Hypertension, or high blood pressure, results from blood being pumped through narrowed arteries. If this condition is not controlled, hypertension puts you at risk for strokes and heart attacks. The Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure classifies hypertension as being over 140/90 mmHg, or millimeters of mercury. Hydrochlorothiazide, a drug in the class of thiazide diuretics, is most often recommended as the first choice of treatment for hypertension.
Function
Hydrochlorothiazide acts on a part of the kidney called distal convoluted tubule and blocks the reabsorption of salt, chloride and water. This leads to a decrease in the circulating blood volume, thereby reducing your blood pressure.
Side Effects
Dehydration is a side effect of this drug because it causes diuresis, or increased urination. It may also cause hypokalemia, which is a decreased amount of potassium in your body. Potassium is an important electrolyte. If it drops too low, you may feel general weakness, nausea and vomiting. Another side effect is hyperglycemia, where blood glucose levels increase.
Warning
Thiazide diuretics, including hydrochlorothiazide, should be avoided if you are pregnant or breast-feeding because there are no controlled studies indicating its safety. If you know that your kidneys don't work well and you have impaired renal function, this drug may not be effective for you.
Medication Interactions
If you take digoxin, lithium and non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen, the use of hydrochlorothiazide may interact with these medications. It is important to speak with your doctor regarding your other medications if you are prescribed a thiazide diuretic. Also, if you are using other drugs to help lower your blood pressure in addition to this one, the combination may cause your blood pressure to decrease below a healthy range.
Considerations
It is important to follow your doctor's instructions on how to take hydrochlorothiazide. Generally, these might include taking your medication first thing in the morning so your sleep is not disturbed by the need to urinate during the night and maintaining your fluid intake due to the risk of dehydration. Your doctor may also encourage you to eat foods rich in potassium, such as spinach and tomatoes.
References
- National Heart, Lung and Blood Institute: Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure
- Mayo Clinic: High Blood Pressure (Hypertension)
- "Pharmacology for Nursing"; Jeanne Wissmann Ph.D, R.N., CNE; 2008
