Trade Names:Hylorel- Tablets 10 mg- Tablets 25 mg
Inhibits vasoconstriction by restraining norepinephrine release from nerve storage sites; depletion of norepinephrine causes relaxation of vascular smooth muscle, decreasing total peripheral resistance, and venous return.
T max is 1.5 to 2 h.
T 1/ 2 is about 10 h. About 85% is excreted in the urine, about 40% as unchanged drug.
Total Cl decreases and t 1/ 2 is prolonged. Dosage adjustment may be necessary.
Treatment of hypertension in patients not responding adequately to thiazide-type diuretics.
Pheochromocytoma; concurrent use or use within 1 wk of MAOIs; frank CHF.
PO 10 mg/day (5 mg twice daily) initially. Maintenance dose: PO 20 to 75 mg/day, usually in 2 divided doses; 3 or 4 times daily dosing may be needed. In patients with renal function impairment, dosage adjustment may be necessary.
Store at room temperature.
Effects of guanadrel may be potentiated, resulting in excessive orthostatic hypotension and bradycardia.Indirect-acting sympathomimetics (eg, ephedrine)
Reverse antihypertensive effect.MAOIs, phenothiazines, tricyclic antidepressants
Inhibit antihypertensive effect.
None well documented.
Palpitations; chest pain; peripheral edema; orthostatic hypotension; syncope.
Fatigue; headache; faintness; drowsiness; paresthesias; confusion; depression; sleep disorders.
Dilated pupils; visual disturbances; glossitis.
Increased bowel movements; gas pain/indigestion; constipation; anorexia; nausea or vomiting; abdominal distress or pain.
Nocturia; urination urgency or frequency; ejaculation disturbances; impotence; hematuria; decreased urine output.
Shortness of breath; coughing.
Excessive weight loss or gain; aching limbs; leg cramps; back or neckache; joint pain or inflammation; gangrene.
Category B .
Safety and efficacy not established.
Drug may aggravate asthma because of depletion of catecholamines; drugs used to treat asthma may reduce hypotensive effect of guanadrel.
Discontinue 48 to 72 h before elective surgery to prevent vascular collapse during anesthesia; for emergency surgery, preanesthetic and anesthetic agents are administered in reduced dosage.
Marked dizziness, blurred vision, syncope, orthostatic hypotension.
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