Diuretic Medications For Blood Pressure

Diuretics, known as water pills, are among the most frequently prescribed medications. These drugs are prescribed by doctors to treat a variety of ailments, including congestive heart failure and high blood pressure.

What are Diuretics?

Diuretics, often referred to as “water pills” or “fluid pills,” are a drug class of medications that help your kidneys excrete more sodium in your urine. They work by reducing sodium reabsorption at several locations in your kidneys which increases sodium and water losses through urination. Correspondingly, the most common side effect of taking water pills is frequent urination.

The amount of fluid passing through your veins and arteries is reduced as a result of sodium's ability to eliminate water from your blood, causing your blood pressure to decrease as well as relieving symptoms such as ankle swelling.

There are various types of diuretic drug classes, including loop diuretics, potassium-sparing diuretics, and thiazide diuretics. Each drug class operates differently and affects different kidney cell regions called nephrons.

What Are Diuretics Used For?

Diuretics are prescribed to treat medical conditions such as heart failure, kidney failure, and liver cirrhosis (late stage of scarring (fibrosis) of the liver) that manifest as fluid retention (also known as edema). They are also effective at lowering blood pressure, such as thiazides and loop diuretics, and some diuretics are used as a first-line treatment for high blood pressure (hypertension).

Your doctor may add additional blood pressure medications to your treatment regimen if diuretics are unable to sufficiently decrease your blood pressure.

• High blood pressure —Diuretics lower blood pressure, which reduces your chance of a heart attack or stroke.
• Heart failure —Loop diuretics are commonly used to ease swelling and congestion in your lungs.
• Tissue swelling (edema) —Diuretics reduce edema, which typically affects your legs.
• Liver failure —Diuretics ease the fluid buildup in individuals with cirrhosis.
• Certain kidney disorders (i.e.kidney stones)
• Glaucoma —Diuretics have been shown to reduce the pressure in your eye(s).

What Are The Different Types of Diuretics?

As mentioned, there are 3 types of diuretics: thiazide, potassium sparing and loop diuretics.

Thiazide Diuretics

Thiazide diuretics inhibit sodium absorption in the distal convoluted tubules, causing increased excretion of sodium, chloride, water, and potassium into urine. These medications are primarily used in hypertension treatment. Thiazide diuretics are inexpensive, effective, and have mild side effects in most individuals.

Thiazide diuretics should be taken in the morning to avoid nocturia (urinating frequently at night).

Common side effects:

• Hypokalemia (potassium deficiency in your blood; serum potassium level of less than 3.5 mEq/L)
• Hypomagnesemia (magnesium deficiency in your blood; serum magnesium level of less than 1.4 mEq/L)
• Hyponatremia (lower than normal sodium level in your blood; serum sodium level of less than 135 mEq/L)
• Hypercalcemia (above normal calcium level in your blood serum level over 12 mg/dL)
• Hyperuricemia (above normal uric acid in your blood; serum level over 7 mg/dL)
• Elevated lipids, such as increased LDL and TG (triglycerides)
• Hyperglycemia (above normal glucose; greater than 125 mg/dL while fasting)
• Dizziness
• Photosensitivity
• Rash

Drug interactions with thiazide diuretics:

Avoid drugs that can cause sodium and water retention, such as Nonsteroidal anti-inflammatory drugs (NSAIDs), as they can decrease the effectiveness of antihypertensive medications.

All antihypertensive drugs (medications used to treat high blood pressure) can enhance the blood pressure lowering effects of other drugs; carefully monitor your blood pressure when adding on treatment.

2. Potassium-Sparing Diuretics

Potassium-sparing diuretics, also called aldosterone receptor antagonists (ARA), are medications that increase diuresis (urination) without the loss of potassium.

This drug class functions as antagonists at the aldosterone receptor or as weak diuretics by interfering with the sodium-potassium exchange in the distal convoluted tubule of your kidneys

When potassium-sparing diuretics are used to counteract the impact of aldosterone, more sodium and water can pass into the collecting ducts of your kidneys, increasing diuresis.

These medications do not produce hypokalemia (low potassium levels) because they do not cause the secretion of potassium during diuresis. When combined with medications that also retain potassium, such as ACE inhibitors, they can cause hyperkalemia (high potassium levels).

Common side effects of potassium-sparing diuretics:

• Dehydration
• Hyponatremia (low sodium levels in your blood)
• Dizziness

Black Box Warning (the highest safety-related warning that medications can have assigned by the FDA): Amiloride and triamterene may cause hyperkalemia (potassium serum level greater than 5.5 mEq/L). This is more likely in individuals with diabetes, renal impairment, or elderly people.

3. Loop Diuretics

Loop diuretics are often used to decrease fluid volume to make it easier for your heart to pump. This drug class blocks sodium and chloride reabsorption in the ascending limb of the loop of Henle, interfering with the chloride-binding co-transport system. They increase the excretion of sodium, potassium, chloride, magnesium, calcium, and water. Loop diuretics are also used to reduce congestive symptoms (reduce preload) and restore euvolemia (or “dry” weight).

If the response to loop diuretics is poor, a combination with thiazide-type diuretics, such as metolazone, can be useful.

These medications can be used for blood pressure reduction in individuals with renal impairment when other options are not adequate.

Loop diuretics should be taken in the morning to avoid nocturia (urinating frequently at night).

Common side effects of loop diuretics:

• Hypokalemia (lower than normal potassium in your blood; serum potassium level lower than 3.5 mEq/L)
• Hypomagnesemia (lower than normal magnesium in your blood; serum magnesium level lower than 1.8 mg/dL)
• Hypocalcemia (lower than normal calcium in your blood; corrected serum calcium level lower than 2.12 mmol/L)
• Hypochloremia (lower than normal chloride in your blood; serum chloride level lower than 95 mEq/L)
• Metabolic alkalosis (a condition that occurs when your blood becomes overly alkaline; pH over 7.45)
• Hyperuricemia (abnormally high level of uric acid in the blood, affiliated with gout)
• Hyperglycemia (increased glucose in your bloodstream)
• Increased triglycerides
• Increased total cholesterol
• Orthostatic hypotension (a condition in which your blood pressure quickly drops when you stand up from a sitting or lying position)
• Photosensitivity (extreme sensitivity to ultraviolet (UV) rays from the sun and other light sources)
• Ototoxicity (ear damage), including hearing loss, tinnitus, and vertigo

Drug interaction with loop diuretics:

NSAIDs (Non-Steroidal Anti-Inflammatory Drugs)—should be avoided in individuals with heart failure. NSAIDs can increase sodium and water retention, which decreases the effect of the loop diuretics and can lead to renal impairment.

Speak With Your Doctor

Ask your healthcare provider which diuretic is the best fit for you and send your prescription to Marley Drug. Save up to 95% compared to your local pharmacy by using Marley Drug.