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Clonidine (Sympatholytic)
[klo ni' deen]
  • Clonidine acts in the brain, inhibiting adrenergic outflow from the brainstem. Inhibition of sympathetic outflow results in a decrease in blood pressure.

  • Clonidine reduces cardiac output:

    • (by reducing both stroke volume and heart rate) and peripheral resistance.

    • Reduction in stoke volume occurs due to increased venous pooling (decreased preload).

  • Clonidine does not interfere with cardiovascular responses to exercise.

  • Renal blood flow and function is maintained during clonidine treatment.

  • Clonidine has minimal or no effect on plasma lipids.

  • Adverse Effects:

    • Dry Mouth (xerostomia)

    • Bradycardia (in patients with SA nodal abnormality)

    • Withdrawal syndrome upon abrupt discontinuation (increased blood pressure, headache, tachycardia, apprehension, tremors)