Nurses Compass
Drug Guide
Methyclothiazide
Classification
Therapeutic: Antihypertensive, Diuretic
Pharmacological: Thiazide diuretic
FDA Approved Indications
- Hypertension (high blood pressure)
- Fluid retention (edema)
Mechanism of Action
Methyclothiazide inhibits sodium reabsorption in the distal tubules of the kidney, leading to increased excretion of sodium, chloride, and water, which decreases blood volume and blood pressure.
Dosage and Administration
Adult: Typically 25 mg once daily, dosage may be adjusted based on response.
Pediatric: Use is not well-established; consult specific guidelines.
Geriatric: Start with lower doses due to potential increased sensitivity; monitor closely.
Renal Impairment: Use with caution; dose adjustments may be necessary.
Hepatic Impairment: Use with caution; no specific adjustments well-established.
Pharmacokinetics
Absorption: Absorbed from GI tract, bioavailability approximately 80%.
Distribution: Widely distributed; cross-reactivity with other sulfonamide drugs may occur.
Metabolism: Minimal hepatic metabolism.
Excretion: Primarily excreted unchanged in urine.
Half Life: Approximately 4-6 hours; may be prolonged in renal impairment.
Contraindications
- Hypersensitivity to sulfonamides or thiazide diuretics.
- Anuria (absence of urine production).
Precautions
- Electrolyte disturbances (hypokalemia, hyponatremia), gout, diabetes mellitus, hepatic impairment, pregnancy/lactation, gout.
Adverse Reactions - Common
- Electrolyte imbalances (hypokalemia, hyponatremia) (Common)
- Dizziness, weakness (Common)
- Gastrointestinal disturbances (Common)
Adverse Reactions - Serious
- Stevens-Johnson syndrome, toxic epidermal necrolysis (Rare)
- Electrolyte disturbances leading to cardiac dysrhythmias (Rare)
- Hypersensitivity reactions (Rare)
Drug-Drug Interactions
- Lithium (risk of toxicity), other antihypertensives (additive effect), corticosteroids (potassium loss)
Drug-Food Interactions
- High salt intake may reduce efficacy.
Drug-Herb Interactions
N/ANursing Implications
Assessment: Monitor blood pressure, electrolyte levels, renal function, hydration status.
Diagnoses:
- Risk for electrolyte imbalance, risk for hypotension.
Implementation: Administer in the morning to prevent nocturia; monitor BP and electrolytes regularly.
Evaluation: Assess blood pressure response and electrolyte levels to gauge effectiveness and safety.
Patient/Family Teaching
- Take medication exactly as prescribed.
- Report muscle weakness, dizziness, or palpitations.
- Maintain adequate hydration.
- Limit high salt intake if recommended.
Special Considerations
Black Box Warnings: N/A
Genetic Factors: N/A
Lab Test Interference: May affect glucose and electrolyte testing.
Overdose Management
Signs/Symptoms: Severe electrolyte imbalances, dehydration, hypotension.
Treatment: Discontinue medication, correct electrolyte imbalances, provide supportive care, initiate IV fluids if necessary.
Storage and Handling
Storage: Store at room temperature away from light and moisture.
Stability: Stable for 2-3 years under proper conditions.