midodrine hydrochloride(redirected from Orvaten)
Amatine (CA), Apo-Midodrine (CA), Orvaten, ProAmatine
Pharmacologic class: Alpha1-adrenergic agonist
Therapeutic class: Antihypotensive, vasopressor
Pregnancy risk category C
FDA Box Warning
• Drug can markedly increase supine blood pressure, and should be used in patients whose lives are considerably impaired despite standard clinical care. Indication for its use in treating symptomatic orthostatic hypotension rests mainly on an increase in systolic pressure measured 1 minute after standing. Currently, drug's clinical benefits (mainly improved ability to perform activities of daily living) haven't been verified.
Forms active metabolite, desglymidodrine, an alpha1-adrenergic agonist that activates alpha-adrenergic receptors in arteriolar and venous vasculature. This effect increases vascular resistance and ultimately raises blood pressure.
Tablets: 2.5 mg, 5 mg
⊘Indications and dosages
➣ Symptomatic orthostatic hypotension
Adults: 10 mg P.O. t.i.d. during daytime hours with patient in upright position. Give first dose when patient arises in morning, second dose at midday, and third dose in late afternoon.
• Renal impairment
• Severe coronary artery disease or organic heart disease
• Acute renal disease, urinary retention
• Persistent, excessive supine hypertension
Use cautiously in:
• renal or hepatic impairment, diabetes mellitus, vision problems
• pregnant or breastfeeding patients.
• Don't give within 4 hours of bedtime.
CV: vasodilation, bradycardia, supine hypertension
GI: abdominal pain, dry mouth
GU: urinary retention, frequency, or urgency
Skin: rash, pruritus, piloerection
Other: chills, increased pain
Drug-drug.Alpha- and beta-adrenergic blockers, cardiac glycosides, steroids: increased risk of bradycardia, atrioventricular block
Alpha-adrenergic blockers, fludrocortisone: increased risk of supine hypertension
• Monitor supine and sitting blood pressures closely. Report marked rise in supine blood pressure.
• Stay alert for paresthesias.
• Monitor kidney function studies and fluid intake and output. Watch for urinary frequency, urgency, or retention.
☞ Instruct patient to take while in upright position.
• Tell patient to take first dose as soon as he arises for the day, second dose at midday, and third dose in late afternoon (before 6 P.M.). Stress that doses must be taken at least 3 hours apart. Advise patient not to take drug after dinner or within 4 hours of bedtime.
☞ Instruct patient to promptly report symptoms of supine hypertension (pounding in ears, blurred vision, headache).
• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration, vision, and alertness.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs mentioned above.