Metolazone


Concise Prescribing Info
Indications/Uses
Listed in Dosage.
Dosage/Direction for Use
Adult : PO HTN Initial:1.25 mg/day, adjusted after 3-4 wk. Usual range: 2.5-5 mg/day, either alone or w/ other antihypertensives. Maintenance: 5 mg on alternate days. Oedema 5-10 mg/day, up to 20 mg/day if needed. Max: 80 mg/24 hr.
Dosage Details
Oral
Hypertension
Adult: Initially, 1.25 mg daily, adjusted after 3-4 wk according to response. Usual dose: 2.5-5 mg daily, either alone or with other antihypertensives. Maintenance dose: 5 mg on alternate days. Formulations with enhanced bioavailability: 0.5-1 mg daily.
Elderly: Initially, 2.5 mg/day or every other day.

Oral
Oedema
Adult: 5-10 mg daily, increased if necessary to 20 mg daily. Max: 80 mg in 24 hr.
Elderly: Initially, 2.5 mg/day or every other day.
Administration
Should be taken with food. Take after breakfast.
Contraindications
Anuria; hepatic coma or pre-coma. Pregnancy.
Special Precautions
Pre-diabetes or DM; gout; SLE; hepatic and renal impairment; hypercholesterolaemia. Correct electrolyte disturbances prior to therapy. Risk of cross-sensitivity with sulfonamides, sulfonylureas, carbonic anhydrase inhibitors, thiazides and loop diuretics. Lactation.
Adverse Reactions
Chest pain, palpitation, necrotising angiitis, orthostatic hypotension, syncope, venous thrombosis, vertigo, volume depletion; depression, dizziness, chills, drowsiness, fatigue, restlessness, headache, lightheadedness; petechiae, photosensitivity, hypersensitivity reactions; gout attacks, electrolyte disturbances; abdominal bloating, diarrhoea, abdominal pain, anorexia, constipation, epigastric distress, nausea, xerostomia, pancreatitis, vomiting; impotence; aplastic anaemia, thrombocytopenia, haemoconcentration, leukopenia; cholestatic jaundice, hepatitis; joint pain, muscle cramps, weakness, neuropathy, paraesthesia; blurred vision; increased BUN, glucosuria.
Potentially Fatal: Stevens-Johnson syndrome, toxic epidermal necrolysis.
Overdosage
Symptoms: Orthostatic hypotension, dizziness, drowsiness, syncope, haemoconcentration and haemodynamic changes due to plasma volume depletion. Management: Symptomatic and supportive.
Drug Interactions
Hypotensive and nephrotoxic effects of ACE inhibitors may be enhanced. Absorption may be reduced with bile acid sequestrants. Hyperglycaemic effect may be enhanced with diazoxide. May increase serum concentration and QTc-prolonging effect of dofetilide. May reduce lithium excretion. Hypotensive effect may be increased with alcohol.
Potentially Fatal: Increased risk of nephrotoxicity with ciclosporin. Severe electrolyte disturbances may occur with furosemide.
Food Interaction
Photosensitisation may occur with dong quai, St John's wort. Hypertension may be exacerbated with ephedra, yohimbe, ginseng. Antihypertensive effect may be increased with garlic. Avoid natural licorice.
Action
Description: Metolazone is a thiazide-like diuretic. It inhibits reabsorption of sodium in the distal tubules resulting in increased excretion of sodium and water, as well as potassium and hydrogen ions.
Onset: Approx 60 min.
Duration: ≤24 hr.
Pharmacokinetics:
Absorption: Incompletely absorbed from the GI tract (oral).
Distribution: Crosses the placenta and enters breast milk. Protein-binding: 95%.
Metabolism: Not metabolised to a substantial extent.
Excretion: Via urine (80-95% unchanged); via bile and some undergo enterohepatic recycling; 6-20 hr (elimination half-life).
MIMS Class
Disclaimer: This information is independently developed by MIMS based on Metolazone from various references and is provided for your reference only. Therapeutic uses, prescribing information and product availability may vary between countries. Please refer to MIMS Product Monographs for specific and locally approved prescribing information. Although great effort has been made to ensure content accuracy, MIMS shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2020 MIMS. All rights reserved. Powered by MIMS.com
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