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Bethanidine

Published: July 26, 2026Updated: August 20, 2026

Bethanidine is an antihypertensive medication classified as a sympatholytic agent, used primarily to lower blood pressure in patients with moderate to severe hypertension. It functions by depleting norepinephrine from sympathetic nerve terminals, thereby reducing sympathetic tone and causing vasodilation. While once used in clinical practice, it has largely been replaced by newer antihypertensive agents with more favorable side effect profiles.

Quick summary

Bethanidine is an older antihypertensive drug that lowers blood pressure by reducing sympathetic nervous system activity.

Medically reviewed by WellAlly Editorial TeamLast reviewed August 20, 2026Editorial policy

Key facts at a glance

ATC
C02CC01
RxNorm
1523
Generic
Bethanidine
Class
atc-c02
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

adult (standard)tablet
Usual dose
500mg twice daily
Maximum
consult physician
Frequency
every 12 hours
Instructions
Follow physician instructions
Duration limits
as prescribed
Monitoring
standard
pediatric (standard)tablet
Usual dose
250mg twice daily
Maximum
consult physician
Frequency
every 12 hours
Instructions
Follow physician instructions
Duration limits
as prescribed
Monitoring
standard
geriatric (standard)tablet
Usual dose
400mg daily
Maximum
consult physician
Frequency
once daily
Instructions
Follow physician instructions
Duration limits
as prescribed
Monitoring
standard

Overdose information

Important overdose information
Toxic dose: Doses exceeding 2 grams may cause serious toxicity; therapeutic dose range is 50-200 mg daily
Chronic overdose: Prolonged use leading to excessive hypotension and bradycardia
Immediate actions
Activate emergency medical services, place patient in supine position with legs elevated, monitor vital signs, establish IV access for fluid resuscitation
Antidote
No specific antidote available; treatment is supportive(Supportive care is primary treatment approach)
Poison Control: 1-800-222-1222

Special Populations

10 groups
✗

pregnancy

first trimester
unsafe
FDA Category
C
Dose Adjustment

avoid if possible

Key Recommendations

avoid use during pregnancy unless benefits outweigh risks

Monitor

regular fetal monitoring

Use of this medication in this population requires careful consideration of risks and benefits.

✗

pregnancy

second trimester
unsafe
FDA Category
C
Dose Adjustment

avoid if possible

Key Recommendations

discontinue if pregnancy occurs

Monitor

regular fetal monitoring and growth assessment

Use of this medication in this population requires careful consideration of risks and benefits.

✗

pregnancy

third trimester
unsafe
FDA Category
C
Dose Adjustment

avoid

Key Recommendations

avoid use near term due to potential fetal toxicity

Monitor

fetal heart rate monitoring

Use of this medication in this population requires careful consideration of risks and benefits.

✗

lactation

breastfeeding
unsafe
FDA Category
N
Dose Adjustment

avoid

Key Recommendations

do not breastfeed while taking bethanidine

Monitor

monitor infant for hypotension

Use of this medication in this population requires careful consideration of risks and benefits.

⚠

geriatric

elderly
caution
FDA Category
N
Dose Adjustment

start with lower dose

Key Recommendations

use with caution due to increased sensitivity to hypotensive effects

Monitor

monitor blood pressure closely

Use with caution and monitor for adverse effects.

?

pediatric_age

children adolescents
unknown
FDA Category
N
Dose Adjustment

not established

Key Recommendations

not recommended due to limited safety data

Monitor

blood pressure monitoring if used

⚠

renal_impairment

mild
caution
FDA Category
N
Dose Adjustment

reduce dose

Key Recommendations

reduce dose and monitor renal function

Monitor

monitor renal function and blood pressure

Use with caution and monitor for adverse effects.

✗

renal_impairment

severe
unsafe
FDA Category
N
Dose Adjustment

avoid

Key Recommendations

avoid in severe renal impairment

Monitor

monitor renal function

Use of this medication in this population requires careful consideration of risks and benefits.

⚠

hepatic_impairment

mild to moderate
caution
FDA Category
N
Dose Adjustment

reduce dose

Key Recommendations

use with caution, may require dose reduction

Monitor

monitor liver function and blood pressure

Use with caution and monitor for adverse effects.

✗

hepatic_impairment

severe
unsafe
FDA Category
N
Dose Adjustment

avoid

Key Recommendations

avoid in severe hepatic impairment

Monitor

monitor hepatic function

Use of this medication in this population requires careful consideration of risks and benefits.

Statistics and clinical data

prescribingFDA
2023

Market availability

Value:Withdrawn from market

Historical prescribing information

drug_classWHO
2023

Drug class

Value:Antihypertensive (ganglion blocker)

Drug class information

usageMedical guidelines
2023

Historical indication

Value:Severe hypertension

Historical therapeutic uses

eraHistorical medical literature
2023

Primary use period

Value:1950s-1970s

Period of active use

Bethanidine was historically used to treat moderate to severe hypertension, particularly in cases where other antihypertensive medications were insufficient. It has largely fallen out of common clinical use due to the availability of better-tolerated alternatives with fewer side effects.

Bethanidine acts as a false neurotransmitter, being taken up into sympathetic nerve endings and displacing norepinephrine from storage granules. When nerve impulses trigger release, bethanidine is released instead, but it has significantly weaker effects on alpha and beta adrenergic receptors. This results in reduced sympathetic outflow, decreased peripheral vascular resistance, and lowered blood pressure.

Common adverse effects include orthostatic hypotension (especially prominent upon standing), diarrhea, dry mouth, and bradycardia. Due to its mechanism of causing significant blood pressure drops when standing, patients must be carefully monitored. Bethanidine has largely been discontinued in most countries and replaced by more modern antihypertensive agents with improved safety and tolerability profiles.

Contraindications

Conditions and patient states where this medication should be avoided or used with caution.

Do not use (1)

ABSOLUTEhypersensitivity

Known allergy to this medication or its components

Use caution (1)

RELATIVEpregnancy

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.

Medical Disclaimer

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