Clonidine

Legal status and availability in the UK

Clonidine is a prescription-only medicine (POM) in the UK.

In our online pharmacy, clonidine is available without a prescription, with discreet delivery to the United Kingdom in 5‑14 days.

Basic clonidine information

• INN (international nonproprietary name): Clonidine (as clonidine hydrochloride)
• Brand names available in the United Kingdom: Catapres; generic clonidine tablets
• ATC code: C02AC01 (antihypertensives, imidazoline derivatives)
• Forms and dosages: Tablets; injection for hospital use
• Registration status in the United Kingdom: Licensed by the MHRA; prescription-only medicine
• OTC / Rx classification: Prescription-only medicine (POM)

Licensed and off‑label indications

Primary licensed uses

Which conditions is clonidine licensed to treat?

Clonidine’s primary licensed indication is hypertension, classed under ATC code C02AC01 as a central antihypertensive.

Common off‑label/adjunct uses

Clinicians commonly use clonidine off‑label for alcohol and opioid withdrawal as part of supervised detox protocols.

Other off‑label roles include perioperative haemodynamic control and adjunctive migraine therapy.

Hypertension →

Short‑acting oral tablets for chronic control.

Withdrawal →

Short‑acting oral dosing for symptom control over days to weeks.

Brands and forms

In the UK, clonidine is supplied as tablets (Catapres and generic clonidine) and as an injection for hospital use.

Dosage guidance and practical titration (by condition)

Hypertension and chronic treatment

A typical starting oral dose for adult hypertension is 0.1 mg twice daily, titrated by 0.1 mg every 1–2 weeks as directed by the prescriber.

Elderly patients should start lower, for example 0.05 mg twice daily, and titrate more slowly while monitoring blood pressure and symptoms.

Withdrawal

For opioid or alcohol withdrawal, short‑term regimens commonly use 0.1–0.2 mg every 4–6 hours tailored to symptoms and monitored by clinicians.

Dosing must be individualised and supervised by a GP or specialist, especially in renal or hepatic impairment.

Administration tips

Oral tablets

How should oral clonidine be taken?

Swallow tablets with water.

If a dose is missed, take as soon as remembered unless the next dose is due soon; do not double the next dose.

Titration strategies and discontinuation precautions

Gradual up‑titration best practice

Which titration strategy minimises side effects?

Start low and increase slowly, particularly in older adults and those with cardiac or renal disease.

For hypertension, begin at 0.1 mg twice daily and increase by 0.1 mg every 1–2 weeks while monitoring blood pressure and symptoms.

Withdrawal, rebound hypertension and emergencies

Abrupt discontinuation can cause rebound hypertension, tachycardia, agitation and headache, so a gradual taper under clinician supervision is advised.

A practical taper example is to reduce the daily dose by 10–25% every few days depending on the clinical situation and to monitor blood pressure during the taper.

Overdose or severe withdrawal requires urgent medical assessment; overdose signs include profound hypotension, bradycardia and CNS depression.

Activated charcoal may be considered for early oral overdose presentations as advised by emergency clinicians.

Side‑effect profile and practical management advice

Common, transient side effects and coping tips

What side effects should patients expect and how can they be managed?

Common effects include dry mouth, drowsiness or sedation, dizziness, constipation and weakness.

Take initial doses at bedtime to reduce daytime drowsiness and avoid driving until effects are known.

Use sugar‑free gum or frequent sips of water for dry mouth and change position slowly to reduce orthostatic dizziness.

When to seek medical attention

Seek urgent medical care for syncope, severe bradycardia, chest pain, severe shortness of breath or profound lethargy that could indicate significant hypotension.

Report suspected adverse reactions through the Yellow Card scheme as part of UK pharmacovigilance.

• Practical counselling tips:
• Take doses at bedtime where advised, keep hydrated for dry mouth and take care with alcohol and other CNS depressants.

Contraindications and interactions

Absolute and relative contraindications

Who should not take clonidine?

Absolute contraindications include hypersensitivity to clonidine or its excipients and severe bradyarrhythmias or advanced AV block without pacemaker support.

Relative cautions include severe coronary artery disease, renal impairment, elderly patients and those with significant depression.

Key drug interactions

Important interactions include additive CNS depression with benzodiazepines, opioids and alcohol, and enhanced hypotension when combined with other antihypertensives such as beta‑blockers or ACE inhibitors.

Tricyclic antidepressants and MAO inhibitors can alter clonidine’s autonomic effects and require careful clinical review.

Dosing and safety in vulnerable groups

Elderly, renal/hepatic impairment and pregnancy notes

Elderly patients should start at reduced doses such as 0.05 mg twice daily and titrate slowly because of orthostatic hypotension and fall risk.

Renal impairment requires dose reduction as clonidine is partly renally excreted and can increase CNS depression.

Use in pregnancy should be considered only if benefits outweigh risks and under obstetric supervision.

For breastfeeding, discuss risks and benefits and monitor infants for sedation if clonidine is used by the mother.

• Quick‑reference dosing bullets:
• Elderly: start at 0.05 mg BID and titrate slowly.
• Renal impairment: reduce dose and monitor for CNS effects.

What to monitor and when

Baseline assessments and routine checks

Before starting clonidine, record baseline blood pressure and heart rate and consider ECG if bradyarrhythmia is suspected.

Check renal and hepatic function where clinically indicated and document current medications and fall risk.

During titration for hypertension, monitor blood pressure and symptoms every 1–2 weeks until stable.

When to refer or adjust therapy

Refer to specialists if severe hypotension, bradycardia, syncope, significant mood changes or suspected overdose occur.

Storage

Tablets should be stored at room temperature, typically 15–30°C, and protected from moisture.

Do not flush tablets down the toilet; return unused medicines to a pharmacy for safe disposal.

Choosing clonidine: alternatives

Main pharmacological alternatives (clinical comparison)

Which medicines are commonly chosen instead of clonidine?

For hypertension the main alternatives include ACE inhibitors, beta‑blockers, calcium‑channel blockers and methyldopa depending on patient comorbidities.

For withdrawal management, clonidine is one adjunct among other supportive measures and medications chosen by the treating service.

Delivery across the United Kingdom