What are Thiazide Diuretics?

Diuretics, sometimes referred to as water tablets, are drugs that act on different areas of the kidneys in order to promote urination. These drugs are usually prescribed to treat high blood pressure. Thiazide diuretics, specifically act on the distal convoluted tubules (DCT) of the kidneys. The DCT are parts of the kidneys where salt is reabsorbed. By acting on the DCT, this type of drug generally helps reduce the amount of salt and water in the body.

Aside from eliminating salt and water through urination, thiazide diuretics also cause blood vessels to widen. These combined actions of the drug inside the body frequently result in the reduction of high blood pressure. Thiazide diuretics are also used in the treatment of edema. Edema is a condition where swelling in the arms and legs occurs due to the accumulation of fluids in the tissue caused by heart failure and other diseases.

Side-effects of thiazide diuretics include decreased blood levels of potassium, known as hypokalemia, and magnesium, known as hypomagnesemia, as well as increased levels of calcium in the blood, also known as hypercalcemia. Imbalance of these substances in the body may result in confusion, irregular heart beats, and weakness. Patients may also have increased amounts of sugar, fat, and uric acid in their blood. Other side effects include rashes, itchiness, vomiting, headache, and dizziness. Close monitoring of patients is often necessary during treatment with thiazide diuretics in order to monitor their reactions.

Thiazide diuretics are generally not recommended for patients with kidney failure because kidney disorders greatly decrease the effectiveness of the drug. Patients with diabetes or gouty arthritis should inform their doctors about their conditions during check up because use of this drug can aggravate their symptoms. Gouty arthritis is characterized by increased uric acid in the patient's blood often leading to joint pain. Elderly men with enlarged prostate, and breastfeeding mothers must also take thiazide diuretics with caution. The drug is also not recommended for pregnant women.

These drugs are usually taken orally. They could be in tablet, capsule or liquid form. The recommended time for intake is frequently early in the morning in order to avoid sleep disturbances at night. Patients are also advised to eat foods rich in potassium, such as fruits and vegetables since these drugs may lower potassium levels inside the body.