Names and pronunciation
(me-tole′a-zone) Zaroxolyn
Source page 876
Loading InternPractice…
Individual generic drug information
Extracted information for metolazone only.
(me-tole′a-zone) Zaroxolyn
Source page 876
Func. class.: Diuretic, antihypertensive
Source page 876
Chem. class.: Thiazide-like quinazoline derivative
Source page 876
Do not confuse: metolazone/methotrexate/methadone/ metoclopramide
Source page 877
ACTION: Acts on distal tubule by increasing excretion of water, sodium, chloride, potassium, magnesium, bicar- bonate; decreases GFR
Source page 877
USES: Edema, hypertension, heart fail- ure, nephrotic syndrome
Source page 877
Extracted information for metolazone only.
CONTRAINDICATIONS: Hyper- sensitivity to thiazides, sulfonamides; anuria, hepatic coma, hepatic encephalopathy Precautions: Pregnancy, breastfeeding, geriatric patients, hypokalemia, renal/ hepatic disease, gout, COPD, lupus erythe- matosus, diabetes mellitus, hypotension, his- tory of pancreatitis; electrolyte imbalance
Source page 877
SIDE EFFECTS CNS: Drowsiness, lethargy CV: Orthostatic hypotension, palpita- tions, hypotension, chest pain, volume depletion ELECT: Hypokalemia, hypercalcemia, hyponatremia, hyperuricemia, hypomag- nesemia, hypophosphatemia, hypovolemia GI: Nausea, vomiting, anorexia, consti- pation, diarrhea, cramps, pancreatitis, GI irritation, dry mouth, jaundice, hepatitis GU: Urinary frequency, polyuria, ure- mia, glucosuria, nocturia, impotence, hyperuricemia HEMA: Aplastic anemia, hemolytic anemia, leukopenia, agranulocytosis, neutropenia EENT: Blurred vision INTEG: Rash, urticaria, purpura, photo- sensitivity, fever, dry skin, toxic epidermal necrolysis, Stevens-Johnson syndrome ENDO: Hyperglycemia, increased creati- nine, BUN MS: Muscle cramps, joint pain, swelling
Source page 877
INTERACTIONS Increase: hyperglycemia—antidiabetics Increase: hypokalemia—mezlocillin, piperacillin, amphotericin B, glucocorti- M coids, digoxin, stimulant laxatives Increase: hypotension—alcohol (large amounts), nitrates, antihypertensives, barbiturates, opioids Increase: toxicity—lithium Increase: metOLazone effects—loop diuretics Decrease: action of metOLazone, increase renal failure risk—NSAIDs, salicylates Drug/Food Increase: severe hypokalemia—licorice Drug/Herb Decrease: antihypertensive effect— ephedra (ma huang) Increase: antihypertensive effect— hawthorn Drug/Lab Test Increase: calcium, cholesterol, glucose, triglycerides Decrease: potassium, sodium, chloride, magnesium, WBC, Hb Interference: parathyroid function tests
Source page 877
TREATMENT OF OVERDOSE: Lavage if taken orally; monitor electrolytes; administer dextrose in saline; monitor hydration, CV, renal status HIGH ALERT
Source page 878
Extracted information for metolazone only.
DOSAGE AND ROUTES Edema in heart failure/renal disease • Adult: PO 5-20 mg/day; max 20 mg/ day Hypertension • Adult: PO 2.5-5 mg/day • Child: PO 0.2-0.4 mg/kg/day in di- vided doses q12-24hr
Source page 877
Available forms: Tabs 2.5, 5, 10 mg
Source page 877
Administer: • In AM to avoid interference with sleep if using product as diuretic • Potassium replacement if potassium <3 mg/dL • With food if nausea occurs; absorption may be decreased slightly
Source page 877
Extracted information for metolazone only.
Assess: • Weight, I&O daily to determine fluid loss; effect of product may be decreased if used daily • HF: improvement in edema of feet, legs, sacral area daily if product being used • Hypertension: B/P lying, standing; pos- tural hypotension may occur • Electrolytes: potassium, magnesium, sodium, chloride; include BUN, blood glucose, CBC, serum creatinine, blood pH, ABGs, uric acid, calcium • Hypokalemia: postural hypotension, malaise, fatigue, tachycardia, leg cramps, weakness • Rashes, temperature daily • Confusion, especially among geriatric patients; take safety precautions if needed • Hepatic encephalopathy: do not use in hepatic coma or precoma; fluctuations in electrolytes can occur rapidly and pre- cipitate hepatic coma; use caution in pa- tients with impaired hepatic function • Pregnancy/breastfeeding: use in pregnancy only if needed, no well-con- trolled studies; do not breastfeed, ap- pears in breast milk • Beers: use with older adults may exac- erbate or cause SIADH; monitor sodium level frequently
Source pages 877, 878
Evaluate: • Therapeutic response: decreased edema, B/P
Source page 878
CLINICAL CONSIDERATIONS
Source page 877
Patient and caregiver information: • To rise slowly from lying or sitting position • To notify prescriber of muscle weak- ness, cramps, nausea, dizziness • That product may be taken with food or milk • To use sunscreen, protective clothing for photosensitivity • That blood glucose may be increased in diabetics • To take early in day to avoid nocturia, to take at same time of day, not to skip or double doses, that skipped dose should be taken when remembered if not close to next dose • To avoid alcohol • To avoid sodium foods; to increase potassium foods in diet • Not to stop product abruptly
Source page 878
Extracted information for metolazone only.
PHARMACOKINETICS Protein binding 33%, peak 8 hr, duration 12-24 hr, excreted unchanged by kid- neys, crosses placenta, enters breast milk, half-life 14 hr
Source page 877
Filter the extracted dose blocks for this individual drug.
Edema in heart failure/renal disease
• Adult: PO 5-20 mg/day; max 20 mg/ day Hypertension
Candidate age grouping · source page 877
Edema in heart failure/renal disease
• Adult: PO 2.5-5 mg/day
Candidate age grouping · source page 877
Edema in heart failure/renal disease
• Child: PO 0.2-0.4 mg/kg/day in di- vided doses q12-24hr
Candidate age grouping · source page 877