Midodrine
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Sympathomimetics and Sympatholytics (Old)
- Dopamine
- Fenoldopam
- Dobutamine
- Epinephrine
- Norepinephrine
- Isoproterenol
- Midodrine
- Phenylephrine and Pseudoephedrine
- (Alpha) Methyldopa
- Clonidine (and Guanfacine)
- Tizanidine
Summary
Midodrine is a selective activator or agonist of alpha-1 adrenergic receptors. Alpha-1 activity then induces systemic vasoconstriction, which is useful in the treatment of orthostatic hypotension.
Key Points
- Midodrine
- Mechanism of Action
- Alpha-1 Agonist
- Arterial Vasoconstriction → Increased TPR
- Venous Vasoconstriction → Increased Venous Return → Increased Cardiac Output
- Alpha-1 Agonist
- Clinical Use
- Autonomic Insufficiency
- Orthostatic Hypotension
- Alpha 1-mediated venous vasoconstriction helps maintain venous return despite the effects of gravity from standing up
- Adverse Effects
- May exacerbate supine hypertension (can be extrapolated from its clinical use)
- Mechanism of Action