Diuretics, also known as water pills are prescribed by doctors to treat various health conditions like high blood pressure, kidney and liver problems, glaucoma, edema, etc. They help body get rid of excess salt and water.
Mode of Action
So how do they work?
Presence of too much salt can cause accumulation of water inside the blood vessels which raises blood pressure. Diuretics control the excretory action of the kidneys and help removing the excess salt and water from the body. Thus the amount of fluid inside the blood vessels decreases, which further reduces the pressure on the arterial walls. Simply put, blood pressure is lowered.
The drugs also help relaxing blood vessels in order to normalize blood circulation.
Why are diuretics prescribed?
As explained before, diuretics are used to get rid of excess salt and fluid from the body. This forms the basis for treating a wide range of health disorders, which include:
- Congestive heart failure
- High blood pressure
- Swelling of tissues or edema
- Kidney disorders
- Female hirsutism – male hair growth in females
- Frequent urination in case of diabetes insipidus
Types of Diuretics
There are 3 main categories of diuretics, which can be used singly or as a combination pill. They are:
- Thiazides- used to treat hypertension or high blood pressure and edema. E.g.- bendroflumethiazide, hydrochlorothiazide, metolazone, indapamide
- Loop diuretics- used mainly in emergency cases of symptomatic heart failure and for reducing fluid retention in chronic kidney disease. E.g.- furosemide, bumetanide, torasemide, Ethacrynic acid
- Potassium-sparing diuretics– help to retain potassium and get rid of excess fluids. They do not lower blood pressure and is often used along with another diuretic. E.g.- amiloride, triamterene, eplerenone, triamterene, spironolactone
Other 2 categories which are also used for treatment include:
- Osmotic diuretics- used for treatment of cerebral edema. E.g.- mannitol
- Carbonic anhydrase inhibitors- used for treatment of glaucoma and mountain sickness. E.g.- acetazolamide
Side Effects of Diuretics
Usually there are no side effects of diuretics as doctors prescribe a certain dosage for treating the medical condition. Side effects show up when the dose is increased and the body takes some time to adjust to the medicine. Possible side effects are:
- Increased urination (mostly by loop diuretics)
- Dizziness, weakness and lethargy
- Increased thirst or dehydration
- Blurred vision, headache, confusion
- Increased sweating
- Cramping in muscles
- Decreased sodium in blood
- Rashes on skin
- Loss of appetite, vomiting
- Rise in blood sugar and cholesterol
- Risk of high uric acid in body (gout)
- Risk of developing diabetes (thiazide diuretic)
In rare cases, diuretics can also affect sexual health of men characterized by erectile problems, impotence and male breast enlargement. Women can experience menstrual irregularities.
Points to remember while taking diuretics
Your doctor will definitely explain you the precautions needed while taking diuretics. However, for your help we define them here:
- Do not take any medicine (even OTC) in combination with diuretics without consulting your doctor
- Let your doctor know if you are already taking any medicines
- Your doctor is most likely to advice intake of diuretics in the morning. So don’t miss the dose
- You need to fix regular appointments with your doctor to monitor blood glucose and electrolyte balance in the body
- Consult your doctor right away if the side effects persist for few days
- You should be mentally prepared to take the medicines on long term basis
Make sure you follow the dose of the diuretics as suggested by your doctor to notice improvement in your health. Feel free to consult your doctor on having any doubts in your mind.
Date last updated: January 17, 2015