Healthy
Conditions
Keywords
PF-02545920, ketamine, fMRI, associative Learning
Brief summary
To evaluate whether PF-02545920 reduces the effects of ketamine on brain activation during causal learning as measured by fMRI compared to placebo in healthy human subjects, and to evaluate whether behavioral measures of abnormal causal learning under ketamine are reduced by treatment with PF 02545920.
Detailed description
The study was terminated on November 2, 2012 due to a reassessment of the likelihood of the study meeting its scientific objectives in light of data with the investigational drug obtained from another clinical study. The decision to terminate the trial was not based on any safety concerns.
Interventions
OTHERSaline
Saline infusion for 56 minutes
DRUGPF-02545920
PF-02545920 10 mg single dose
OTHERKetamine
Ketamine 0.23 mg/kg bolus over one min; and 0.58 mg/kg/hour maintenance for 56 minutes PF-02545920 10 mg tablet
OTHERPlacebo
Placebo tablet single dose
Sponsors
Pfizer
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
21 Years to 45 Years
Healthy volunteers
Yes
Inclusion criteria
* Healthy male and/or female subjects between the ages of 21 and 45 years, inclusive. Body Mass Index (BMI) of 17.5 to 30.5 kg/m2; and a total body weight \>50 kg (110 lbs). (Healthy is defined as no clinically relevant abnormalities identified by a detailed medical history, full physical examination, including blood pressure and pulse rate measurement, 12 lead ECG and clinical laboratory tests). * Right handed as determined by handedness questionnaire. * Able to read and write English as a primary language.
Exclusion criteria
* Female subjects who are pregnant or breastfeeding. * Any evidence of significant psychosis-like symptoms. * Known sensitivity to ketamine.
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Lateral prefrontal cortex activation as measured by functional MRI (fMRI) BOLD imaging during causal learning and working memory tasks | Day 1 of each treatment period |
Secondary
| Measure | Time frame |
|---|---|
| Lateral prefrontal cortex activation during causal learning and working memory tasks as measured by arterial spin labelling imaging | Day 1 of each treatment period |
| Causal learning task prediction error score for stimulus/outcome associations across 3 stages of learning and expectancy violation | Day 1 of each treatment period |
| N-back working memory task number correct | Day 1 of each treatment period |
| Positive and Negative Syndrome Scale (PANSS) positive and negative subscale total score | Day 1 of each treatment period |
| Clinician administered dissociative states scale (CADSS) total score | Day 1 of each treatment period |
Countries
United States
Outcome results
None listed