as beta-2 agonists) may increase the risk of hypokalemia.
3. Diabetes medications: Hydrochlorthiazide may increase blood sugar levels, so taking it in combination with diabetes medications (e.g. Insulin or sulfonylureas) may require dosage adjustment of the latter.
4. Blood pressure-lowering drugs: Combining hydrochlorthiazide with other antihypertensive drugs (e.g., beta-blockers, angiotensin-converting enzyme inhibitors, calcium antagonists) may increase the hypotensive effect.
5. Drugs affecting the heart rhythm: Hydrochlorthiazide may increase the cardiotoxic effects of certain drugs such as cyfidipine or amidarone.
6. NSAIDs: Use of non-prescribed anti-inflammatory drugs (e.g., ibuprofen, acetaminophen) in combination with hydrochlorthiazide may decrease its effectiveness and increase the risk of renal dysfunction.
7. Lithium: Hydrochlorthiazide may increase lithium levels in the blood, which can lead to lithium toxicity.

Storage conditions

Storage conditions for hydrochlorthiazide generally follow generally accepted standards for most medications. The following are generally recommended:

1. Temperature: Store hydrochlorthiazide at room temperature, usually 20 to 25 degrees Celsius.
2. Light: Avoid exposure of the hydrochlorthiazide package or container to direct sunlight. The medicine should be stored in a dark place.
3. Humidity: Avoid high humidity. The medicinal product should be stored in a dry place.
4. Packaging: Keep hydrochlorthiazide in its original package or container that is well closed.
5. Children and pets: Keep the medicine out of the reach of children and pets to prevent accidental use.
6. Avoid extreme conditions: Do not store hydrochlorthiazide in places with excessively high or low temperatures, such as the freezer or bathroom.
7. Expiration date: Follow the information on the package or in the instructions for use regarding the expiration date. Do not use hydrochlorthiazide after the expiry date.