Trade Names:Levatol- Tablets 20 mg
Nonselectively blocks beta-adrenergic receptors, primarily affecting the CV system (eg, decreased heart rate, decreased cardiac contractility, decreased BP) and lungs (promotes bronchospasm).
Absorption is rapid and complete (100%). The t max is 2 to 3 h.
Protein binding is 80% to 98%. Penbutolol crosses the placenta.
Hepatic metabolism is by conjugation and oxidation.
Urine (90% excreted in urine, 1/ 6 as penbutolol conjugate). Penbutolol plasma t ½ is approximately 5 h; conjugated penbutolol is approximately 20 h, 25 h in elderly patients, and approximately 100 h in patients on renal dialysis.
Accumulation of penbutolol conjugates may be expected.
Management of mild to moderate hypertension.
Greater than first-degree heart block; CHF unless secondary to tachyarrhythmia or untreated hypertension treatable with beta-blockers; overt cardiac failure; sinus bradycardia; cardiogenic shock; hypersensitivity to beta-blockers; untreated bronchial asthma or bronchospasm, including severe COPD.
PO 20 mg every day.
Administer without regard to meals. Administer with food if GI upset occurs.
Store tablets at controlled room temperature (59° to 86°F). Protect from light.
May attenuate or reverse antihypertensive effect; potentially life-threatening increases in BP, especially on withdrawal.Epinephrine
Initial hypertensive episodes followed by bradycardia may occur.Ergot derivatives
Peripheral ischemia, manifested by cold extremities and possible gangrene.Insulin
Prolonged hypoglycemia with masking of symptoms.Lidocaine
Increased lidocaine levels, leading to toxicity.NSAIDs
Some agents may impair antihypertensive effects.Theophylline
Elimination of theophylline may be reduced; effects of both drugs may be reduced by pharmacologic antagonism.Verapamil
Effects of both drugs may be increased.
None well documented.
Bradycardia; hypotension; CHF; edema; worsening angina, atrioventricular (AV) block.
Dizziness; tiredness; fatigue; headache; insomnia; depression; short-term memory loss; emotional lability.
Dry eyes; visual disturbances.
Diarrhea; nausea; dyspepsia.
Agranulocytosis; nonthrombocytopenic and thrombocytopenic purpura.
May increase or decrease blood sugar.
Cough; dyspnea; bronchospasm.
Category C .
Safety and efficacy not established.
Administer cautiously in CHF patients controlled by digitalis and diuretics.
May mask signs and symptoms of hypoglycemia (eg, tachycardia, BP changes). May potentiate insulin-induced hypoglycemia.
Give drug with caution to patients with bronchospastic disease.
May mask clinical signs of developing or continuing hyperthyroidism (eg, tachycardia). Abrupt withdrawal may exacerbate symptoms of hyperthyroidism, including thyroid storm.
A beta-blocker withdrawal syndrome (eg, hypertension, tachycardia, anxiety, angina, MI) may occur 1 to 2 wk after sudden discontinuation of systemic beta-blockers. If possible, gradually withdraw therapy over 1 to 2 wk.
May be unresponsive to usual doses of epinephrine; aggressive therapy may be required.
May precipitate or aggravate symptoms of arterial insufficiency.
Bradycardia, hypotension, CHF, AV block, intraventricular conduction defects, asystole, coma.
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