Comparative Pharmacology
Head-to-head clinical analysis: AMTURNIDE versus AZOR.
Peer-Reviewed Evidence
Head-to-head clinical analysis: AMTURNIDE versus AZOR.
AMTURNIDE vs AZOR
Head-to-head clinical comparison of therapeutic indices and safety profiles.
AMTURNIDE is a combination of amiloride, a potassium-sparing diuretic that inhibits sodium reabsorption in the distal convoluted tubule and collecting duct, and hydrochlorothiazide, a thiazide diuretic that inhibits sodium chloride reabsorption in the distal convoluted tubule. The combination produces additive diuretic and antihypertensive effects with reduced potassium loss.
Amlodipine is a dihydropyridine calcium channel blocker that inhibits calcium ion influx across cardiac and vascular smooth muscle cells, causing vasodilation and reduced peripheral vascular resistance. Olmesartan is an angiotensin II receptor blocker (ARB) that selectively blocks AT1 receptors, inhibiting vasoconstriction and aldosterone secretion.
HypertensionEdema due to congestive heart failureEdema due to hepatic cirrhosisEdema due to nephrotic syndromeEdema due to corticosteroid or estrogen therapy
Treatment of hypertension, alone or with other antihypertensive agents
10 mg to 20 mg orally once daily, with or without food.
AZOR is a combination of amlodipine and olmesartan. Typical adult dose: one tablet orally once daily. Available strengths: amlodipine/olmesartan 5mg/20mg, 5mg/40mg, 10mg/20mg, 10mg/40mg. Dose can be titrated based on blood pressure response.
None Documented
None Documented
Terminal elimination half-life is 12 hours (range 10–14 hours); steady-state achieved within 2–3 days.
Amlodipine: 30-50 h (terminal); supports once-daily dosing. Olmesartan: 10-15 h (terminal); once-daily dosing effective
Amiloride is not metabolized and is excreted unchanged in the urine. Hydrochlorothiazide is not extensively metabolized; the majority is excreted unchanged in the urine via renal tubular secretion.
Amlodipine is extensively metabolized in the liver via CYP3A4 to inactive metabolites. Olmesartan is metabolized by the liver to a minor extent; it undergoes glucuronidation and some oxidation by CYP2C9.
Primarily renal excretion as unchanged drug (70%) and glucuronide conjugate (15%); biliary/fecal elimination accounts for 10%.
Renal: 90% (amlodipine: 60% as metabolites, 10% as parent; olmesartan: 35-50% as parent via urine, rest in feces via bile). Fecal: 10%
98% bound to albumin and alpha-1-acid glycoprotein.
Amlodipine: ~93% bound to plasma proteins. Olmesartan: >99% bound to albumin
Vd = 0.15–0.25 L/kg; indicates primarily extracellular distribution.
Amlodipine: 21 L/kg (large, extensive tissue distribution). Olmesartan: 17-30 L (approximate, Vd not typically reported per kg); distribution into tissues
Oral: 40–50% due to first-pass metabolism.
Oral: amlodipine 64-90% (high, first-pass ~10%); olmesartan 26% (oral, complete absorption reduced by first-pass ester hydrolysis)
eGFR ≥30 mL/min/1.73 m²: no adjustment. eGFR 15-29 mL/min/1.73 m²: reduce dose to 10 mg once daily. eGFR <15 mL/min/1.73 m² or dialysis: not recommended.
No dose adjustment is required for mild to moderate renal impairment (CrCl ≥30 mL/min). For severe renal impairment (CrCl <30 mL/min), use with caution; maximum dose of olmesartan is 20 mg once daily. Monitor serum potassium and creatinine.
Child-Pugh A: no adjustment. Child-Pugh B: reduce dose to 10 mg once daily. Child-Pugh C: not recommended.
No dose adjustment for mild hepatic impairment (Child-Pugh A). For moderate to severe hepatic impairment (Child-Pugh B or C), amlodipine half-life is prolonged; initiate with amlodipine 2.5 mg and olmesartan 10 mg, and titrate slowly. Use caution; contraindicated in severe hepatic impairment with cholestasis? Not specifically contraindicated but not recommended.
Safety and efficacy not established; no recommended dose.
Safety and efficacy in pediatric patients <18 years have not been established. Not recommended for use in children.
No specific dose adjustment required, but monitor renal function closely due to age-related decline.
In elderly patients (≥65 years), start with the lowest available dose (amlodipine/olmesartan 5/20 mg daily) and titrate slowly due to increased sensitivity and potential for hypotension. Monitor renal function and electrolytes closely in geriatric patients.
No FDA boxed warning.
None
["Hyperkalemia: Risk is increased in patients with renal impairment, diabetes, or elderly. Monitor serum potassium levels.","Hypersensitivity reactions: May occur with sulfonamide derivatives (hydrochlorothiazide).","Acute angle-closure glaucoma: Has been reported with sulfonamide derivatives.","Electrolyte imbalances: Including hyponatremia, hypochloremia, hypomagnesemia, and hypokalemia.","Renal impairment: Use with caution; may precipitate azotemia.","Hepatic impairment: Use with caution; may precipitate hepatic encephalopathy.","Diabetes: Thiazides may impair glucose tolerance.","Gout: Thiazides may increase serum uric acid levels.","SLE exacerbation: Thiazides may exacerbate systemic lupus erythematosus."]
["Fetal toxicity (detectable in second and third trimesters): drugs acting on the renin-angiotensin system can cause oligohydramnios, fetal renal dysfunction, and death","Avoid concomitant use with aliskiren in patients with diabetes","Hypotension in volume/depleted patients","Increased angina or myocardial infarction with calcium channel blockers, particularly with severe obstructive coronary artery disease","Peripheral edema is dose-dependent and more common with amlodipine","Hepatic impairment: lower starting dose","Renal artery stenosis","Electrolyte imbalances"]
["Anuria","Acute or chronic renal insufficiency","Severe renal impairment (eGFR <30 mL/min)","Hyperkalemia (serum potassium >5.5 mEq/L)","Hypersensitivity to amiloride, hydrochlorothiazide, or sulfonamide-derived drugs","Concomitant use with potassium-sparing diuretics, potassium supplements, or other drugs that increase potassium (e.g., ACE inhibitors, ARBs)"]
["Hypersensitivity to any component","Do not use with aliskiren in patients with diabetes"]
Data Pending Review
Data Pending Review
Administration with food decreases absorption and may reduce efficacy. Take at least 30 minutes before a meal. No specific food-drug interactions reported.
Avoid grapefruit and grapefruit juice due to CYP3A4 inhibition increasing amlodipine levels. No other significant food interactions.
FDA Pregnancy Category C. In animal studies, amturnide (finerenone) caused embryofetal toxicity (reduced fetal body weight, delayed ossification, and increased resorptions) at maternal toxic doses. There are no adequate human studies. Risk cannot be ruled out; use only if potential benefit justifies potential risk. First trimester: unknown risk. Second/third trimester: potential for fetal renal effects due to mineralocorticoid receptor blockade.
Pregnancy Category D. First trimester: Potential for fetal toxicity (oligohydramnios, fetal/neonatal renal dysfunction, skull hypoplasia) due to olmesartan action on renin-angiotensin system; avoid use. Second trimester: Continued risk of fetal renal impairment and oligohydramnios. Third trimester: High risk of fetal/neonatal renal failure, hypotension, hyperkalemia, and skull ossification defects; contraindicated.
No data on presence in human milk. Finerenone and its metabolites are excreted in rat milk. M/P ratio not determined in humans. Due to potential for serious adverse reactions in nursing infants (e.g., hyperkalemia, hypotension), breastfeeding is not recommended during therapy.
No human data on olmesartan or amlodipine excretion in breast milk. Amlodipine transfers into human milk with M/P ratio approximately 0.5-1.5; risk to infant unknown. Due to potential for adverse effects (hypotension, renal impairment), use is not recommended. Alternative antihypertensives with more safety data should be considered.
No specific dose adjustments established. Pharmacokinetics may be altered due to increased volume of distribution and renal plasma flow; however, no data exist. Use lowest effective dose if essential. Monitor for hyperkalemia and hypotension, which may require dose reduction or discontinuation.
Not applicable; use is contraindicated in pregnancy. No dose adjustment can mitigate fetal risk; alternative agents (e.g., labetalol, nifedipine) are preferred. If inadvertently used, discontinue as soon as pregnancy is detected.
Category C
Category C
AMTURNIDE is a first-in-class guanylate cyclase-C receptor agonist for irritable bowel syndrome with constipation (IBS-C). It increases intestinal fluid secretion and transit without significant systemic absorption. Onset of action may occur within 24 hours, but full response may take 2-4 weeks. Avoid in patients with known or suspected mechanical gastrointestinal obstruction. Dose adjustment not required for renal or hepatic impairment.
AZOR is a fixed-dose combination of amlodipine (calcium channel blocker) and olmesartan (angiotensin II receptor blocker). Monitor serum potassium and creatinine, especially in renal impairment or concomitant ACE inhibitor use. Avoid in pregnancy (use effective contraception). May cause dizziness or peripheral edema, often dose-related.
Take once daily on an empty stomach at least 30 minutes before the first meal of the day.Do not crush or chew the capsule; swallow whole with water.Common side effects include diarrhea, abdominal pain, and flatulence; diarrhea is most frequent.Seek medical attention if you experience severe or bloody diarrhea.Notify your doctor if you are pregnant, breastfeeding, or have a history of bowel obstruction.
Take exactly as prescribed, usually once daily, with or without food.Avoid grapefruit or grapefruit juice as it can increase amlodipine levels.Notify your doctor if you become pregnant or plan to become pregnant.Do not stop taking suddenly; consult your doctor before discontinuing.Report lightheadedness, fainting, or significant swelling in your ankles or feet.Use caution when driving or operating machinery until you know how this medication affects you.