Reversal of Ketamine Pharmacodynamic Effects With Naloxone

Naloxone Block of Low-dose (Analgetic Dose) Ketamine

Status

Terminated

Phases

Phase 4

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT00921765

Enrollment

Registered

2009-06-16

Start date

2009-12-31

Completion date

2017-12-31

Last updated

2018-04-05

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

Conditions

Pain

Keywords

Pain, Naloxone, Ketamine, Third Molar, Surgery

Brief summary

The purpose of this study is to determine whether the analgetic and other effects effect of ketamine are partly mediated through opioid receptors

Detailed description

Ketamine er et dissociative anaesthetic closely related with phencyclidine (PCP). Phencyclidine is a non-competitive NMDA-antagonist, and it is assumed that the pharmacodynamic mechanism of action for ketamine is the same. Receptor binding studies shows that ketamine has affinity to many receptor types, including opioid mu and kappa receptors. Ketamine has only about 25 times lower affinity for kappa receptors than for the NMDA-receptor complex. Naloxone is a specific antagonist for opioid receptors and block both mu og kappa receptors. A dose of naloxone 10 times larger than required to block mu receptors is required to block kappa receptors. Experiments with naloxone suggest that ketamine is not a mu agonist, but experiments with sufficient large naloxone doses to block kappa receptors have not been carried out in humans.

Interventions

DRUGSaline

Saline single bolus dose followed by saline single bolus dose iv

DRUGSaline + Ketamine

Single bolus dose of saline followed by ketamine 0.2 mg/kg bw

DRUGNaloxone + Placebo

Single bolus dose of naloxone 0.2 mg/kg bw followed by single bolus dose of saline

DRUGNaloxone + Ketamine

Single bolus dose of naloxone 0.2 mg/kg bw followed by single bolus dose of ketamine 0.2 mg/kg bw

Study design

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

BASIC_SCIENCE

Masking

QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Masking description

Double blind (one making drug solutions) another administrating the drugs

Intervention model description

Parallell Group design should be used when final dose had been found

Eligibility

Sex/Gender

FEMALE

Age

18 Years to 30 Years

Healthy volunteers

Inclusion criteria

* Females of norwegian Caucasian origin who needs surgical removal of impacted third molars

Exclusion criteria

* Anamnestic information regarding psychiatric diagnosis regarding mother/father or brother/sister Concommitant medication other than oral contraceptives Hypersensitivity towards NSAID/opioids/study drugs Females with suspected or confirmed pregnancy Lactating females Surgery lasting more than 60 minutes

Design outcomes

Primary

Measure	Time frame
Pain intensity (0-10 Numerical Rating Scale)	30 minutes

Secondary

Measure	Time frame
Subjective measurement of psychotomimetic effects	30 minutes
Adverse effects	30 minutes

Countries

Norway

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026