Drug | Dose | Pharmacokinetic considerations | Mechanism of action | Major side effects and precautions |
Approved for orthostatic hypotension | ||||
Midodrine | 2.5 to 10 mg up to 3 times daily. Administer in the morning, midday, and/or 3 to 4 hours before bedtime; individualize to patient need. | Short acting (peak effect 1 hour; duration 2 to 3 hours). | Alpha-1-adrenergic receptor agonist | Supine hypertension, piloerection ("goose flesh"), scalp itching, urinary retention. Use with caution in patients with congestive heart failure and chronic renal failure. |
Droxidopa | 100 to 600 mg up to 3 times daily. Administer in the morning, midday, and/or 3 to 4 hours before bedtime; individualize to patient need. | Short acting (peak effect 3.5 hours; duration 5 to 6 hours). | Synthetic norepinephrine precursor | Supine hypertension, headache, nausea, fatigue. Use with caution in patients with congestive heart failure and chronic renal failure. |
Not specifically approved for orthostatic hypotension | ||||
Atomoxetine | 10 to 18 mg 2 times daily. | Short acting. Most effective for patients with central autonomic dysfunction. | Norepinephrine reuptake inhibitor | Supine hypertension, insomnia, irritability, decreased appetite. |
Fludrocortisone | 0.05 to 0.2 mg once daily in the morning. Doses >0.2 mg/day are not more effective and have greater adverse effects. | Long acting. Clinical effect is observed after ≥7 days of treatment. | Synthetic mineralocorticoid, volume expander that increases sodium and water reabsorption | Short-term use: Supine hypertension, hypokalemia*, edema. Long-term use: Hypertension and target organ damage (eg, left ventricular hypertrophy), renal failure. Use with caution in patients with congestive heart failure. |
Pyridostigmine | 30 to 60 mg 2 or 3 times daily. | Short acting. | Acetylcholinesterase inhibitor | Abdominal cramps, diarrhea, sialorrhea, excessive sweating, urinary incontinence. |