Alpha-2 Agonist·Cardiovascular - Vasodilators

Clonidine

Hypertension, menopausal flushing, migraine prophylaxis

PBSALPHA-2Catapres, DixaritTablets (100 mcg, 150 mcg),…S4+1

No source link confirmed for this record yet. Its own source notes are under Additional.

At a glance

Max Dose

900 mcg/day

Half-life

12–16 h

Caution: Rebound HTN

HIGH

Caution: Sedation

COMMON

Cautions

Avoid / Cautions

Severe bradycardia, heart block (unless paced). Pregnancy Category B3.

Where it stands

Rapid Summary

Overview

Central alpha-2 agonist that acts on the brainstem to turn off sympathetic outflow. Highly effective but fraught with severe rebound hypertension upon withdrawal.

Clinical Focus

Never cease abruptly. Must be tapered over 7-10 days to avoid a fatal hypertensive crisis.

Bottom Line

Clonidine is a centrally-acting adjunct for resistant hypertension, opioid withdrawal, and ADHD, but abrupt cessation causes dangerous rebound hypertensive crises.

Formulation & Access

Brand Names

Catapres, Dixarit

Oral Routes

Tablets (100 mcg, 150 mcg), Dixarit (25 mcg). Note microgram dosing!

Parenteral

Ampoule (150 mcg/1 mL) for IV use (Rare, Specialist only).

Prescribing & PBS

Unrestricted General Benefit (S4).

Indications & Use

Primary

PBSTGA

Hypertension, menopausal flushing, migraine prophylaxis.

Off-Label

OFF

Withdrawal syndromes, severe acute agitation, ADHD in children.

Clinical Place

Last-line for hypertension. Highly useful in toxicology/psychiatry for hyperadrenergic states.

Quick reference

Class & Role

Alpha-2 Agonist — Central alpha-2 agonist that acts on the brainstem to turn off sympathetic outflow.

Route / Formulation

Tablets (100 mcg, 150 mcg), Dixarit (25 mcg). Note microgram dosing! (Catapres, Dixarit)

Usual Dose & Max

PO 50–100 mcg BD to TDS. Max 900 mcg/day.

Key Indication Doses

Resistant HTN: PO 50–100 mcg BD to TDS. Max 900 mcg/day. Opiate/Alcohol Withdrawal: PO 100-150 mcg TDS (Short-term, off-label). Agitation / Delirium: PO 50 mcg PRN (Off-label). Elderly / Frail: Start at 25-50 mcg BD.

Best Uses

Clonidine is a centrally-acting adjunct for resistant hypertension, opioid withdrawal, and ADHD, but abrupt cessation causes dangerous rebound hypertensive crises.

Key Risks

Neurological: Sedation, drowsiness, depression, vivid dreams. Gastrointestinal: Dry mouth, severe constipation. Cardiovascular: Bradycardia, orthostatic hypotension. CRITICAL — Rebound hypertensive crisis upon sudden cessation.

Key Interactions

Beta-blockers. Combining them massively increases the severity of rebound hypertension if Clonidine is missed/ceased (Beta-blockers leave alpha vasoconstriction unopposed). Additive sedation with alcohol, benzos, and antipsychotics.

Monitoring

Strict BP and HR monitoring. Ensure doses are not missed. No specific routine laboratory tests required.

Clinical Pearl

Missing even 1 or 2 doses can cause a massive catecholamine surge leading to stroke or MI. If a patient is NBM for surgery, Clonidine MUST be converted to IV/patch to prevent crisis.

Access

Catapres, DixaritTablets (100 mcg, 150 mcg),…

Brand: Catapres, Dixarit
Formulation: Tablets (100 mcg, 150 mcg), Dixarit (25 mcg). Note microgram dosing!

From this page

No calculator, monitoring schedule or factsheet is linked to this medicine page yet.

Alpha-2 Agonist·Cardiovascular - Vasodilators

Clonidine

Hypertension, menopausal flushing, migraine prophylaxis

PBSALPHA-2Catapres, DixaritTablets (100 mcg, 150 mcg),…S4+1

No source link confirmed for this record yet. Its own source notes are under Additional.

At a glance

Max Dose

900 mcg/day

Half-life

12–16 h

Caution: Rebound HTN

HIGH

Caution: Sedation

COMMON

Cautions

Avoid / Cautions

Severe bradycardia, heart block (unless paced). Pregnancy Category B3.

Where it stands

Rapid Summary

Overview

Central alpha-2 agonist that acts on the brainstem to turn off sympathetic outflow. Highly effective but fraught with severe rebound hypertension upon withdrawal.

Clinical Focus

Never cease abruptly. Must be tapered over 7-10 days to avoid a fatal hypertensive crisis.

Bottom Line

Clonidine is a centrally-acting adjunct for resistant hypertension, opioid withdrawal, and ADHD, but abrupt cessation causes dangerous rebound hypertensive crises.

Formulation & Access

Brand Names

Catapres, Dixarit

Oral Routes

Tablets (100 mcg, 150 mcg), Dixarit (25 mcg). Note microgram dosing!

Parenteral

Ampoule (150 mcg/1 mL) for IV use (Rare, Specialist only).

Prescribing & PBS

Unrestricted General Benefit (S4).

Indications & Use

Primary

PBSTGA

Hypertension, menopausal flushing, migraine prophylaxis.

Off-Label

OFF

Withdrawal syndromes, severe acute agitation, ADHD in children.

Clinical Place

Last-line for hypertension. Highly useful in toxicology/psychiatry for hyperadrenergic states.

Quick reference

Class & Role

Alpha-2 Agonist — Central alpha-2 agonist that acts on the brainstem to turn off sympathetic outflow.

Route / Formulation

Tablets (100 mcg, 150 mcg), Dixarit (25 mcg). Note microgram dosing! (Catapres, Dixarit)

Usual Dose & Max

PO 50–100 mcg BD to TDS. Max 900 mcg/day.

Key Indication Doses

Best Uses

Clonidine is a centrally-acting adjunct for resistant hypertension, opioid withdrawal, and ADHD, but abrupt cessation causes dangerous rebound hypertensive crises.

Key Risks

Key Interactions

Monitoring

Strict BP and HR monitoring. Ensure doses are not missed. No specific routine laboratory tests required.

Clinical Pearl

Missing even 1 or 2 doses can cause a massive catecholamine surge leading to stroke or MI. If a patient is NBM for surgery, Clonidine MUST be converted to IV/patch to prevent crisis.

Access

Catapres, DixaritTablets (100 mcg, 150 mcg),…

Brand: Catapres, Dixarit
Formulation: Tablets (100 mcg, 150 mcg), Dixarit (25 mcg). Note microgram dosing!

From this page

No calculator, monitoring schedule or factsheet is linked to this medicine page yet.