Midodrine
Indications
Midodrine is used for:
Orthostatic hypotension
Adult Dose
Oral
Orthostatic hypotension
Adult: Initially, 2.5 mg 2-3 times daily, adjusted gradually according to response at weekly intervals, up to 10 mg tid. Last dose of the day should not be taken after evening meal or <4 hr before bedtime to reduce potential for supine HTN.
Renal impairment: Initially, 2.5 mg 2-3 times daily, gradually increased as tolerated.
Child Dose
Renal Dose
Administration
Contra Indications
Severe organic heart disease (e.g. bradycardia, ischaemic heart disease, CHF), acute renal failure, urinary retention, phaeochromocytoma, thyrotoxicosis, persistent and excessive supine HTN.
Precautions
Patient w/ DM, history of visual problems (esp when taken w/ fludrocortisone). Hepatic and renal impairment. Pregnancy and lactation. Monitoring Parameters Monitor supine and sitting BP; hepatic and renal function.
Pregnancy-Lactation
Pregnancy category: C
Lactation: Not known if excreted into breast milk; avoid
Interactions
Enhanced pressor effects w/ α-adrenergic agonists (e.g. phenylephrine, ephedrine, dihydroergotamine, phenylpropanolamine, pseudoephedrine). Reduced effect w/ α-adrenergic blockers (e.g. prazosin, terazosin, doxazosin). May precipitate bradycardia, AV block, or arrhythmia w/ cardiac glycosides.
Adverse Effects
Side effects of Midodrine :
>10%
Paresthesia (18%)
Piloerection (13%)
Pruritus (13%)
Supine hypertension (7-13%)
Urinary retention or urgency (up to 13%)
1-10%
Chills (5%)
Pain, including abdominal pain (5%)
Rash (2%)
<1%
Anxiety
Canker sore
Confusion
Dizziness
Dry skin
Erythema multiforme
Facial flushing
Flushing
Headache
Hyperesthesia
Insomnia
Intracranial pressure increased
Nausea
Somnolence
Weakness
Xerostomia
Mechanism of Action
Midodrine, a direct-acting sympathomimetic amine, is a prodrug which forms an active metabolite, desglymidodrine. It selectively activates the α1-adrenergic receptors of the arteriolar and venous vasculature, producing peripheral vasoconstriction and elevation of BP.