- Accession Number
A quinazoline-sulfonamide that is considered a thiazide-like diuretic which is long-acting so useful in chronic renal failure. It also tends to lower blood pressure and increase potassium loss.
- Small Molecule
- Average: 365.835
- Chemical Formula
- External IDs
- SR 720-22
For the treatment of hypertension, alone or in combination with other antihypertensive drugs of a different class.
- Associated Conditions
- Contraindications & Blackbox Warnings
Learn about our commercial Contraindications & Blackbox Warnings data.Learn More
Metolazone is a quinazoline diuretic, with properties generally similar to the thiazide diuretics. A proximal action of metolazone has been shown in humans by increased excretion of phosphate and magnesium ions and by a markedly increased fractional excretion of sodium in patients with severely compromised glomerular filtration. This action has been demonstrated in animals by micropuncture studies.
- Mechanism of action
The actions of metolazone result from interference with the renal tubular mechanism of electrolyte reabsorption. Metolazone acts primarily to inhibit sodium reabsorption at the cortical diluting site and to a lesser extent in the proximal convoluted tubule. Sodium and chloride ions are excreted in approximately equivalent amounts. The increased delivery of sodium to the distal tubular exchange site results in increased potassium excretion. Metolazone does not inhibit carbonic anhydrase. The antihypertensive mechanism of action of metolazone is not fully understood but is presumed to be related to its saluretic and diuretic properties.
Target Actions Organism ASolute carrier family 12 member 3inhibitor Humans
Peak blood levels are obtained within 2 to 4 hours of oral administration. The rate and extent of absorption are formulation dependent.
- Volume of distribution
- Not Available
- Protein binding
50-70% bound to erythrocytes, up to 33% bound to plasma proteins, 2-5% of the drug in circulation is unbound
Not substantially metabolized. 70-95% is excreted unchanged in urine via glomerular filtration and active tubular secretion. Undergoes enterohepatic recycling.
- Route of elimination
Most of the drug is excreted in the unconverted form in the urine.
Approximately 14 hours.
- Not Available
- Adverse Effects
Learn about our commercial Adverse Effects data.Learn More
Symptoms of overdose include difficulty breathing, dizziness, dizziness on standing up, drowsiness, fainting, irritation of the stomach and intestines, and lethargy leading to coma.
- Affected organisms
- Humans and other mammals
Pathway Category Metolazone Action Pathway Drug action
- Pharmacogenomic Effects/ADRs
- Not Available
- Drug Interactions
- This information should not be interpreted without the help of a healthcare provider. If you believe you are experiencing an interaction, contact a healthcare provider immediately. The absence of an interaction does not necessarily mean no interactions exist.
Drug Interaction Abacavir Metolazone may increase the excretion rate of Abacavir which could result in a lower serum level and potentially a reduction in efficacy. Acarbose The therapeutic efficacy of Acarbose can be decreased when used in combination with Metolazone. Acebutolol Metolazone may increase the hypotensive activities of Acebutolol. Aceclofenac The therapeutic efficacy of Metolazone can be decreased when used in combination with Aceclofenac. Acemetacin The therapeutic efficacy of Metolazone can be decreased when used in combination with Acemetacin. Acetaminophen Acetaminophen may increase the excretion rate of Metolazone which could result in a lower serum level and potentially a reduction in efficacy. Acetazolamide Acetazolamide may increase the excretion rate of Metolazone which could result in a lower serum level and potentially a reduction in efficacy. Acetohexamide The therapeutic efficacy of Acetohexamide can be decreased when used in combination with Metolazone. Acetyldigitoxin The risk or severity of adverse effects can be increased when Metolazone is combined with Acetyldigitoxin. Acetylsalicylic acid Acetylsalicylic acid may decrease the excretion rate of Metolazone which could result in a higher serum level.Additional Data Available
- Extended DescriptionExtended Description
Extended description of the mechanism of action and particular properties of each drug interaction.Learn more
A severity rating for each drug interaction, from minor to major.Learn more
- Evidence LevelEvidence Level
A rating for the strength of the evidence supporting each drug interaction.Learn more
An effect category for each drug interaction. Know how this interaction affects the subject drug.Learn more
- Food Interactions
- Take with food. Food reduces irritation.
- Product Images
- International/Other Brands
- Diulo / Diurem (Cipla) / Metadure (Micro Labs) / Metenix (IFET) / Metolaz (Navana) / Metoral (Dr. Reddy's) / Metoz (Centaur) / Metozone (Ying Yuan) / Mykrox (Celltech) / Pavedal (Pharma Investi) / Xuret / Zytanix (Zydus)
- Brand Name Prescription Products
Name Dosage Strength Route Labeller Marketing Start Marketing End Region Image Metolazone Tablet 5 mg/1 Oral H.j. Harkins Co., Inc. 2017-12-08 Not applicable Mykrox Tablets Tablet 500 ug/1 Oral UNSPECIFIED 2006-01-12 Not applicable Zaroxolyn Tablet 5 mg/1 Oral Physicians Total Care, Inc. 1973-11-27 2012-06-30 Zaroxolyn Tablet 5 mg/1 Oral Unither Pharmaceuticals 1973-11-27 2015-11-30 Zaroxolyn Tablet 5 mg Oral Aventis Pharma Ltd. 1974-12-31 2003-07-22 Zaroxolyn Tablet 2.5 mg/1 Oral Carilion Materials Management 1973-11-27 Not applicable Zaroxolyn Tablet 2.5 mg/1 Oral Physicians Total Care, Inc. 1973-11-27 2010-06-30 Zaroxolyn Tablet 2.5 mg Oral Sanofi Aventis 1974-12-31 Not applicable Zaroxolyn Tablet 2.5 mg/1 Oral Unither Pharmaceuticals 1973-11-27 2015-04-30 Zaroxolyn Tab 10mg Tablet Oral Rhone Poulenc Rorer 1974-12-31 1998-08-12
- Generic Prescription Products
Name Dosage Strength Route Labeller Marketing Start Marketing End Region Image Metolazone Tablet 5 mg/1 Oral Physicians Total Care, Inc. 2004-04-27 Not applicable Metolazone Tablet 5 mg/1 Oral Ncs Health Care Of Ky, Inc Dba Vangard Labs 2003-12-19 Not applicable Metolazone Tablet 5 mg/1 Oral Mylan Institutional Inc. 2005-02-01 Not applicable Metolazone Tablet 5 mg/1 Oral Amerincan Health Packaging 2010-10-04 2014-05-31 Metolazone Tablet 5 mg/1 Oral Lannett Company, Inc. 1973-11-27 Not applicable Metolazone Tablet 2.5 mg/1 Oral Mylan Pharmaceuticals Inc. 2004-01-06 Not applicable Metolazone Tablet 5 mg/1 Oral American Health Packaging 2020-05-01 Not applicable Metolazone Tablet 5 mg/1 Oral Carilion Materials Management 2004-10-19 Not applicable Metolazone Tablet 2.5 mg/1 Oral Ncs Health Care Of Ky, Inc Dba Vangard Labs 2010-01-18 Not applicable Metolazone Tablet 10 mg/1 Oral Eon Labs, Inc. 2003-12-19 Not applicable
- ATC Codes
- C03EA12 — Metolazone and potassium-sparing agents
- C03EA — Low-ceiling diuretics and potassium-sparing agents
- C03E — DIURETICS AND POTASSIUM-SPARING AGENTS IN COMBINATION
- C03 — DIURETICS
- C — CARDIOVASCULAR SYSTEM
- G01AE — Sulfonamides
- G01A — ANTIINFECTIVES AND ANTISEPTICS, EXCL. COMBINATIONS WITH CORTICOSTEROIDS
- G01 — GYNECOLOGICAL ANTIINFECTIVES AND ANTISEPTICS
- G — GENITO URINARY SYSTEM AND SEX HORMONES
- Drug Categories
- Antihypertensive Agents
- Antihypertensive Agents Indicated for Hypertension
- Cardiovascular Agents
- Drugs that are Mainly Renally Excreted
- Genito Urinary System and Sex Hormones
- Gynecological Antiinfectives and Antiseptics
- Heterocyclic Compounds, Fused-Ring
- Hyperglycemia-Associated Agents
- Hypotensive Agents
- Increased Diuresis
- Low-Ceiling Diuretics and Potassium-Sparing Agents
- Low-Ceiling Diuretics, Excl. Thiazides
- Membrane Transport Modulators
- Natriuretic Agents
- Non Potassium Sparing Diuretics
- Sodium Chloride Symporter Inhibitors
- Sulfur Compounds
- Thiazide-like Diuretic
- Chemical TaxonomyProvided by Classyfire
- This compound belongs to the class of organic compounds known as quinazolines. These are compounds containing a quinazoline moiety, which is made up of two fused six-member aromatic rings, a benzene ring and a pyrimidine ring.
- Organic compounds
- Super Class
- Organoheterocyclic compounds
- Sub Class
- Direct Parent
- Alternative Parents
- Toluenes / Secondary alkylarylamines / Organosulfonamides / Aryl chlorides / Vinylogous amides / Tertiary carboxylic acid amides / Aminosulfonyl compounds / Lactams / Amino acids and derivatives / Azacyclic compounds / Organopnictogen compounds / Organooxygen compounds / Organochlorides / Organic oxides / Hydrocarbon derivatives show 5 more
- Amine / Amino acid or derivatives / Aminosulfonyl compound / Aromatic heteropolycyclic compound / Aryl chloride / Aryl halide / Azacycle / Benzenoid / Carboxamide group / Carboxylic acid derivative / Hydrocarbon derivative / Lactam / Monocyclic benzene moiety / Organic nitrogen compound / Organic oxide / Organic oxygen compound / Organic sulfonic acid or derivatives / Organochloride / Organohalogen compound / Organonitrogen compound / Organooxygen compound / Organopnictogen compound / Organosulfonic acid amide / Organosulfonic acid or derivatives / Organosulfur compound / Quinazoline / Secondary aliphatic/aromatic amine / Secondary amine / Sulfonyl / Tertiary carboxylic acid amide / Toluene / Vinylogous amide show 22 more
- Molecular Framework
- Aromatic heteropolycyclic compounds
- External Descriptors
- sulfonamide, organochlorine compound, quinazolines (CHEBI:64354)
- CAS number
- InChI Key
- IUPAC Name
- General References
- Rosenberg J, Gustafsson F, Galatius S, Hildebrandt PR: Combination therapy with metolazone and loop diuretics in outpatients with refractory heart failure: an observational study and review of the literature. Cardiovasc Drugs Ther. 2005 Aug;19(4):301-6. [PubMed:16189620]
- Human Metabolome Database
- KEGG Drug
- PubChem Compound
- PubChem Substance
- Therapeutic Targets Database
- RxList Drug Page
- Drugs.com Drug Page
- PDRhealth Drug Page
- AHFS Codes
- 40:28.24 — Thiazide-like Diuretics
- FDA label
- Download (834 KB)
- Clinical Trials
Phase Status Purpose Conditions Count 4 Completed Treatment Heart Failure 1 4 Completed Treatment Rapid Ventricular Response Atrial Fibrillation 1 4 Suspended Prevention High Blood Pressure (Hypertension) / Novel Coronavirus Infectious Disease (COVID-19) 1 4 Terminated Treatment Acute Heart Failure (AHF) / Fluid Overload 1 4 Terminated Treatment Decompensated Heart Failure 1 4 Unknown Status Treatment Acute Heart Failure (AHF) / Cardiovascular Heart Disease / Heart Failure / Heart Failure With Reduced Ejection Fraction (HFrEF) 1 4 Unknown Status Treatment Congestive Heart Failure (CHF) 1 3 Recruiting Treatment Acute Heart Failure (AHF) 1 3 Terminated Treatment Decompensated Heart Failure 1 2 Not Yet Recruiting Other Chronic Kidney Disease (CKD) / End Stage Renal Disease (ESRD) 1
- Gd searle llc
- Mylan pharmaceuticals inc
- Roxane laboratories inc
- Sandoz inc
- Teva pharmaceuticals usa inc
- Watson laboratories inc
- Ucb inc
- Amerisource Health Services Corp.
- Cardinal Health
- Caremark LLC
- Diversified Healthcare Services Inc.
- Eon Labs
- Mckesson Corp.
- Murfreesboro Pharmaceutical Nursing Supply
- Pharmaceutical Utilization Management Program VA Inc.
- Physicians Total Care Inc.
- Prepackage Specialists
- Resource Optimization and Innovation LLC
- Sandhills Packaging Inc.
- Southwood Pharmaceuticals
- Teva Pharmaceutical Industries Ltd.
- UCB Pharma
- UDL Laboratories
- Upstate Pharma LLC
- Vangard Labs Inc.
- Dosage Forms
Form Route Strength Tablet Oral 10 mg/1 Tablet Oral 2.5 mg/1 Tablet Oral 5 mg/1 Tablet Oral 500 ug/1 Tablet Oral 10 MG Tablet Oral 2.5 mg Tablet Oral 5 MG Tablet Oral
Unit description Cost Unit Zaroxolyn 10 mg tablet 2.89USD tablet Zaroxolyn 5 mg tablet 2.75USD tablet Metolazone 10 mg tablet 1.8USD tablet Zaroxolyn 2.5 mg tablet 1.74USD tablet Metolazone 5 mg tablet 1.51USD tablet Metolazone 2.5 mg tablet 1.37USD tabletDrugBank does not sell nor buy drugs. Pricing information is supplied for informational purposes only.
- Not Available
- Experimental Properties
Property Value Source melting point (°C) 256 °C PhysProp water solubility 60.3 mg/L (at 25 °C) YALKOWSKY,SH & DANNENFELSER,RM (1992) logP 2.5 Not Available logS -3.78 ADME Research, USCD
- Predicted Properties
Property Value Source Water Solubility 0.0407 mg/mL ALOGPS logP 3.21 ALOGPS logP 2.94 ChemAxon logS -4 ALOGPS pKa (Strongest Acidic) 9.54 ChemAxon pKa (Strongest Basic) -1.6 ChemAxon Physiological Charge 0 ChemAxon Hydrogen Acceptor Count 4 ChemAxon Hydrogen Donor Count 2 ChemAxon Polar Surface Area 92.5 Å2 ChemAxon Rotatable Bond Count 2 ChemAxon Refractivity 94.59 m3·mol-1 ChemAxon Polarizability 36.38 Å3 ChemAxon Number of Rings 3 ChemAxon Bioavailability 1 ChemAxon Rule of Five Yes ChemAxon Ghose Filter Yes ChemAxon Veber's Rule No ChemAxon MDDR-like Rule No ChemAxon
- Predicted ADMET Features
Property Value Probability Human Intestinal Absorption + 0.9972 Blood Brain Barrier + 0.5944 Caco-2 permeable - 0.8957 P-glycoprotein substrate Non-substrate 0.7578 P-glycoprotein inhibitor I Non-inhibitor 0.8113 P-glycoprotein inhibitor II Non-inhibitor 0.5921 Renal organic cation transporter Non-inhibitor 0.9223 CYP450 2C9 substrate Non-substrate 0.6466 CYP450 2D6 substrate Non-substrate 0.8279 CYP450 3A4 substrate Non-substrate 0.579 CYP450 1A2 substrate Non-inhibitor 0.9045 CYP450 2C9 inhibitor Non-inhibitor 0.907 CYP450 2D6 inhibitor Non-inhibitor 0.923 CYP450 2C19 inhibitor Non-inhibitor 0.9025 CYP450 3A4 inhibitor Non-inhibitor 0.831 CYP450 inhibitory promiscuity Low CYP Inhibitory Promiscuity 0.5788 Ames test Non AMES toxic 0.8234 Carcinogenicity Non-carcinogens 0.7193 Biodegradation Not ready biodegradable 0.9961 Rat acute toxicity 1.8955 LD50, mol/kg Not applicable hERG inhibition (predictor I) Weak inhibitor 0.9922 hERG inhibition (predictor II) Non-inhibitor 0.8735
- Mass Spec (NIST)
- Not Available
Spectrum Spectrum Type Splash Key Predicted GC-MS Spectrum - GC-MS Predicted GC-MS Not Available Predicted MS/MS Spectrum - 10V, Positive (Annotated) Predicted LC-MS/MS Not Available Predicted MS/MS Spectrum - 20V, Positive (Annotated) Predicted LC-MS/MS Not Available Predicted MS/MS Spectrum - 40V, Positive (Annotated) Predicted LC-MS/MS Not Available Predicted MS/MS Spectrum - 10V, Negative (Annotated) Predicted LC-MS/MS Not Available Predicted MS/MS Spectrum - 20V, Negative (Annotated) Predicted LC-MS/MS Not Available Predicted MS/MS Spectrum - 40V, Negative (Annotated) Predicted LC-MS/MS Not Available LC-MS/MS Spectrum - LC-ESI-qTof , Positive LC-MS/MS Not Available LC-MS/MS Spectrum - LC-ESI-qTof , Positive LC-MS/MS Not Available MS/MS Spectrum - , positive LC-MS/MS splash10-0aor-1494000000-aae5f0a5c86e9d0828e2 MS/MS Spectrum - , positive LC-MS/MS splash10-0bvi-2960000000-1eed022b28a6bb140f60
- Pharmacological action
- General Function
- Transporter activity
- Specific Function
- Key mediator of sodium and chloride reabsorption in this nephron segment, accounting for a significant fraction of renal sodium reabsorption.
- Gene Name
- Uniprot ID
- Uniprot Name
- Solute carrier family 12 member 3
- Molecular Weight
- 113138.04 Da
- Chen X, Ji ZL, Chen YZ: TTD: Therapeutic Target Database. Nucleic Acids Res. 2002 Jan 1;30(1):412-5. [PubMed:11752352]
Drug created on June 13, 2005 07:24 / Updated on October 27, 2020 11:13