Ritodrine
Contraindicated
Textbook
Reduced efficacy of ritodrine and potential for adverse cardiovascular effects.
Ritodrine should not be used if the mother is receiving beta blockers.
Source: KDT 7e · p333
Drug reference
Penbutolol
Beta Blocker · Unknown
Beta BlockerUnknown
CDSCO approvedSchedule H
EXCRETION
—
not curated
INTERACTIONS
12 major
incl. contraindicated
PREGNANCY
—
not curated
Top interactionssee all 12 →
- RitodrineContraindicatedTextbookKDT 7e · p333
- AdrenalineSevereTextbookKDT 7e · p133
- AmilorideSevereTextbookKDT 7e
- MethacholineSevereTextbookG&G 14e · p212
Mechanism
Penbutolol is a non-selective beta-adrenergic receptor antagonist, blocking both β1 and β2 adrenoceptors. This blockade results in decreased heart rate and myocardial contractility due to β1 receptor antagonism, and can lead to effects like bronchoconstriction via β2 receptor antagonism.
Drug interactions
Adrenaline
Severe
Textbook
Marked rise in BP.
Adrenaline should not be given to patients receiving β blockers.
Source: KDT 7e · p133
Amiloride
Severe
Textbook
Hyperkalaemia more likely.
Source: KDT 7e
Methacholine
Severe
Textbook
Exaggerated or prolonged bronchoconstriction and reduction in vital capacity in response to methacholine.
Emergency resuscitation equipment, oxygen, and medications to treat severe bronchospasm (e.g., β2 adrenergic receptor agonists for inhalation) should be available during testing.
Source: G&G 14e · p212
Sofosbuvir
Severe
Textbook
Severe bradycardia.
Extreme caution advised if amiodarone is co-administered with sofosbuvir and a beta blocker.
Source: Harrison 22e · unknown
Triamterene
Severe
Textbook
Hyperkalaemia more likely.
Source: KDT 7e
Aminophylline
Severe
Database
Drug interaction classified as: antagonism
Source: DDInter
Arformoterol
Severe
Database
Drug interaction classified as: antagonism
Source: DDInter
Atazanavir
Severe
Database
Drug interaction classified as: synergy
Source: DDInter
Ceritinib
Severe
Database
Drug interaction classified as: synergy
Source: DDInter
Clonidine
Severe
Database
Drug interaction classified as: synergy
Source: DDInter
Diltiazem
Severe
Database
Increased propensity for AV block, severe bradycardia, and decreased left ventricular function.
Avoid concurrent administration. The concurrent administration of diltiazem with a beta blocker is contraindicated.
Source: DDInter
Related guidelines
Other Beta Blocker drugs
Ask House about Penbutolol
Continue into a citation-backed clinical answer with the drug context already attached.
Sources: Katzung·Verified: 2026-05-10 · House clinical team