[2-butyl-5-chloro-3-[[4-[2-(2H-tetrazol-5-yl)phenyl]phenyl]methyl]- 3H-imidazol-4-yl]methanol

6-chloro-3,4-dihydro-2H-1,2,4-benzothiadiazine-7-sulfonamide 1,1-dioxide

Losartan能快速由胃腸道吸收，並在1小時內能達血中最高濃度；本品主要經由肝臟的cytochrome P450酵素代謝，大部分由膽汁排出，一部分由尿液排出，其Half-life在1.5∼2.5小時，主要的活性代謝物的Half-life約在6∼9小時。

口服單一劑量的hydrochlorothiazide之後吸收快速(t½約2小時)，懸浮劑及錠劑兩種劑型吸收的特性相似，分佈及排除的動力學為雙指數衰減模式，其最終的半衰期為6∼15小時。

Losartan potassium Fluconazole
Losartan plasma levels may be elevated, increasing the antihypertensive and adverse effects.

Lithium
Plasma levels of lithium may be elevated, increasing the pharmacologic and adverse effects.

Rifamycins (eg, rifampin)
Losartan plasma levels may be reduced, decreasing the antihypertensive effects.

Potassium-sparing diuretics (eg, spironolactone), potassium supplements, salt substitutes containing potassium
May lead to increased serum potassium.

Hydrochlorothiazide Alcohol, barbiturates, narcotics
Increased risk of orthostatic hypotension.

Antidiabetic agents
Dose adjustments of antidiabetic agent may be needed.

Antihypertensives
Actions of other antihypertensive agents may be potentiated.

Cholestyramine, colestipol resins
Absorption of hydrochlorothiazide may be impaired.

ACTH, corticosteroids
Increased risk of electrolyte depletion (eg, hypokalemia).

Pressor amines (eg, norepinephrine)
Decreased response to pressor amine.

Nondepolarizing skeletal muscle relaxants (eg, turbocurarine)
Responsiveness to muscle relaxant may be increased.

Lithium
Plasma levels of lithium may be elevated, increasing the risk of toxicity.

NSAIDs
Antihypertensive, diuretic, and natriuretic effects of hydrochlorothiazide may be reduced.

臨床試驗數據顯示，相較於使用單一作用於RAAS之藥品，合併使用ACEIs、ARBs或含aliskiren成分藥品來雙重阻斷RAAS，不良反應【例如：低血壓、高鉀血症及腎功能下降（包括急性腎衰竭）】之發生率較高。

合併使用本品及含aliskiren成分藥品於糖尿病患或腎功能不全患者 (GFR < 60 ml/min/1.73 m²)。

雙重阻斷腎素－血管昇壓素－醛固酮系統（renin-angiotensin-aldosterone system, RAAS）：有證據顯示，合併使用ACEIs、ARBs或含aliskiren成分藥品會增加低血壓、高鉀血症及腎功能下降（包括急性腎衰竭）之風險，故不建議合併使用ACEIs、ARBs或含aliskiren成分藥品來雙重阻斷RAAS，若確有必要使用雙重阻斷治療，應密切監測患者之腎功能、電解質及血壓。ACEIs及ARBs不應合併使用於糖尿病腎病變患者。