Home Drug Guide Prazosin Hydrochloride

Drug Guide

Generic Name

Prazosin Hydrochloride

Brand Names Minipress, Minipress XL

Classification

Therapeutic: Antihypertensive, Alpha-1 Adrenergic Blocker

Pharmacological: Alpha-1 Adrenergic Antagonist

FDA Approved Indications

  • Hypertension
  • Benign Prostatic Hyperplasia (BPH)

Mechanism of Action

Prazosin selectively blocks alpha-1 adrenergic receptors in vascular smooth muscle, resulting in vasodilation and decreased blood pressure. It also relaxes smooth muscle in the prostate and bladder neck, improving urinary flow in BPH.

Dosage and Administration

Adult: Starting dose is typically 1 mg two or three times daily, titrated up as needed to control blood pressure, not exceeding 20 mg per day.

Pediatric: Not typically used in pediatric patients.

Geriatric: Start at lower doses due to increased sensitivity; titrate carefully.

Renal Impairment: Use caution; dosage adjustment may be necessary depending on severity.

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

Pharmacokinetics

Absorption: Well absorbed orally.

Distribution: Significantly bound to plasma proteins.

Metabolism: Partially metabolized in the liver.

Excretion: Excreted mainly in the urine.

Half Life: 2 to 3 hours.

Contraindications

  • Hypersensitivity to prazosin or other quinazoline derivatives.

Precautions

  • Caution in patients with a history of syncope, hepatic impairment, or orthostatic hypotension.

Adverse Reactions - Common

  • Dizziness (Common)
  • Drowsiness (Less common)
  • Headache (Less common)
  • NV (nausea and vomiting) (Less common)

Adverse Reactions - Serious

  • Syncope (fainting) (Less common)
  • Priapism (Rare)
  • Dyspnea (Rare)
  • Laryngeal edema (Rare)

Drug-Drug Interactions

  • Other antihypertensives (additive hypotension)
  • Phosphodiesterase inhibitors (risk of hypotension)

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor blood pressure regularly, especially during dose titration and for orthostatic hypotension.

Diagnoses:

  • Risk for Falls related to hypotension and dizziness.
  • Ineffective tissue perfusion related to vasodilation.

Implementation: Administer initially at bedtime to decrease episodic dizziness. Titrate dose gradually. Educate patient to rise slowly from sitting or lying position.

Evaluation: Evaluate blood pressure response, symptom improvement, and adverse effects.

Patient/Family Teaching

  • Take medication exactly as prescribed.
  • Rise slowly from seated or lying positions to avoid dizziness and falls.
  • Notify healthcare provider if experiencing dizziness, fainting, or other concerning symptoms.
  • Avoid sudden changes in position.

Special Considerations

Black Box Warnings:

  • None currently

Genetic Factors: None established.

Lab Test Interference: May cause false-positive results in certain lab tests for catecholamines.

Overdose Management

Signs/Symptoms: Severe hypotension, dizziness, tachycardia or bradycardia, syncope.

Treatment: Place patient in supine position, monitor vital signs, administer IV fluids as needed, use vasopressors if necessary; activated charcoal if ingestion is recent.

Storage and Handling

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

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.