triamterene (Dyrenium)
Jump to navigation
Jump to search
Introduction
Tradename: Dyrenium.
Indications
- management of edema & hypertension
- hypokalemia[3]
Contraindications
- renal insufficiency, avoid eGFR < 30 mL/min
Dosage
Tabs: 50, 100 mg.
Pharmacokinetics
- full therapeutic effects may not be seen for several days
- absorption is variable depending upon formulation
- drug undergoes extensive 1st pass metabolism to an active metabolite
- 50-55% bound to plasma proteins
- congugate is 91% bound to plasma proteins
- both parent & conjugate are filtered & secreted renally
- elimination 1/2life is 4.1 hours & 3.1 hours for conjugate
- 1/2life is prolonged in the elderly & in patients with cirrhosis
elimination via liver
elimination via kidney
Adverse effects
- hyperkalemia, especially in patients with renal failure
- nausea/vomiting
- diarrhea
- increase in blood urea nitrogen (BUN)
- metabolic acidosis (rare)
- megaloblastic anemia (rare)
Drug interactions
- hyperkalemia potentiated by concomitant use of ACE inhibitors, NSAIDs, diabetes
- NSAIDs can cause adverse effects of renal function & decrease diuretic effect
- drug interaction(s) SGLT2 inhibitors (flozins) with diuretics
- drug interaction(s) of diuretics in combination with Zn+2
- drug interaction(s) of antiarrhythmic agents in combination with diuretics
- drug interaction(s) of calcium channel blockers with diuretics
- drug interaction(s) of spironolactone with potassium-sparing diuretics
- drug interaction(s) of ACE inhibitors with potassium-sparing diuretics
- drug interaction(s) of diuretics with angiotensin II receptor antagonists
- drug interaction(s) of diuretics with ACE inhibitors
- drug interaction(s) of NSAIDs, diuretics & angiotensin II receptor antagonists
- drug interaction(s) of NSAIDs, diuretics & ACE inhibitors
- drug interaction(s) of NSAIDs & antihypertensives
Laboratory
Mechanism of action
- K+ sparing diuretic
- acts directly on distal renal tubule & collecting duct to inhibit reabsorption of Na+
- Na+, Cl-, Ca+2, & possibly HCO3- is increased
- K+ & possibly Mg+2 excretion is decreased