Astemizole
Astemizole is a second-generation antihistamine that was formerly used to treat seasonal allergic rhinitis and chronic idiopathic urticaria. It works by selectively blocking H1 histamine receptors, reducing allergic symptoms such as sneezing, itching, and runny nose. Due to safety concerns regarding cardiac arrhythmias, this medication has been withdrawn from markets in many countries.
Astemizole is a discontinued antihistamine that was used for allergies but was removed from the market due to serious cardiac risks.
Key facts at a glance
- ATC
- R06AX11
- RxNorm
- 42328
- Generic
- Astemizole
- Class
- atc-r06
- Brands
- —
- Availability
- rx
- Lactation
- unknown
- Routes
- oral
- Forms
- tablet
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Dosage and administration
- Usual dose
- 500mg twice daily
- Maximum
- consult physician
- Frequency
- every 12 hours
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 250mg twice daily
- Maximum
- consult physician
- Frequency
- every 12 hours
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 400mg daily
- Maximum
- consult physician
- Frequency
- once daily
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
Overdose information
Special Populations
8 groupspregnancy
first trimesteravoid
avoid use during pregnancy due to potential risks to fetus
regular fetal monitoring if exposure occurs
Use of this medication in this population requires careful consideration of risks and benefits.
pregnancy
second trimesteravoid
avoid use during pregnancy unless benefits outweigh risks
regular fetal monitoring
Use of this medication in this population requires careful consideration of risks and benefits.
pregnancy
third trimesteravoid
avoid use near term due to potential neonatal effects
fetal and neonatal monitoring
Use of this medication in this population requires careful consideration of risks and benefits.
pediatric_age
children under 12not applicable
drug withdrawn from market, not recommended for pediatric use
not applicable
Use of this medication in this population requires careful consideration of risks and benefits.
geriatric
elderly 65 years and olderavoid
avoid use in elderly due to increased cardiac risk and QT prolongation
cardiac monitoring if exposed
Use of this medication in this population requires careful consideration of risks and benefits.
renal_impairment
severe renal impairmentavoid
avoid in patients with severe renal impairment due to drug accumulation risk
renal function monitoring
Use of this medication in this population requires careful consideration of risks and benefits.
hepatic_impairment
severe hepatic impairmentcontraindicated
contraindicated in hepatic impairment due to extensive hepatic metabolism and increased cardiac risk
liver function tests
Use of this medication in this population requires careful consideration of risks and benefits.
lactation
breastfeedingavoid
avoid breastfeeding during treatment, drug excreted in breast milk
infant monitoring if exposure occurs
Use of this medication in this population requires careful consideration of risks and benefits.
Statistics and clinical data
Commonly prescribed since
General prescribing information
Drug class
Drug class information
Common uses
Common therapeutic uses
Market withdrawal
Safety concerns
Astemizole was prescribed for the symptomatic relief of seasonal allergic rhinitis (hay fever), perennial allergic rhinitis, and chronic idiopathic urticaria (hives). It was used to alleviate symptoms including sneezing, rhinorrhea, nasal itching, ocular itching, and skin itching associated with allergic conditions.
Astemizole is a selective, long-acting H1-receptor antagonist that competitively blocks histamine at H1 receptor sites. By preventing histamine from binding to these receptors, it inhibits the inflammatory and allergic responses that histamine triggers, thereby reducing allergy symptoms.
Astemizole has been withdrawn from the US market and many other countries due to documented cases of serious cardiac arrhythmias, including QT prolongation and torsades de pointes, particularly when used with CYP3A4 inhibitors or in overdose. It has been replaced by safer antihistamine alternatives. Patients should consult their healthcare provider for current treatment options.
Contraindications
Conditions and patient states where this medication should be avoided or used with caution.
Do not use (1)
Known allergy to this medication or its components
Use caution (1)
Consult healthcare provider for benefits vs risks assessment
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 20, 2026. · Read our editorial policy