Home Drug Guide Chlorothiazide

Drug Guide

Generic Name

Chlorothiazide

Brand Names Diuril

Classification

Therapeutic: Antihypertensive; Diuretic

Pharmacological: Thiazide diuretic

FDA Approved Indications

  • Hypertension
  • Edema associated with congestive heart failure, cirrhosis of the liver, and corticosteroid and estrogen therapy

Mechanism of Action

Inhibits sodium reabsorption in the distal tubules of the kidney, leading to increased excretion of sodium, chloride, and water, thereby reducing blood volume and lowering blood pressure.

Dosage and Administration

Adult: Initial dose: 500 mg once daily or in two divided doses. Dose may be increased as needed, typically up to 2 g per day.

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

Geriatric: Start at lower doses due to increased risk of hypotension and electrolyte imbalance; monitor closely.

Renal Impairment: Use with caution; may require dose adjustments and frequent monitoring.

Hepatic Impairment: Use with caution; avoid in severe impairment due to limited data.

Pharmacokinetics

Absorption: Well absorbed orally.

Distribution: Widely distributed, including into the cerebrospinal fluid; highly protein-bound.

Metabolism: Primarily unchanged in the urine; minimal hepatic metabolism.

Excretion: Renal excretion, mainly unchanged.

Half Life: Approximate plasma half-life of 7-14 hours.

Contraindications

  • Hypersensitivity to chlorothiazide or other sulfonamide-derived drugs
  • Anuria

Precautions

  • Electrolyte disturbances (hypokalemia, hyponatremia), gout, lupus erythematosus, diabetes mellitus, renal or hepatic impairment, elderly patients

Adverse Reactions - Common

  • Electrolyte disturbances (hypokalemia, hyponatremia) (Common)
  • Increased urination (Common)
  • Hyperuricemia (Common)

Adverse Reactions - Serious

  • Electrolyte imbalance leading to arrhythmias, hypotension, dehydration (Serious)
  • Stevens-Johnson syndrome, toxic epidermal necrolysis (Rare)

Drug-Drug Interactions

  • Digoxin (risk of hypokalemia increasing toxicity), corticosteroids (additive hypokalemia), other antihypertensives

Drug-Food Interactions

  • Alcohol (may enhance hypotensive effect)

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor blood pressure, serum electrolytes, renal function, hydration status.

Diagnoses:

  • Deficient fluid volume r/t excessive diuresis
  • Electrolyte imbalance, risk of hypokalemia

Implementation: Administer with meals to minimize gastrointestinal upset; monitor electrolyte levels regularly.

Evaluation: Assess blood pressure response, electrolyte levels, and signs of dehydration or electrolyte imbalance.

Patient/Family Teaching

  • Take medication exactly as prescribed.
  • Report symptoms of electrolyte imbalance (muscle weakness, cramps, irregular heartbeat).
  • Limit alcohol intake, and avoid excessive salt or potassium supplements unless directed.
  • Follow up for blood tests to monitor electrolytes and renal function.

Special Considerations

Black Box Warnings:

  • Electrolyte imbalances can lead to serious cardiac arrhythmias.

Genetic Factors: None specifically documented.

Lab Test Interference: May cause false elevation of serum uric acid or glucose levels.

Overdose Management

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

Treatment: Discontinue drug, correct electrolyte imbalances with IV fluids and electrolytes, monitor vital signs and renal function.

Storage and Handling

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

Stability: Stable under recommended storage conditions.

🛡️ 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.