Home Drug Guide Metolazone

Drug Guide

Generic Name

Metolazone

Brand Names Zaroxolyn, Diulo, Mykrox

Classification

Therapeutic: Diuretic, Antihypertensive

Pharmacological: Thiazide-like diuretic

FDA Approved Indications

  • Edema associated with congestive heart failure, hepatic cirrhosis, or renal disease
  • Hypertension

Mechanism of Action

Metolazone inhibits sodium reabsorption primarily in the distal convoluted tubule of the nephron, leading to increased excretion of sodium, chloride, and water, thereby reducing blood volume and blood pressure.

Dosage and Administration

Adult: Initially, 5 mg once daily. Dose may be increased to 10–20 mg daily based on response.

Pediatric: Not generally recommended for children due to lack of sufficient data.

Geriatric: Start at lower doses due to increased sensitivity; monitor renal function and electrolytes closely.

Renal Impairment: Adjust dose based on renal function; efficacy may be diminished in severe impairment.

Hepatic Impairment: Use with caution; no specific dosing adjustments established.

Pharmacokinetics

Absorption: Well absorbed orally.

Distribution: Widely distributed; volume of distribution not well established.

Metabolism: Minimal hepatic metabolism.

Excretion: Primarily renal excretion.

Half Life: Approximately 24 hours.

Contraindications

  • Allergy to sulfonamides or thiazides.
  • Anuria.
  • Electrolyte imbalances such as hyponatremia, hypokalemia.

Precautions

  • Monitor renal function, electrolytes, and blood pressure regularly.
  • Use with caution in patients with gout, systemic lupus erythematosus, or diabetes.

Adverse Reactions - Common

  • Electrolyte disturbances (hyponatremia, hypokalemia) (Common)
  • Dehydration (Common)
  • Dizziness or lightheadedness (Common)

Adverse Reactions - Serious

  • Electrolyte imbalance leading to arrhythmias (Serious)
  • Hypersensitivity reactions (Rare)
  • Blood dyscrasias (Rare)

Drug-Drug Interactions

  • Other antihypertensives, NSAIDs, lithium, digitalis, corticosteroids

Drug-Food Interactions

  • Alcohol may enhance hypotensive effects

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor blood pressure, serum electrolytes, renal function, and for signs of dehydration.

Diagnoses:

  • Risk for electrolyte imbalance
  • Ineffective tissue perfusion related to hypotension

Implementation: Administer in the morning to reduce sleep disturbances; ensure adequate fluid and electrolyte intake.

Evaluation: Assess blood pressure and electrolytes regularly; evaluate for signs of dehydration or electrolyte imbalance.

Patient/Family Teaching

  • Take medication exactly as prescribed.
  • Report signs of electrolyte imbalance like muscle weakness, cramps, irregular heartbeat.
  • Avoid excessive salt substitutes containing potassium unless prescribed.
  • Follow-up blood tests to monitor electrolytes and renal function.

Special Considerations

Black Box Warnings:

  • Electrolyte disturbances may lead to arrhythmias.
  • Use with caution in patients with gout as it may precipitate attacks.

Genetic Factors: No specific genetic testing required.

Lab Test Interference: May alter serum electrolytes, blood glucose, or uric acid levels.

Overdose Management

Signs/Symptoms: Severe electrolyte imbalance, dehydration, hypotension.

Treatment: Discontinue medication, provide supportive care, correct electrolyte imbalances, and maintain hydration.

Storage and Handling

Storage: Store at room temperature, away from moisture and light.

Stability: Stable when stored properly.

🛡️ 5 Critical Medication Safety Tips for Nurses

1

Triple-Check High-Risk Medications

Always have another nurse verify insulin, heparin, warfarin, and chemotherapy drugs. These "high-alert" medications cause the most serious errors. Check concentration, dose calculation, and pump settings twice.

2

Know Look-Alike, Sound-Alike Drugs

Common mix-ups: hydromorphone/morphine, Celebrex/Celexa, Zyprexa/Zyrtec. Always use BOTH generic and brand names, read labels twice, and use barcode scanning when available. One wrong letter can be fatal.

3

Assess Before AND After Giving Meds

Check vitals before cardiac meds, pain levels before analgesics, and blood glucose before insulin. Always reassess within 30 minutes to evaluate effectiveness and watch for adverse reactions.

4

Watch for Drug Interactions

Common dangerous combinations: warfarin + aspirin (bleeding), ACE inhibitors + potassium (hyperkalemia), digoxin + diuretics (toxicity). Always check drug interactions before administering new medications.

5

Educate Your Patients

Teach patients medication names, purposes, major side effects, and what to report. Informed patients catch errors and improve compliance. Always encourage questions - an educated patient is a safer patient.

⚡ Remember: When in doubt, don't give it out! It's always safer to double-check than regret later.

⚠️ Medical Disclaimer

This drug guide is for educational purposes only and is NOT intended for clinical use. Always consult current prescribing information, healthcare providers, and institutional protocols before administering any medication. Do not use this information for patient care decisions.