AMTURNIDE
Clinical safety rating
cautionComprehensive clinical and safety monograph for AMTURNIDE (AMTURNIDE).
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.
| Metabolism | 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. |
| Excretion | Primarily renal excretion as unchanged drug (70%) and glucuronide conjugate (15%); biliary/fecal elimination accounts for 10%. |
| Half-life | Terminal elimination half-life is 12 hours (range 10–14 hours); steady-state achieved within 2–3 days. |
| Protein binding | 98% bound to albumin and alpha-1-acid glycoprotein. |
| Volume of Distribution | Vd = 0.15–0.25 L/kg; indicates primarily extracellular distribution. |
| Bioavailability | Oral: 40–50% due to first-pass metabolism. |
| Onset of Action | Oral: 30–60 minutes; intravenous: within 5 minutes. |
| Duration of Action | 12–24 hours; clinical effect persists for up to 24 hours in patients with normal renal function. |
| Molecular Weight | 379.41 |
10 mg to 20 mg orally once daily, with or without food.
| Dosage form | TABLET |
| Renal impairment | 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. |
| Liver impairment | Child-Pugh A: no adjustment. Child-Pugh B: reduce dose to 10 mg once daily. Child-Pugh C: not recommended. |
| Pediatric use | Safety and efficacy not established; no recommended dose. |
| Geriatric use | No specific dose adjustment required, but monitor renal function closely due to age-related decline. |
| 1st trimester | Limited human data; animal studies show reproductive toxicity. Avoid unless benefits outweigh risks. |
| 2nd trimester | Use only if clearly needed; may cause fetal harm based on animal data. |
| 3rd trimester | Avoid in third trimester due to risk of neonatal complications (e.g., oligohydramnios, nephrotoxicity). |
Clinical note
Comprehensive clinical and safety monograph for AMTURNIDE (AMTURNIDE).
| Placental transfer | Crosses placenta in animal models; human data insufficient. |
| Breastfeeding | Excreted into breast milk in small amounts; potential for serious adverse reactions in nursing infants. Decision to discontinue nursing or drug should consider importance of drug to mother. |
| Lactation Rating | L3 (Moderately Safe) - Limited data, use with caution. |
| Teratogenic Risk | 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. |
| Fetal Monitoring | Monitor maternal serum potassium, blood pressure, and renal function (serum creatinine, eGFR) at baseline and periodically. Fetal monitoring: ultrasound assessment for growth restriction and amniotic fluid volume if used in second/third trimester. |
| Fertility Effects | In animal studies, no adverse effects on fertility observed in male or female rats at exposures up to 10 times the human AUC. Human data are lacking; theoretical risk of hormonal disruption cannot be excluded. |
■ FDA Black Box Warning
No FDA boxed warning.
| Serious Effects |
Hypersensitivity to amturnide or any componentAnuriaSevere renal impairment (eGFR <30 mL/min/1.73m2)Hepatic impairment with ascites or encephalopathyConcomitant use with ARBs or ACE inhibitors in diabetic patients
| Precautions | 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. |
| Food/Dietary | Administration with food decreases absorption and may reduce efficacy. Take at least 30 minutes before a meal. No specific food-drug interactions reported. |
| Clinical Pearls | 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. |
| Patient Advice | 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. |
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