Clarithromycin
Contraindicated
Textbook-cited
Dangerous ventricular arrhythmia (QT prolongation, torsades de pointes)
Concurrent use is contraindicated
Source: KDT 7e · p948
Drug reference
astemizole
Drug monograph
CDSCO approved
EXCRETION
—
not curated
INTERACTIONS
12 major
incl. contraindicated
PREGNANCY
—
not curated
Top interactionssee all 12 →
- ClarithromycinContraindicatedTextbook-citedKDT 7e · p948
- ErythromycinContraindicatedTextbook-citedKDT 7e · p948
- FluconazoleContraindicatedTextbook-citedKDT 7e · p948
- ItraconazoleContraindicatedTextbook-citedKDT 7e · p948
Mechanism
Not yet extracted
Pharmacokinetics
Metabolism
Astemizole is a substrate of CYP3A4/5.
Drug interactions
Erythromycin
Contraindicated
Textbook-cited
Dangerous ventricular arrhythmia (QT prolongation, torsades de pointes)
Concurrent use is contraindicated
Source: KDT 7e · p948
Fluconazole
Contraindicated
Textbook-cited
Dangerous ventricular arrhythmia (QT prolongation, torsades de pointes)
Concurrent use is contraindicated
Source: KDT 7e · p948
Itraconazole
Contraindicated
Textbook-cited
Dangerous ventricular arrhythmia (QT prolongation, torsades de pointes)
Concurrent use is contraindicated
Source: KDT 7e · p948
Ketoconazole
Contraindicated
Textbook-cited
Dangerous ventricular arrhythmia (QT prolongation, torsades de pointes)
Concurrent use is contraindicated
Source: KDT 7e · p948
Artemisinins
Severe
Textbook
Increased risk of cardiac conduction defects.
Source: KDT 7e · p816-835
Adenosine
Severe
Database
Drug interaction classified as: synergy
Source: DDInter
Amiodarone
Severe
Database
Drug interaction classified as: synergy
Source: DDInter
Amisulpride
Severe
Database
Drug interaction classified as: synergy
Source: DDInter
Amprenavir
Severe
Database
Drug interaction classified as: metabolism
Source: DDInter
Anagrelide
Severe
Database
Drug interaction classified as: synergy
Source: DDInter
Aprepitant
Severe
Database
Life-threatening QT prolongation.
Aprepitant is contraindicated in patients receiving astemizole.
Source: DDInter
Other Unclassified drugs
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Sources: KD Tripathi 7e·Verified: 2026-05-10 · House clinical team