Conditions: Osteoarthritis, Knee
Keywords: osteoarthritis pain paracetamol Blood-Oxygen-Level-Dependent functional magnetic resonance imaging
Allocation: RANDOMIZED | Intervention model: CROSSOVER
Enrollment: 31
Healthy volunteers: no

Brief summary:
Blood-Oxygen-Level-Dependent (BOLD) responses to painful mechanical stimulation of the OA knee following treatment with four consecutive doses (at 8 hour intervals) on giving sustained released paracetamol treatment or placebo will be compared. The fMRI and pain assessments will occur approximately 2-5 hours after taking the final dose.

Detailed description:
The objective of this study is to investigate if functional magnetic response imaging (fMRI) can detect the effects of a known pain medicine at over-the-counter doses in people with osteoarthritis (OA) of the knee. The fMRI is a harmless and painless technique that is used in the current study to collect images of brain activity to see if is changed when feeling pain. In this study, BOLD response to mechanical stimulation via pressure stimuli applied to the tibio-femoral joint and patello-femoral in participants with knee OA following four treatment doses of any of three treatment will be compared.

Arms:
arm 1: Two 665 mg sustained release paracetamol caplets administered orally with water. arm 2: Two placebo caplets administered orally with water.

Interventions: intervention 1: Paracetamol intervention 2: Placebo
Intervention descriptions: intervention 1: 665 mg sustained release paracetamol caplets intervention 2: Placebo caplets

Protocol document: