高血壓 (diuretics) 高血壓 (ARB) 利尿劑 (thiazide) Cerebrovascular accident, In hypertensive patients with left ventricular hypertrophy; Prophylaxis
Hypertension

[Losartan] Losartan is a nonpeptide angiotensin II receptor antagonist with high affinity and selectivity for the AT(1) receptor. Losartan blocks the vasoconstrictor and aldosterone-secreting effects of angiotensin II by inhibiting the binding of angiotensin II to the AT 1 receptor. AT 1 receptor blockade results in an increase in plasma renin activity (PRA) followed by increases in plasma angiotensin II concentration.The potential clinical consequences of these increases are not clear. Angiotensin II agonist effects have not been demonstrated.

[Hydrochlorothiazide] Hydrochlorothiazide is a thiazide diuretic. Thiazide diuretics increase urinary excretion of sodium and water by inhibiting sodium reabsorption in the early distal tubule. The diuretic action of hydrochlorothiazide decreases plasma volume, resulting in increases in plasma renin activity, increases in aldosterone secretion, increases in urinary potassium loss, and decreases in serum potassium. Since the renin-aldosterone link is mediated by angiotensin II, coadministration of losartan tends to reverse the potassium loss associated with hydrochlorothiazide.

[Absorption]
- Losartan - Well-absorbed; Bioavailability: 33%

[Metabolism]
- Losartan - Hepatic: first pass / Active metabolite: carboxylic acid metabolite
- Hydrochlorothiazide - not metabolized

[Excretion]
- Losartan - Fecal: 60% / Renal: 35%, 4% unchanged and 6% active metabolite
- Hydrochlorothiazide - Renal

[Elimination Half Life]
- Losartan - 2 hr
- Hydrochlorothiazide - 5.6 to 14.8 hr

Anuria
Coadministration with aliskiren in patients with diabetes
Hypersensitivity to any component of the product

D [FDA]

Infant risk cannot be ruled out. [MDX]

[Central nervous system] Dizziness (6%)
[Neuromuscular & skeletal] Back pain (2%)
[Respiratory] Upper respiratory tract infection (6%)

[Cerebrovascular accident, In hypertensive patients with left ventricular hypertrophy; Prophylaxis]
Initial (not adequately controlled on losartan 50 mg): Hyzaar 50/12.5 mg PO QD; may increase to Losartan 100 mg/Hydrochlorothiazide 12.5 mg QD, followed by Losartan 100 mg/Hydrochlorothiazide 25 mg QD as needed.
Add other antihypertensive agents if further blood pressure reduction is required.

[Hypertension]
Initial: Hyzaar 50/12.5 mg PO QD; may increase after 3 weeks to MAX Hyzaar 100/25 mg QD
Initial (not controlled on Losartan 100 mg/day): Losartan 100 mg/Hydrochlorothiazide 12.5 mg PO QD; may increase after 3 weeks to MAX Losartan 100 mg/Hydrochlorothiazide 25 mg QD
Initial (not controlled on Hydrochlorothiazide 25 mg/day, or controlled but experiencing hypokalemia): Hyzaar 50/12.5 mg PO QD; may increase after 3 weeks to MAX Hyzaar 100/25 mg QD

Safety and effectiveness not established in pediatric patients.

Nil.

Use for initial therapy not recommended as the starting dose is not available in the combination tablets.

Store at controlled room temperature, 25 degrees C.
Keep container tightly closed and protect from light.