Dosing and uses of Levatol (penbutolol)
Adult dosage forms and strengths
tablet
- 20mg
Arterial Hypertension
Initial 10mg PO qDay (full effect after 4-6weeks)
Maintenance dose: 10-40mg PO qDay (full effect after 2 weeks)
No more than 80mg PO qDay
May admininster alone or in combination with other antihypertensive agents
Additional Information
Less effective than thiazide diuretics in black and geriatric patients
Shown to decrease mortality in hypertension and post-myocardial infarction
Pediatric dosage forms and strengths
<18 years old: Safety and efficacy not established
Geriatric dosage forms and strengths
Initial 10mg PO qDay (full effect after 4-6weeks)
Maintenance dose: 10-40mg PO qDay (full effect after 2 weeks)
No more than 80mg PO qDay
May admininster alone or in combination with other antihypertensive agents
Levatol (penbutolol) adverse (side) effects
Frequency not defined
Aggravate CHF
Depression
Fatigue
Mask symptoms of hypoglycemia
May increase triglyceride levels
Decrease HDL (less than other beta blockers)
Bronchospasm
Decreased exercise tolerance
Raynaud's phenomenon
May increase insulin resistance
Warnings
Contraindications
Severe peripheral vascular disease, sinus bradycardia, 2°/3° heart block, cardiogenic shock, hypersensitivity, asthma/COPD, sick sinus syndrome without permanent pacemaker
Cautions
IDDM, CHF, hyperthyroidism, renal impairment, liver disease
Sudden discontinuation can exacerbate angina and lead to myocardial infarction
Increased risk of stroke after surgery, cerebrovascular insufficiency, peripheral vascular disease, anesthesia/surgery (myocardial depression), use in pheochromocytoma
Anesthesia/surgery (myocardial depression): chronically administered beta-blocking therapy should not be routinely withdrawn prior to major surgery, however the impaired ability of the heart to respond to reflex adrenergic stimuli may augment the risks of general anesthesia and surgical procedures
Pregnancy and lactation
Pregnancy category: C
Lactation: unknown; use with caution
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Levatol (penbutolol)
Mechanism of action
Beta adrenergic receptor blocker; intrinsic sympathomimetic activity (lowers BP with little decrease in HR)
Pharmacokinetics
Half-Life: 5 hr
Peak Plasma: 2-3 hr
Duration: >20 hr
Peak effect: 1.3-3 hr
Protein bound: 80-98%
Metabolism: Liver (oxidation and conjugation)
Excretion: Urine
