Dyazide is a combination diuretic containing triamterene 50mg and hydrochlorothiazide 25mg per tablet. The two medications work together to increase the elimination of excess sodium and water while reducing the potassium loss that can occur when hydrochlorothiazide is used alone. The historical Canadian DYAZIDE formulation contained this same 50mg/25mg combination. Hydrochlorothiazide is a thiazide diuretic that acts primarily within the kidneys to reduce tubular reabsorption of sodium and chloride. This increases urinary excretion of sodium and water, producing a diuretic effect that can help decrease circulating fluid volume, lower blood pressure and reduce edema. Its diuretic activity generally begins within approximately two hours and can continue for approximately 6–12 hours.
One limitation of hydrochlorothiazide is that increased sodium excretion can also increase potassium loss, potentially resulting in hypokalemia. Triamterene is included in the combination specifically to counteract this effect. Triamterene is a potassium conserving (potassium sparing) diuretic that acts in the distal renal tubules. It decreases sodium reabsorption while reducing the exchange of sodium for potassium and hydrogen, thereby increasing sodium excretion while limiting excessive urinary potassium loss. Unlike medications such as spironolactone or eplerenone, triamterene does not primarily work by blocking aldosterone receptors. Its potassium conserving action occurs directly within the distal nephron and can occur independently of aldosterone activity.
The combination of hydrochlorothiazide and triamterene is used primarily for hypertension and edema in patients where potassium loss associated with thiazide therapy is a concern. The hydrochlorothiazide component provides most of the antihypertensive and diuretic activity, while triamterene helps maintain potassium balance.
This product provides:
- Active Ingredient: Triamterene – 50mg
- Active Ingredient: Hydrochlorothiazide – 25mg
- Quantity: 100 Tablets
- Drug Class: Potassium Sparing / Thiazide Diuretic Combination
- Dosage Form: Oral Tablet
- Common Uses: Hypertension and fluid retention (edema)
The most important safety consideration with this combination is hyperkalemia, or excessively high potassium levels. Because triamterene conserves potassium, the risk is greater in patients with impaired kidney function, diabetes, older age or those taking other medications that increase potassium. Potassium supplements, potassium containing salt substitutes and other potassium sparing medications should generally not be combined with triamterene/hydrochlorothiazide unless specifically directed and monitored by a healthcare professional.
Kidney function and serum electrolytes may require monitoring during treatment. The combination can affect potassium, sodium, magnesium, uric acid, glucose and kidney function markers, particularly in susceptible patients. Potential adverse effects can include dizziness, increased urination, dehydration, low blood pressure, nausea, weakness and electrolyte disturbances. Hydrochlorothiazide may also increase uric acid and blood glucose levels in some individuals, which can be relevant for patients with gout or diabetes.
Triamterene/hydrochlorothiazide is a prescription medication and should be used according to the directions and monitoring recommendations of a qualified healthcare professional.
