Nurses Compass
Drug Guide
Methyldopate Hydrochloride
Classification
Therapeutic: Antihypertensive
Pharmacological: Alpha-2 adrenergic agonist
FDA Approved Indications
- Hypertension
Mechanism of Action
Methyldopate is converted in the central nervous system to methylnorepinephrine, which stimulates alpha-2 adrenergic receptors, reducing sympathetic outflow and decreasing blood pressure.
Dosage and Administration
Adult: Initially 250 mg 2-3 times daily, titrated up as needed; usual maintenance dose 250-500 mg 2-3 times daily.
Pediatric: Not commonly used in children; dosage should be individualized under medical supervision.
Geriatric: Start at lower end of dosing range due to increased sensitivity and risk of hypotension.
Renal Impairment: Use with caution; monitor blood pressure closely and adjust dose accordingly.
Hepatic Impairment: No specific adjustment supported; cautious use recommended.
Pharmacokinetics
Absorption: Rapidly absorbed from the gastrointestinal tract.
Distribution: Widely distributed throughout the body.
Metabolism: Metabolized in the central nervous system to active metabolites.
Excretion: Excreted primarily in the urine.
Half Life: Approximately 2-3 hours.
Contraindications
- Hypersensitivity to methyldopate or other components.
- History of depression or active depression.
Precautions
- Use with caution in patients with hepatic disease, psychiatric conditions, or in those requiring psychiatric stability.
- Pregnancy: Generally considered safe, but should be used under medical supervision, especially during the first trimester. Breastfeeding: Use with caution; consult healthcare provider.
Adverse Reactions - Common
- Drowsiness, sedation (Common)
- Dry mouth (Common)
- Dizziness (Common)
Adverse Reactions - Serious
- Hemolytic anemia (Serious but rare)
- Liver dysfunction or hepatitis (Rare)
- Hypotension or orthostatic hypotension (Variable)
Drug-Drug Interactions
- MAO inhibitors may enhance hypotensive effects.
- Other antihypertensives may increase blood pressure lowering.
Drug-Food Interactions
N/ADrug-Herb Interactions
N/ANursing Implications
Assessment: Monitor blood pressure regularly, assess for signs of depression, liver function tests as indicated.
Diagnoses:
- Ineffective tissue perfusion related to hypotension.
- Risk for injury related to orthostatic hypotension.
Implementation: Administer orally as prescribed; advise patient to rise slowly from sitting or lying position.
Evaluation: Assess blood pressure response, monitor for adverse effects, and adjust dose as needed.
Patient/Family Teaching
- Take medication exactly as prescribed.
- Warn about possible drowsiness and advise against driving or operating machinery until response is known.
- Report symptoms of depression, jaundice, or unusual bleeding.
Special Considerations
Black Box Warnings: N/A
Genetic Factors: N/A
Lab Test Interference: May interfere with certain laboratory tests of hepatic function.
Overdose Management
Signs/Symptoms: Severe hypotension, sedation, depression.
Treatment: Maintain airway, monitor blood pressure, administer IV fluids, and use vasopressors if needed; gastric lavage or activated charcoal may be considered if ingestion was recent.
Storage and Handling
Storage: Store at room temperature, away from moisture and light.
Stability: Stable under usual storage conditions for prescribed shelf life.