Moduretic is most commonly used to manage high blood pressure (hypertension) and to treat fluid retention (edema) associated with heart failure, liver cirrhosis, or nephrotic syndrome. The hydrochlorothiazide component promotes sodium and water excretion by acting on the distal tubule, which lowers blood volume and blood pressure. The amiloride component spares potassium by blocking sodium channels in the collecting duct, helping prevent thiazide-induced hypokalemia. Because of this complementary action, Moduretic is often selected when clinicians want the benefits of a thiazide diuretic but want to reduce the need for separate potassium supplements. It may also be used off-label in specific cases of resistant hypertension where combined diuretic effects are advantageous.
Moduretic dosing is individualized based on the condition being treated, patient age, kidney function, and response to therapy. Typical adult regimens commonly start with one tablet once daily in the morning to reduce nocturia; available formulations pair amiloride and HCTZ in fixed ratios. Your prescriber may adjust the dose gradually to achieve desired blood pressure control and diuresis. Because the drug increases urine output, taking it early in the day is practical. Always follow the specific instructions provided by your healthcare professional and the dispensing label. Do not double doses to make up for a missed dose and consult your provider before changing dose frequency. Regular follow-up visits with laboratory monitoring of electrolytes, kidney function, and blood pressure are integral to safe dosing.
Before starting Moduretic, clinicians typically check baseline serum electrolytes (potassium, sodium), creatinine and estimated glomerular filtration rate (eGFR), and uric acid. Use with caution in patients with impaired renal function because the risk of hyperkalemia and accumulation increases as renal clearance falls. Monitor closely in people with diabetes—thiazides can elevate blood glucose and affect glycemic control. Thiazide diuretics may also increase serum uric acid and precipitate gout in susceptible individuals. Be cautious with elderly patients who are more prone to volume depletion and orthostatic hypotension. Photosensitivity reactions can occur with thiazide components, so advise sun protection. Inform your provider about pregnancy or breastfeeding; diuretics are generally used with caution during pregnancy and only when clearly indicated.
Moduretic should not be used in patients with anuria or severe renal impairment where diuretic response is negligible or risks are elevated. It is contraindicated in individuals with known hyperkalemia, since amiloride can raise potassium further and lead to dangerous cardiac arrhythmias. Hypersensitivity to hydrochlorothiazide or other sulfonamide-derived drugs is another clear contraindication. Concurrent use of other potassium-sparing diuretics or potassium supplements without close monitoring is generally contraindicated due to the additive risk of hyperkalemia. Always disclose all medical conditions to the prescriber to ensure Moduretic is appropriate and safe for you.
Common side effects include increased urination, dizziness or lightheadedness (particularly when standing), and mild gastrointestinal upset. Because hydrochlorothiazide can cause electrolyte loss, patients may experience hyponatremia or low chloride; however, the amiloride component offsets potassium loss and can lead instead to high potassium (hyperkalemia) in some people. Other potential effects include elevated blood glucose, increased uric acid with possible gout flares, and photosensitivity reactions. Less common but serious adverse events include severe hypotension, pronounced electrolyte disturbances, and kidney function impairment. Seek medical attention if you experience muscle weakness, irregular heartbeat, severe dizziness, fainting, or signs of dehydration.
Moduretic interacts with several medication classes that can alter electrolyte balance or renal function. Combining Moduretic with ACE inhibitors, angiotensin receptor blockers (ARBs), or direct renin inhibitors increases the risk of hyperkalemia and requires close potassium monitoring. Concurrent use with potassium supplements or other potassium-sparing drugs (e.g., amiloride-containing combinations, spironolactone, eplerenone) is generally discouraged. Nonsteroidal anti-inflammatory drugs (NSAIDs) can blunt diuretic response and raise the risk of renal impairment. Lithium levels can rise when taken with diuretics due to decreased lithium clearance—monitor lithium closely or avoid coadministration. Thiazides can also potentiate the glucose-raising effects of antidiabetic drugs and increase digoxin toxicity risk by altering electrolytes. Always review all prescription, over-the-counter medications, and supplements with your provider to avoid harmful interactions.
If you miss a dose of Moduretic, take it as soon as you remember unless it is close to the time for your next scheduled dose. Do not take two doses at once to make up for a missed dose. Because Moduretic affects fluid balance, maintaining an even dosing schedule helps stabilize blood pressure and electrolyte levels. If you frequently forget doses, consider using a pill organizer, smartphone reminders, or asking a family member to help with adherence. If you miss several doses or have concerns about blood pressure control after a missed dose, contact your healthcare provider for advice rather than adjusting the dose on your own.
An overdose of Moduretic can lead to severe dehydration, dangerously low blood pressure, and significant electrolyte disturbances—particularly hyperkalemia from amiloride and disturbances in sodium and chloride from hydrochlorothiazide. Symptoms of overdose may include extreme dizziness, fainting, irregular heartbeat, muscle weakness, confusion, severe nausea or vomiting, and decreased urine output. Management is supportive and tailored to the specific abnormalities: stabilize airway and circulation, monitor cardiac rhythm, correct electrolyte imbalances (for example, treating hyperkalemia urgently if present), and consider intravenous fluids for volume depletion. In severe cases with refractory hyperkalemia or renal failure, hemodialysis may be necessary. Immediate medical attention is essential in any suspected overdose.
Store Moduretic at room temperature, away from excess heat and moisture—avoid keeping it in the bathroom. Keep the bottle tightly closed and store the medication out of reach of children and pets. Dispose of expired or unused medication according to local regulations or pharmacy take-back programs; do not flush medications down the toilet unless instructed. Keep an updated list of all medications and bring it to medical appointments so prescribers and pharmacists can check for interactions. Proper storage helps preserve potency and prevents accidental ingestion by others.
In the United States, Moduretic is a prescription medication due to its potential for serious electrolyte and kidney effects, and responsible prescribing typically requires a clinical evaluation. However, Southwest Georgia Regional Medical Center offers a legal, structured pathway that enables eligible patients to obtain Moduretic without a traditional standalone prescription slip. This is accomplished through supervised clinical services such as telemedicine consultations, nurse practitioner or physician-led assessments, and standing orders where permitted by state regulations. Patients undergo an evaluation that includes medical history review, baseline labs (electrolytes, kidney function), and individualized counseling about risks and monitoring. If Moduretic is deemed appropriate, the center can dispense the medication directly or arrange pharmacist-managed dispensing under institutional protocols.
This approach is designed to maintain safety and regulatory compliance while improving access: it is not an over-the-counter sale. Patients must meet eligibility criteria, consent to monitoring, and often agree to periodic laboratory follow-up. The service reduces barriers to treatment for those who need timely medication but may lack easy access to a primary care appointment. If you are considering this option, contact Southwest Georgia Regional Medical Center’s outpatient pharmacy or clinical services to learn about the evaluation steps, any associated fees, and what monitoring will be required to ensure safe use of Moduretic. Remember: responsible use under medical supervision is essential to minimize risks and maximize therapeutic benefit.
Moduretic is a combination diuretic containing triamterene (a potassium-sparing diuretic) and hydrochlorothiazide (a thiazide diuretic). The hydrochlorothiazide promotes salt and water loss by the kidneys while triamterene reduces potassium loss, so together they lower blood volume and blood pressure while helping prevent excessive potassium depletion.
Moduretic is commonly prescribed for hypertension (high blood pressure) and edema (fluid retention) associated with heart failure, liver disease, or certain kidney disorders. It is used when a clinician wants thiazide diuresis but also wants to reduce the risk of hypokalemia.
Moduretic is available in formulations combining triamterene and hydrochlorothiazide, for example 37.5 mg triamterene with 25 mg hydrochlorothiazide. Dosing depends on the condition, patient response, and kidney function; follow the prescriber's instructions and do not adjust dose without consulting a clinician.
Common side effects include dizziness or lightheadedness (especially when standing), increased urination, gastrointestinal upset, headache, and fatigue. Electrolyte changes such as high potassium (hyperkalemia) or low sodium (hyponatremia) and metabolic effects like increased uric acid or blood glucose can also occur.
Serious risks include hyperkalemia (which can cause cardiac arrhythmias), significant dehydration or low blood pressure, kidney dysfunction, and in rare cases triamterene-related crystalluria or kidney stones. Allergic reactions and severe skin reactions are possible though uncommon. Seek immediate care for chest pain, fainting, severe weakness, or signs of allergic reaction.
Moduretic is contraindicated in patients with known hyperkalemia, severe renal impairment or anuria, and in people with hypersensitivity to sulfonamide-derived drugs. It should be avoided or used cautiously in pregnancy and breastfeeding unless specifically recommended by a clinician.
Triamterene reduces urinary potassium loss, which can help prevent hypokalemia from the thiazide, but it can also cause hyperkalemia. Regular monitoring of serum electrolytes (potassium, sodium) and renal function is recommended, especially when starting therapy or changing doses and when used with other drugs that affect potassium.
Moduretic can interact with ACE inhibitors, ARBs, potassium supplements, potassium-sparing drugs, and NSAIDs, increasing the risk of hyperkalemia or renal dysfunction. It can raise lithium levels and interact with certain diabetes medications and antiarrhythmics. Always review all medications, supplements, and salt substitutes with your clinician.
Moduretic is generally not recommended during pregnancy due to risks associated with diuretics and potential electrolyte disturbances; discuss alternative options with your obstetrician. Breastfeeding mothers should consult their clinician, as components can pass into breast milk and may affect the infant.
Some diuretic effect may be noticed within hours, but full antihypertensive benefits may take several weeks as the body reaches a new fluid and electrolyte balance. Symptom relief for mild edema can be seen sooner; follow-up monitoring is important to assess response and safety.
Yes. Maintain adequate hydration unless otherwise advised, avoid potassium-rich salt substitutes or supplements unless instructed, limit excessive alcohol which can worsen blood pressure and dizziness, and be cautious with heat or strenuous exercise due to dehydration risk. Monitor blood pressure and report symptoms like excessive dizziness, muscle weakness, or irregular heartbeat.
Take Moduretic exactly as prescribed, usually in the morning to avoid nocturnal urination. Taking it with food may reduce stomach upset. Stand up slowly to minimize orthostatic dizziness and avoid sudden position changes. Do not skip monitoring appointments or laboratory tests.
If you miss a dose, take it as soon as you remember unless it is near the time for your next dose. Do not double up to make up a missed dose. If unsure, contact your pharmacist or prescriber for guidance.
Thiazide diuretics like hydrochlorothiazide can cause modest increases in blood glucose, cholesterol, and triglyceride levels in some patients. These changes are usually mild but should be monitored, especially in people with diabetes or dyslipidemia.
Baseline labs should include serum electrolytes, creatinine, and possibly uric acid and glucose. Repeat testing is typically done after initiation or dose changes (within 1–2 weeks) and periodically thereafter based on clinical judgment, renal function, and concomitant medications.
Hydrochlorothiazide can increase sensitivity to sunlight, leading to sunburn-like reactions in some people. Use sun protection and avoid excessive sun exposure. If you develop a severe rash or blistering, seek medical attention.
Store Moduretic at room temperature away from moisture, heat, and direct light. Keep medication in its original container and out of reach of children. Discard expired medication safely.
Triamterene has been associated in rare cases with crystalluria and formation of kidney stones due to low solubility; adequate fluid intake and monitoring reduces risk. If you have a history of kidney stones, discuss risks and alternatives with your clinician.
Seek immediate care for signs of severe hyperkalemia (muscle weakness, irregular heartbeat), fainting or severe dizziness, very low urine output, severe rash, difficulty breathing, or sudden swelling. These may signal serious adverse effects.
Both combinations pair a potassium-sparing diuretic with hydrochlorothiazide to balance potassium. Amiloride tends to be less likely than triamterene to precipitate in urine or form crystals, whereas triamterene has been linked historically to crystalluria. Clinical efficacy for blood pressure control is broadly similar; selection often depends on tolerability and patient-specific factors.
Both triamterene and spironolactone can cause hyperkalemia, but spironolactone (an aldosterone antagonist) typically has a stronger potassium-retaining effect and is more commonly associated with clinically significant hyperkalemia, especially in patients with renal impairment or when combined with ACE inhibitors/ARBs. Monitoring is required with either drug.
Combining hydrochlorothiazide with triamterene provides similar antihypertensive effects to hydrochlorothiazide alone but reduces the risk of hypokalemia. HCTZ alone may cause more potassium loss and related symptoms; the combination aims to mitigate that side effect while maintaining diuretic efficacy.
Chlorthalidone is another thiazide-like diuretic with a longer half-life and evidence of potent and sustained blood pressure lowering; some studies suggest greater cardiovascular outcome benefits compared to hydrochlorothiazide. Moduretic contains hydrochlorothiazide, so clinicians may favor chlorthalidone for certain patients, though chlorthalidone is not combined with triamterene in the same fixed-dose product.
Loop diuretics (e.g., furosemide) are more potent for rapid mobilization of fluid and are preferred for severe edema or significant renal impairment. Moduretic (a thiazide-based combination) is better suited for mild-to-moderate edema and hypertension with preserved renal function.
Not interchangeable on a milligram-to-milligram basis because Moduretic intentionally combines two agents to balance effects: triamterene alone lacks the robust thiazide antihypertensive effect, while hydrochlorothiazide alone increases potassium loss. Switching requires clinical judgment to preserve therapeutic goals and manage electrolyte risks.
Spironolactone provides mortality benefit in certain heart failure populations due to aldosterone antagonism and is often preferred for advanced heart failure. Moduretic may help with fluid control in milder cases, but it does not replace the neurohormonal benefits of spironolactone; choice depends on clinical indication and patient-specific factors.
All potassium-sparing combinations, including Moduretic (triamterene/HCTZ) and amiloride/HCTZ, increase hyperkalemia risk when combined with ACE inhibitors. The degree of interaction is similar in principle, so clinicians monitor potassium closely irrespective of which potassium-sparing agent is used.
Moduretic may be preferred when a clinician wants thiazide diuresis but needs to reduce risk of hypokalemia—such as in patients prone to low potassium or on other medications that lower potassium. It may be less suitable for patients with significant renal impairment, hyperkalemia risk, or a history of kidney stones.
Choice depends on the therapeutic goal: eplerenone and spironolactone are aldosterone antagonists with specific indications (e.g., heart failure with reduced ejection fraction, primary aldosteronism) and certain benefits on mortality. Triamterene (in Moduretic) is mainly used to counteract thiazide-induced potassium loss. Safety profiles, drug interactions, and the underlying condition guide selection.
Switching may reduce occurrences of low potassium-related symptoms (muscle cramps, weakness) due to triamterene’s potassium-sparing effect. Patients should still have electrolytes checked because triamterene can raise potassium. Blood pressure effects should be monitored to ensure continued control.
Spironolactone can cause anti-androgenic side effects like gynecomastia, impotence, and menstrual irregularities due to steroid hormone receptor interactions. Triamterene (in Moduretic) typically lacks these hormonal side effects, making Moduretic preferable when such adverse effects are a concern.
It can be combined, but the combination increases the risk of hyperkalemia and renal function changes. If combined with ACE inhibitors or ARBs, clinicians usually monitor potassium and renal function more frequently and adjust therapy as needed.
Assess baseline renal function and potassium, avoid concomitant potassium supplements or unnecessary potassium-sparing agents, and review interacting drugs. Schedule early follow-up labs after initiation and educate patients to avoid high-potassium salt substitutes and to report symptoms like muscle weakness or palpitations.
Fixed-dose combinations like Moduretic improve adherence by reducing pill burden and provide a predictable balance between diuresis and potassium conservation. They can simplify therapy when both effects are desired rather than prescribing two separate agents.
Cost varies by region, insurance coverage, and availability of generics. Generic triamterene-HCTZ combinations and standalone generic diuretics often provide cost-effective options. Check local formularies and discuss affordability with a pharmacist or prescriber.
Avoid potassium-containing salt substitutes or supplements unless directed, be cautious with NSAIDs (which can blunt diuretic effect and impair renal function), and inform providers about all OTC remedies and herbal supplements to prevent interactions and electrolyte disturbances.