Home Drug Guide Methyldopa

Drug Guide

Generic Name

Methyldopa

Brand Names Aldomet

Classification

Therapeutic: Antihypertensive

Pharmacological: Central alpha-2 adrenergic agonist

FDA Approved Indications

  • Management of hypertension, especially in pregnant women

Mechanism of Action

Methyldopa is converted in the central nervous system to alpha-methyl norepinephrine, which stimulates central alpha-2 adrenergic receptors, reducing sympathetic outflow and thereby decreasing blood pressure.

Dosage and Administration

Adult: Initial dose: 250 mg 2-3 times daily; titrate gradually up to a total of 1,000 mg/day in divided doses as needed and tolerated.

Pediatric: Dosage varies depending on weight and clinical response; consult pediatric dosing guidelines.

Geriatric: Start at lower doses; monitor closely due to increased susceptibility to hypotension and CNS effects.

Renal Impairment: Adjust dose based on renal function; closely monitor blood pressure.

Hepatic Impairment: Use with caution; no specific dose adjustment established.

Pharmacokinetics

Absorption: Well absorbed orally.

Distribution: Widely distributed, crosses the blood-brain barrier.

Metabolism: Partially metabolized in the liver.

Excretion: Excreted primarily in the urine, both as unchanged drug and metabolites.

Half Life: Approximately 2-3 hours.

Contraindications

  • Hypersensitivity to methyldopa or its components.
  • History of hepatic disease or existing abnormal liver function.

Precautions

  • Use with caution in patients with renal impairment, cerebrovascular disease, or history of depression. Monitor liver function regularly.
  • Pregnancy category B; generally considered safe in pregnancy but monitor hepatic function.

Adverse Reactions - Common

  • Sedation, fatigue (Common)
  • Dizziness, orthostatic hypotension (Common)
  • Dry mouth, nasal congestion (Common)

Adverse Reactions - Serious

  • Hepatotoxicity, including hepatitis and liver failure (Rare)
  • Hemolytic anemia (Rare)
  • Positive Coombs test (Rare)
  • Fluid retention, lupus erythematosus-like syndrome (Rare)

Drug-Drug Interactions

  • MAO inhibitors (risk of hypertensive crisis), other antihypertensives (additive effect)
  • Certain antidepressants

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor blood pressure regularly; assess for signs of liver dysfunction (jaundice, dark urine); assess mental status.

Diagnoses:

  • Risk for hypotension
  • Impaired liver function

Implementation: Administer doses with food to reduce gastrointestinal upset; titrate dose carefully; monitor blood pressure and liver function tests periodically.

Evaluation: Assess for effectiveness in blood pressure control; monitor for adverse effects, especially hepatotoxicity.

Patient/Family Teaching

  • Take medication exactly as prescribed.
  • Report symptoms of liver problems (jaundice, dark urine), mental changes, or signs of allergic reactions.
  • Avoid abrupt discontinuation to prevent hypertensive crisis.
  • Monitor blood pressure regularly at home.

Special Considerations

Black Box Warnings:

  • Hepatotoxicity; discontinue if signs of liver dysfunction occur.

Genetic Factors: None established.

Lab Test Interference: Can cause a positive Coombs test, which may indicate hemolytic anemia.

Overdose Management

Signs/Symptoms: Hypotension, bradycardia, sedation, respiratory depression in severe cases.

Treatment: Supportive care, discontinue drug, monitor vital signs, and provide symptomatic treatment.

Storage and Handling

Storage: Store in a tightly closed container at room temperature, away from heat and moisture.

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.