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Pharmacologic class: Potassium-sparing diuretic
Therapeutic class: Diuretic
Pregnancy risk category B
FDA Box Warning
• Abnormal serum potassium elevation may occur, and is more likely in patients with renal impairment or diabetes and in elderly or severely ill patients. As uncorrected hyperkalemia may be fatal, monitor serum potassium levels frequently, especially when dosage is changed or patient has an illness that may influence renal function.
Depresses sodium resorption and potassium excretion in renal distal tubule
Capsules: 50 mg, 100 mg
Indications and dosages
Adults: 100 mg P.O. b.i.d. Do not exceed 300 mg/day.
• Concurrent antihypertensive drug therapy
• Elderly patients
• Diabetes insipidus
• Hypersensitivity to drug
• Severe hepatic disease
• Anuria, severe renal dysfunction (except nephrosis)
• Concurrent use of other potassium-sparing diuretics or potassium supplements
Use cautiously in:
• hepatic dysfunction, renal insufficiency, diabetes mellitus
• history of gout or renal calculi
• elderly or debilitated patients
• pregnant or breastfeeding patients
• children (safety not established).
• Give after meals.
• Know that drug may be used alone or as adjunct to thiazide or loop diuretics.
• Make sure patient stops taking potassium supplements before starting triamterene.
CNS: headache, fatigue, asthenia, dizziness
GI: nausea, vomiting, diarrhea, dry mouth
GU: azotemia, renal calculi
Hematologic: megaloblastic anemia, thrombocytopenia
Metabolic: hyperglycemia, hyperkalemia, metabolic acidosis
Skin: rash, photosensitivity
Drug-drug. Amantadine: increased amantadine blood level, greater risk of toxicity
Angiotensin-converting enzyme inhibitors, cyclosporine, indomethacin, potassium-sparing diuretics, potassium supplements, other potassium-containing
preparations: increased risk of hyperkalemia
Antihypertensives, nondepolarizing muscle relaxants, other diuretics, preanesthetic and anesthetic agents: potentiated effects of these drugs
Chlorpropamide: increased risk of hyponatremia
Cimetidine: increased bioavailability and decreased renal clearance of triamterene
Indomethacin: increased risk of acute renal failure
Lithium: decreased lithium clearance, greater risk of lithium toxicity
Drug-diagnostic tests. Alkali reserves, hemoglobin, platelets: decreased values
Blood urea nitrogen (BUN), creatinine, glucose, hepatic enzymes, potassium: increased levels
Liver function tests: increased values
Quinidine blood level: interference with fluorescent measurement
Drug-food. Salt substitutes containing potassium: increased risk of hyperkalemia
Drug-herbs. Gossypol, licorice: increased risk of hypokalemia
• Monitor BUN, creatinine, and electrolyte levels. Stay alert for hyperkalemia.
• Assess CBC with white cell differential.
• Advise patient to take after meals to reduce nausea.
• Instruct patient to take last daily dose in early evening to avoid nocturia.
• Teach patient to recognize and report signs and symptoms of electrolyte imbalances.
• Tell patient to avoid salt substitutes. Advise him not to use herbs without consulting prescriber.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, foods, and herbs mentioned above.
Time/action profile (diuretic effect)
|2–4 hr†||1–several days‡||7–9 hr†|
Adverse Reactions/Side Effects
Central nervous system
- erectile dysfunction
- bluish urine
Fluid and Electrolyte
- hyperkalemia (most frequent)
- blood dyscrasias
- muscle cramps
- allergic reactions
Drug-Drug interaction↑ hypotension with acute ingestion of alcohol, other antihypertensive agents, or nitrates.Use with ACE inhibitors,indomethacin,angiotensin II receptor antagonists potassium supplements, or cyclosporine ↑ risk of hyperkalemia.↓lithium excretion.Effectiveness may be ↓ by NSAIDs.↓ the effects of folic acid (leucovorin should be used).May ↑ risk of toxicity from amantadine.
- Monitor intake and output ratios and daily weight during therapy.
- If medication is given as an adjunct to antihypertensive therapy, BP should be evaluated before administering.
- Monitor response of signs and symptoms of hypokalemia (weakness, fatigue, ECG changes, arrhythmias, polyuria, polydipsia). Assess patient frequently for development of hyperkalemia (fatigue, muscle weakness, paresthesia, confusion, dyspnea, cardiac arrhythmias). Patients who have diabetes mellitus or kidney disease and elderly patients are at increased risk of developing these symptoms.
- Periodic ECGs may be considered in patients receiving prolonged therapy.
- Lab Test Considerations: Evaluate serum potassium levels prior to and routinely during therapy. Withhold drug and notify physician or other health care professional if patient becomes hyperkalemic.
- Monitor BUN, serum creatinine, and electrolytes prior to and periodically during therapy. May cause ↑ serum magnesium, uric acid, BUN, creatinine, potassium, and urinary calcium excretion levels. May also cause ↓ sodium levels.
- Discontinue potassium-sparing diuretics 3 days prior to a glucose tolerance test because of risk of severe hyperkalemia.
- Monitor platelet count and total and differential leukocyte count prior to and periodically during therapy in patients taking triamterene.
Potential Nursing DiagnosesExcess fluid volume (Indications)
- Oral: Administer in am to avoid interrupting sleep pattern for urination.
- Triamterene capsules may be opened and contents mixed with food or fluids for patients with difficulty swallowing.
- Emphasize the importance of continuing to take this medication, even if feeling well. Instruct patient to take medication at the same time each day. Take missed doses as soon as remembered unless almost time for next dose. Do not double doses.
- Caution patient to avoid salt substitutes and foods that contain high levels of potassium or sodium unless prescribed by health care professional.
- May cause dizziness. Caution patient to avoid driving or other activities requiring alertness until response to medication is known.
- Advise patient to consult with health care professional before taking any OTC or herbal decongestants, cough or cold preparations, or appetite suppressants concurrently with this medication because of potential for increased BP.
- Advise patients taking triamterene to use sunscreen and protective clothing to prevent photosensitivity reactions.
- Instruct patient to notify health care professional of medication regimen prior to treatment or surgery.
- Inform patient that triamterene may cause bluish-colored urine.
- Advise patient to notify health care professional if muscle weakness or cramps; fatigue; or severe nausea, vomiting, or diarrhea occurs.
- Emphasize the need for follow-up exams to monitor progress.
- Hypertension: Reinforce need to continue additional therapies for hypertension (weight loss, restricted sodium intake, stress reduction, moderation of alcohol intake, regular exercise, and cessation of smoking). Medication helps control but does not cure hypertension.
- Teach patient and family the correct technique for checking BP weekly.
- Increase in diuresis and decrease in edema while maintaining appropriate serum potassium level.
- Decrease in BP.
- Prevention of hypokalemia in patients taking diuretics.