Thiazide and Thiazide-like Diuretics in the Treatment of High Blood Pressure
This class of diurectics (water pills) is the most commonly prescribed class of blood pressure lowering drugs (antihypertensives). There are a number of them, and most of them have several versions made by different manufacturers (list of available thiazide diuretics). Thazide diuretics are used both alone, and in combination with other drugs, for the treatment of high blood pressure.
Thiazides are also known as benzothiadizines. In addition to increasing urine flow, thiazide diuretics increase the loss of sodium (Na+) and chloride (Cl-) from the body via urine.
See the discussion of diuretics for an explanation how they can lower blood pressure.
Use of thiazide and thiazide-like diuretics
Diuretics are;
- As effective as other treatments of high blood pressure
- Well tolerated (i.e. very few people stop taking them due to side effects)
- Taken once daily and do not need to be titrated in dose (i.e. do not need to slowly increase dose)
- Generally inexpensive
- Often used for initial therapy
- Takes 2 to 4 weeks for full effect
- Effects are additive with other blood pressure treatments (i.e. get further decreases in blood pressure)
In addition, to treatment of high blood pressure, thiazide diuretics are used for treatment of edema (fluid retention), which is associated with a number of problems, including heart failure. In fact the development of heart failure can be a consequence untreated high blood pressure. Thiazide diuretics can reduce the loss of calcium from the body in urine and so may be useful for those with osteoporosis.
Potential side effects of thiazide and thiazide-like diuretics
As stated above thiazide diuretics are well tolerated by most people. Most potential side effects are due to the loss of water, sodium, chloride and other ions such as potassium and magnesium in the urine, and an increase of calcium and uric acid in the body. Increased levels of uric acid can lead to gout or kidney stones.
Thaizide diuretics can decrease glucose tolerance. This can lead to increased glucose levels (hyperglycemia). Therefore, those with diabetes should be carefully monitored and the dosage of insulin and drugs for diabetes adjusted if necessary. Treatment with thiazide diuretics can also unmask latent (hidden) diabetes.
There may be side effects when this drug is taken in combination with certain other drugs. Make sure that your health care provider is aware of any, and all, prescription drugs, non-prescription drugs, herbal supplements, nutritional supplements and vitamins that are being taken.