Mechanism of action: Midodrine balliculeVisual mnemonic: Midodrine mascot “My doe dream” a tilt table is used to evaluate orthostatic intolerance and syncope
What it isAlpha-1 agonist prodrug causing peripheral vasoconstriction; symptomatic orthostatic hypotension.
Why this oneOne of the few agents that reliably raises standing blood pressure, and it does not cross into the CNS.
What limits itSupine hypertension is the limiting problem — never dose within four hours of lying down. Scalp tingling and urinary retention.
BOXED WARNING Can cause marked elevation of supine BP; reserve for symptomatic orthostatic hypotension considerably impairing daily life; clinical benefit (activities of daily living) not verified (approved on surrogate marker)
FDA dosing
Population
Start
Target
Max
Symptomatic orthostatic hypotension
Adult
10 mg TID (daytime, ~4 h apart)
10 mg TID
single doses ≤20 mg studied; >30 mg/day not established
Orthostatic hypotension
Renal impairment
2.5 mg TID
Renal Initiate at 2.5 mg; dose cautiously (desglymidodrine excreted renally)
Hepatic Undefined
Doses may be spaced at 3-h intervals if needed to control symptoms, but not more frequently
Instructions
Dose during daytime upright hours: on arising, midday, and late afternoon (not later than 6 PM)
Do not give after the evening meal or <4 h before bedtime (supine hypertension risk)
Monitor supine and standing BP; stop if supine BP rises excessively; continue only if symptomatic improvement
Available strengths
tab 2.5, 5, 10 mg
Contraindications
Severe organic heart disease
Acute renal disease
Urinary retention
Pheochromocytoma
Thyrotoxicosis
Persistent and excessive supine hypertension
Cautions
Supine hypertension (most serious) — monitor supine/standing BP
Defining liabilityGenerally tolerated at therapeutic doses; clinically important risks are agent-specific and increase with interactions or organ impairment.