Does adding clonidin to a local anesthetic prolong the duration of a nerve block?

Does perineural clonidin prolong the duration of an adductor canal block when controlling for a systemic effect? - a randomized, blinded, paired study in healthy volunteers.

Status

Active, not recruiting

Phases

Phase 2

Study type

Interventional

Source

EU CTR

Registry ID

EUCTR2014-005640-18-DK

Enrollment

Registered

2015-01-08

Start date

2015-07-21

Completion date

Unknown

Last updated

2021-08-10

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Healthy volunteers (treatment intended for pain treatment in patients after knee surgery) MedDRA version: 18.0 Level: LLT Classification code 10054711 Term: Postoperative pain System Organ Class: 100000004863

Interventions

Trade Name: Catapresan Product Name: Catapresan Pharmaceutical Form: Solution for injection INN or Proposed INN: CLONIDINE CAS Number: 4205-90-7 Concentration unit: µg/ml microgram(s)/millilitre Conce

Eligibility

Sex/Gender

Male

Inclusion criteria

Inclusion criteria: Age >18 Men ASA 1 BMI >18 and =65 years) yes F.1.3.1 Number of subjects for this age range 21

Exclusion criteria

Exclusion criteria: Allergy to study medication Alkoholconsumption > 21 unit sof alcohol per week Medical abuse (judged by the investigator) Daily intake of perscription painkillers within 4 weeks Intake of over the counter medication within 48 hours Earlier trauma og surgery to lower limb Diabetes mellitus Heart block 2. og 3. degree Sick sinus node Failed blocks will be excluded from the paired analysis (no sensory change and therefore zero duration) but partial blocks (Defined as loss of cold sensation (alcohol swab) and pin-prick at t=2h but VAS > 0 during tonic heat stimulation test at t=2h) will be included in ITT but not PPA.

Design outcomes

Primary

Measure	Time frame
Main Objective: To investigate whether clonidine as an adjuvant to ropivacaine for adductor canal block increases duration of the sensory block when controlling for a systemic effect;Secondary Objective: Not applicable;Primary end point(s): Difference in duration of sensory block between clonidine and placebo assessed as cold sensation with an alcohol swab.;Timepoint(s) of evaluation of this end point: Duration is defined as time from block performance until recovery of normal sensation to an alcohol swab, assessed every hour post block (and every half hour when pain scores during the tonic heat stimulation test is above zero ). Time for sleep will be provided if necessary.	—

Measure

Time frame

Main Objective: To investigate whether clonidine as an adjuvant to ropivacaine for adductor canal block increases duration of the sensory block when controlling for a systemic effect;Secondary Objective: Not applicable;Primary end point(s): Difference in duration of sensory block between clonidine and placebo assessed as cold sensation with an alcohol swab.;Timepoint(s) of evaluation of this end point: Duration is defined as time from block performance until recovery of normal sensation to an alcohol swab, assessed every hour post block (and every half hour when pain scores during the tonic heat stimulation test is above zero ). Time for sleep will be provided if necessary.

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Secondary

Measure	Time frame
Secondary end point(s): Difference between clonidine and placebo and the duration of the sensory block assessed by: - Pin prick - Maximum pain during tonic heat stimulation test - Warmth detection threshold - Heat pain detection threshold Difference in maximum pain scores between clonidin and placebo during block and after recovery of normal sensation.;Timepoint(s) of evaluation of this end point: Duration is defined as time from block performance until recovery of normal sensation, assessed on the hour postblock. Except warmth- and heat pain detection thresholds which are only assessed when pain scores during tonic heat stimulation is above zero. Recovery of normal sensation is defined as VAS pain scores return to baseline or maximum 9 mm below and detection thresholds return to baseline or less than + 2 degrees above. Difference in maximum pain scores will be assessed at 4 hours post block and one hour after pain scores have returned to the preblock values. Time for sleep will be provided if necessary.	—

Measure

Time frame

Secondary end point(s): Difference between clonidine and placebo and the duration of the sensory block assessed by: - Pin prick - Maximum pain during tonic heat stimulation test - Warmth detection threshold - Heat pain detection threshold Difference in maximum pain scores between clonidin and placebo during block and after recovery of normal sensation.;Timepoint(s) of evaluation of this end point: Duration is defined as time from block performance until recovery of normal sensation, assessed on the hour postblock. Except warmth- and heat pain detection thresholds which are only assessed when pain scores during tonic heat stimulation is above zero. Recovery of normal sensation is defined as VAS pain scores return to baseline or maximum 9 mm below and detection thresholds return to baseline or less than + 2 degrees above. Difference in maximum pain scores will be assessed at 4 hours post block and one hour after pain scores have returned to the preblock values. Time for sleep will be provided if necessary.

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Countries

Denmark

Contacts

Public ContactClinical trials information

Køge Sygehus

Hessel@dadlnet.dk004560610666

Outcome results

None listed

Source: EU CTR (via WHO ICTRP) · Data processed: Feb 4, 2026