Chlorthalidone 50mg Tablets

Chlorthalidone is a phthalimidine derivative, a long-acting sulfonamide diuretic, chemically related to thiazide diuretics. It acts primarily in the cortical diluting segment of the distal convoluted tubule, where it inhibits the reabsorption of sodium and chloride ions by blocking the Na+/Cl- cotransporter (NCC). This leads to increased excretion of sodium, chloride, and water, as well as potassium and magnesium. It also decreases calcium excretion. The antihypertensive effect is initially due to a reduction in plasma volume and cardiac output, followed by a decrease in peripheral vascular resistance with chronic use.

Serious Side Effects: Seek Medical Attention Immediately

Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you experience any of the following symptoms, contact your doctor or seek medical help right away:

Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Signs of fluid and electrolyte problems, such as:
+ Mood changes
+ Confusion
+ Muscle pain or weakness
+ Fast or abnormal heartbeat
+ Severe dizziness or passing out
+ Increased thirst
+ Seizures
+ Feeling very tired or weak
+ Decreased appetite
+ Unable to pass urine or change in the amount of urine produced
+ Dry mouth
+ Dry eyes
+ Severe upset stomach or vomiting
Signs of kidney problems, such as:
+ Unable to pass urine
+ Change in how much urine is passed
+ Blood in the urine
+ Sudden weight gain
Signs of pancreatitis (pancreas problem), such as:
+ Severe stomach pain
+ Severe back pain
+ Severe upset stomach or vomiting
Abnormal sensations, such as:
+ Burning
+ Numbness
+ Tingling
Erectile dysfunction
Restlessness
Yellowing of the skin or eyes
Changes in vision
Fever, chills, or sore throat
Unexplained bruising or bleeding
Feeling very tired or weak

Other Possible Side Effects

Like all medications, this drug can cause side effects. However, many people experience no side effects or only mild ones. If you experience any of the following side effects or any other symptoms that bother you or do not go away, contact your doctor:

Dizziness
Fatigue
Weakness
Headache
Constipation
Diarrhea
Upset stomach
Vomiting
Decreased appetite
Stomach cramps

Reporting Side Effects

This is not an exhaustive list of possible side effects. If you have questions or concerns about side effects, contact your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.

Before Taking This Medication: Important Information to Share with Your Doctor

It is essential to inform your doctor about the following:

Any allergies you have, including allergies to this medication, its components, or other substances. Be sure to describe the allergic reaction and its symptoms.
A known sulfa allergy.
If you have difficulty urinating.
If you are breastfeeding. Note that you should not breastfeed while taking this medication.

This list is not exhaustive, and it is crucial to discuss all your medications (including prescription, over-the-counter, natural products, and vitamins) and health conditions with your doctor and pharmacist. They will help determine if it is safe to take this medication with your other medications and health issues. Never start, stop, or adjust the dosage of any medication without first consulting your doctor.

It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication. This will help ensure your safety and prevent potential interactions with other treatments.

To minimize the risk of accidents, avoid driving and engaging in activities that require alertness until you understand how this medication affects you. When standing up from a sitting or lying down position, rise slowly to reduce the likelihood of dizziness or fainting. Be cautious when climbing stairs to avoid falls.

Regularly check your blood pressure as instructed by your healthcare provider. This medication may cause elevated cholesterol and triglyceride levels, so it is crucial to discuss this with your doctor.

Follow your doctor's instructions for blood tests, as this medication may impact certain lab results. Inform all your healthcare providers and laboratory personnel that you are taking this medication to ensure accurate test interpretations.

Before consuming alcohol, marijuana, or other substances that may impair your actions, consult with your doctor. If you have diabetes, closely monitor your blood sugar levels, as this medication can affect them. Be aware of signs of high blood sugar, such as confusion, drowsiness, increased thirst or hunger, frequent urination, flushing, rapid breathing, or fruity-smelling breath, and report them to your doctor.

If you have high blood pressure, consult with your doctor before taking over-the-counter (OTC) products that may increase blood pressure, including cough and cold medications, diet pills, stimulants, non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or naproxen, and certain natural products or aids.

This medication is a potent diuretic, which can lead to excessive loss of water and electrolytes (such as potassium) in the blood. Your doctor will closely monitor you to adjust the dosage according to your body's needs. Be aware of the risk of gout attacks and discuss any concerns with your doctor.

If you are on a low-sodium or sodium-free diet, inform your doctor, as this may affect your treatment plan. This medication can increase your sensitivity to the sun, making you more prone to sunburn. Take precautions when exposed to sunlight, and report any unusual sunburn or sensitivity to your doctor.

If you are pregnant or planning to become pregnant, discuss the benefits and risks of taking this medication with your doctor to ensure your safety and the well-being of your unborn child.

• Anuria
• Hypersensitivity to chlorthalidone or sulfonamide-derived drugs

• Lithium (increased lithium toxicity due to decreased renal clearance)
• Dofetilide (increased risk of QT prolongation and torsades de pointes)
• Cisapride (increased risk of QT prolongation)
• Nonsteroidal Anti-inflammatory Drugs (NSAIDs) (may reduce diuretic, natriuretic, and antihypertensive effects of chlorthalidone; increased risk of renal impairment)
• Corticosteroids (increased risk of hypokalemia)
• Digoxin (increased risk of digoxin toxicity due to hypokalemia)
• Other antihypertensives (additive hypotensive effects)
• Neuromuscular blocking agents (prolonged neuromuscular blockade due to hypokalemia)

• Antidiabetic agents (may decrease glucose tolerance, requiring adjustment of antidiabetic therapy)
• Cholestyramine/Colestipol (may reduce absorption of chlorthalidone; administer chlorthalidone 1 hour before or 4 hours after)
• Alcohol, barbiturates, or narcotics (may potentiate orthostatic hypotension)
• Pressor amines (e.g., norepinephrine) (decreased arterial responsiveness)
• Allopurinol (increased risk of hypersensitivity reactions to allopurinol)
• Amantadine (increased risk of amantadine toxicity)
• Cyclosporine (increased risk of hyperuricemia and gout)

• Calcium salts (increased risk of hypercalcemia)
• Vitamin D (increased risk of hypercalcemia)

• Signs of electrolyte imbalance (e.g., muscle weakness, cramps, fatigue, irregular heart beat, confusion, nausea, vomiting, excessive thirst)
• Signs of dehydration (e.g., dry mouth, decreased urination, dizziness, lightheadedness)
• Symptoms of gout (e.g., acute joint pain, swelling, redness)
• Symptoms of hyperglycemia (e.g., increased thirst, increased urination, fatigue)
• Orthostatic hypotension (dizziness upon standing)

Pregnancy Category C. Chlorthalidone should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Routine use of diuretics in otherwise healthy pregnant women with edema is not recommended as it may lead to decreased placental perfusion.

Chlorthalidone is excreted in breast milk. Due to the potential for serious adverse reactions in the nursing infant (e.g., electrolyte disturbances, suppression of lactation), a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.

Use with caution. Dosing is weight-based. Safety and efficacy in infants and very young children are not well-established. Electrolyte imbalances are a significant concern.

Elderly patients may be more sensitive to the effects of chlorthalidone, particularly regarding electrolyte imbalances (e.g., hypokalemia, hyponatremia) and orthostatic hypotension. Lower starting doses and careful monitoring are recommended.

• Chlorthalidone has a significantly longer half-life (40-60 hours) compared to hydrochlorothiazide (6-15 hours), allowing for sustained blood pressure control with once-daily dosing.
• Current hypertension guidelines (e.g., JNC 8, ACC/AHA) often recommend chlorthalidone as a preferred thiazide-type diuretic due to its superior efficacy in reducing cardiovascular events compared to hydrochlorothiazide in some studies.
• Administer in the morning to prevent nocturia (nighttime urination).
• Monitor for electrolyte imbalances (especially potassium, sodium, magnesium) and uric acid levels, particularly during initiation of therapy and dose adjustments.
• May cause photosensitivity; advise patients to use sunscreen and protective clothing.
• Less effective in patients with severe renal impairment (CrCl <30 mL/min); loop diuretics are generally preferred in these cases.

• ACE inhibitors (e.g., lisinopril)
• Angiotensin Receptor Blockers (ARBs) (e.g., losartan)
• Calcium Channel Blockers (CCBs) (e.g., amlodipine)
• Beta-blockers (e.g., metoprolol)
• Loop Diuretics (e.g., furosemide, torsemide - for more potent diuresis, especially in renal impairment or heart failure)
• Potassium-sparing Diuretics (e.g., spironolactone, amiloride - often used in combination to counteract potassium loss)

If your symptoms or health issues persist or worsen, it's essential to contact your doctor for further guidance. To ensure your safety, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so be sure to check with your pharmacist for more details. If you have any questions or concerns about your medication, don't hesitate to reach out to your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek medical attention. When seeking help, be prepared to provide information about the medication taken, the amount, and the time it happened.