Direct Vasodilators

Overview

• Direct vasodilators cause dilation of blood vessels.
• Not widely used due to availability of better options.

Mechanism of Action

• Direct Arterial Smooth Muscle Relaxation
  • Causes dilation of vessels.
  • Improves transport of O2, nutrients, and glucose.
  • Regulates and decreases blood pressure.

Therapeutic Effects

• Decrease blood pressure.
• Decrease constriction and peripheral vascular resistance.
• Decrease afterload.

Indications

• Treatment for hypertension.
• Malignant hypertension (uncontrolled, rapid, and extreme high blood pressure).

Precautions

• Careful with concurrent use of multiple BP-affecting drugs due to increased hypotensive effects.
• Typically administered IV (intravenously).
• Caution with renal disease and stroke due to risk of severe hypotension.

Contraindications

• Patients with cerebral edema as it can increase intracranial pressure.
• Acute myocardial infarction (MI).

Adverse Effects

• Headache and dizziness.
• Possible tachycardia (increased heart rate).

Nursing Implications

• Monitor heart rate and blood pressure.

Patient Education

• Educate on drug side effects and BP monitoring.
• Understand symptoms of hypotension.
• Be aware of interactions with other drugs.

Example Drug

• Hydralazine

Summary

• Direct vasodilators cause arterial smooth muscle relaxation leading to vessel dilation and decreased blood pressure.