Triamterene 37.5mg/ HCTZ 25mg Tabs

Hydrochlorothiazide (HCTZ) is a thiazide diuretic that inhibits the reabsorption of sodium and chloride ions in the distal convoluted tubule, leading to increased excretion of sodium, chloride, and water. Triamterene is a potassium-sparing diuretic that acts directly on the distal renal tubule to inhibit the reabsorption of sodium in exchange for potassium and hydrogen ions, thereby decreasing the excretion of potassium and hydrogen ions.

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 notice any of the following symptoms, contact your doctor or seek medical help right away:

Allergic reactions: 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, or swelling of the mouth, face, lips, tongue, or throat.
Fluid and electrolyte problems: 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, or severe upset stomach or vomiting.
Acidosis (too much acid in the blood): Confusion, fast breathing, fast heartbeat, irregular heartbeat, severe stomach pain, upset stomach, or vomiting, feeling very sleepy, shortness of breath, or feeling very tired or weak.
Kidney problems: Unable to pass urine, change in urine output, blood in the urine, or significant weight gain.
Pancreatitis (pancreas problem): Severe stomach pain, severe back pain, or severe upset stomach or vomiting.
High blood sugar: Confusion, feeling sleepy, unusual thirst or hunger, frequent urination, flushing, fast breathing, or fruity-smelling breath.
Other serious symptoms: Back pain, belly pain, or blood in the urine (may indicate a kidney stone), dark urine or yellow skin and eyes, burning, numbness, or tingling sensations, restlessness, shortness of breath, chest pain or pressure, abnormal heartbeat, or erectile dysfunction.
Low blood cell counts: Unexplained bruising or bleeding, signs of infection (fever, chills, sore throat), or feeling very tired or weak.
Eye problems: Changes in vision or eye pain, which can lead to permanent vision loss if left untreated. If you experience these symptoms, contact your doctor immediately.
Skin cancer: Rarely, people taking hydrochlorothiazide have developed certain types of skin cancer. Protect your skin from the sun and have regular skin checks as advised by your doctor. If you notice any changes in the color or size of a mole, or any new or changing skin lump or growth, contact your doctor right away.

Other Side Effects

Most people do not experience serious side effects, and many have only minor or no side effects at all. However, if you notice any of the following symptoms, contact your doctor or seek medical help if they bother you or do not go away:

Constipation, diarrhea, upset stomach, vomiting, or decreased appetite
Headache
Dizziness, drowsiness, tiredness, or weakness
Increased appetite
Changes in taste
Stomach cramps

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 conditions to ensure safe treatment:

Any allergies you have, including allergies to this medication, its components, or other substances. Describe the allergic reaction you experienced, including the symptoms that occurred.
A known sulfa allergy.
Certain health conditions, such as:
+ Diabetes
+ High potassium levels
+ Kidney disease
+ Urination problems
Inability to pass urine.
Current medications, including:
+ Dofetilide
+ Lithium
+ Amiloride
+ Spironolactone
+ Other medications containing triamterene
Use of salt substitutes containing potassium, potassium-sparing diuretics, or potassium products.
* Breast-feeding: Do not breast-feed while taking this medication.

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

It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication.

When starting this medication, avoid driving and other activities that require alertness until you understand how it affects you. To minimize the risk of dizziness or fainting, get up slowly from a sitting or lying position, and be cautious when climbing stairs.

If you have diabetes (high blood sugar), consult your doctor, as this medication may increase your blood sugar levels. Monitor your blood sugar as directed by your doctor. Additionally, check your blood pressure and undergo blood work and other laboratory tests as instructed by your doctor. Be aware that this medication may interfere with certain lab tests, so inform all your healthcare providers and laboratory personnel that you are taking this drug.

If you follow a low-sodium or salt-free diet, discuss this with your doctor. Before consuming alcohol, marijuana, or other forms of cannabis, or taking prescription or over-the-counter medications that may cause drowsiness, consult your doctor.

Be aware of the potential for gout attacks, and if you have lupus, this medication can cause your condition to become active or worsen. Immediately report any new or worsening symptoms to your doctor.

This medication may increase your susceptibility to sunburn. Exercise caution when exposed to the sun, and notify your doctor if you experience easy sunburning while taking this medication.

If you experience excessive sweating, fluid loss, vomiting, or diarrhea, which can lead to low blood pressure, inform your doctor promptly.

If you are 65 years or older, use this medication with caution, as you may be more prone to side effects.

If you are pregnant or plan to become pregnant, discuss the benefits and risks of using this medication with your doctor.

• Potassium supplements
• Other potassium-sparing diuretics (e.g., spironolactone, amiloride)
• Severe renal impairment (CrCl < 30 mL/min)
• Anuria
• Pre-existing hyperkalemia

• ACE inhibitors (e.g., enalapril, lisinopril) - increased risk of hyperkalemia
• Angiotensin Receptor Blockers (ARBs) - increased risk of hyperkalemia
• NSAIDs (e.g., ibuprofen, naproxen) - may reduce diuretic/antihypertensive effect, increased risk of renal dysfunction and hyperkalemia
• Lithium - reduced renal clearance of lithium, leading to increased lithium toxicity
• Digoxin - increased risk of digoxin toxicity due to electrolyte imbalances (hypokalemia from HCTZ, though triamterene mitigates this)
• Corticosteroids - enhanced potassium depletion (from HCTZ component)
• Non-depolarizing muscle relaxants (e.g., tubocurarine) - enhanced effect due to HCTZ
• Cholestyramine/Colestipol - reduced absorption of HCTZ

• Antidiabetic agents (insulin, oral hypoglycemics) - HCTZ may decrease glucose tolerance, requiring dose adjustment
• Pressor amines (e.g., norepinephrine) - decreased arterial responsiveness to pressor amines
• Alcohol, barbiturates, narcotics - may potentiate orthostatic hypotension
• Allopurinol - increased risk of hypersensitivity reactions to allopurinol
• Amantadine - increased risk of amantadine toxicity
• Calcium salts - increased risk of hypercalcemia
• Cyclosporine - increased risk of hyperkalemia and renal dysfunction
• Methenamine - reduced efficacy of methenamine

• Not available

• Signs of hyperkalemia (muscle weakness, fatigue, bradycardia, irregular heartbeat)
• Signs of dehydration/hypovolemia (dizziness, lightheadedness, dry mouth, excessive thirst)
• Signs of hypotension (dizziness, fainting, lightheadedness upon standing)
• Signs of electrolyte imbalance (muscle cramps, nausea, vomiting, confusion, lethargy)
• Signs of gout (joint pain, swelling, redness)
• Signs of photosensitivity (severe sunburn, rash after sun exposure)

Category D. There is positive evidence of human fetal risk based on adverse reaction data from investigational or marketing experience or studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks. Thiazides cross the placental barrier and appear in cord blood. Risks include fetal or neonatal jaundice, thrombocytopenia, and possibly other adverse reactions that have occurred in adults. Triamterene has shown adverse effects in animal studies.

Not recommended. Hydrochlorothiazide is excreted in human milk and can suppress lactation. Triamterene is also likely excreted in human milk. Due to the potential for serious adverse reactions in the nursing infant, 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.

Safety and effectiveness in pediatric patients have not been established. Use is generally not recommended.

Use with caution in elderly patients. They may be more susceptible to the hypotensive and electrolyte-disturbing effects (especially hyperkalemia and hyponatremia) and may have age-related decreases in renal function, increasing the risk of adverse effects. Lower initial doses and careful monitoring are recommended.

• This combination is particularly useful for patients who develop hypokalemia with hydrochlorothiazide alone, as triamterene helps to conserve potassium.
• Instruct patients to take the medication in the morning to prevent nocturia (nighttime urination).
• Advise patients to avoid potassium-rich foods and potassium supplements unless specifically instructed by their physician, due to the risk of hyperkalemia.
• Monitor for signs of hyperkalemia (e.g., muscle weakness, fatigue, bradycardia) and hypotension (e.g., dizziness, lightheadedness).
• Patients should be advised about photosensitivity and to use sun protection.
• Caution should be exercised in patients with a history of kidney stones, as triamterene can contribute to stone formation.
• This combination is contraindicated in severe renal impairment (CrCl < 30 mL/min) due to the risk of hyperkalemia.

• Other classes of antihypertensives (e.g., ACE inhibitors, ARBs, Calcium Channel Blockers, Beta-blockers)
• Loop diuretics (e.g., Furosemide) for more potent diuresis
• Thiazide diuretics alone (e.g., Hydrochlorothiazide, Chlorthalidone)
• Potassium-sparing diuretics alone (e.g., Spironolactone, Amiloride)

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 information. 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 details about the medication, including the amount taken and the time it happened, to ensure you receive the best possible care.