Effects of tramadol on synovial fluid concentrations of substance P and interleukin-6 in patients with knee osteoarthritis: comparison with paracetamol

What Was Tested

The paper reports a study of Substance P, published as a randomized controlled trial.

The aim of this double-blind, randomised study in patients with knee OA was to compare their effects on synovial fluid concentrations of interleukin (IL)-6 and substance P (SP).

Why It Was Studied

Both the analgesic drugs tramadol and paracetamol are widely used for the symptomatic therapy of osteoarthritis (OA).

Moreover, the researchers evaluated plasma and synovial fluid concentrations of tramadol and its active metabolite (O-desmethyl-tramadol, M1) after oral treatment with this drug.

Who Took Part

The study group was 10 patients.

The age groups tagged for this paper are middle-aged adults and older adults, both men and women.

How the Study Was Run

The researchers set it up as a randomized and double-blind study.

The patients were allocated by chance, so the Substance P group and the comparison group should start out alike.

As a double-blind Substance P study, the assignments were hidden from both participants and investigators until the end.

The methods mention a period of 7 days.

What Was Measured

Moreover, the researchers evaluated plasma and synovial fluid concentrations of tramadol and its active metabolite (O-desmethyl-tramadol, M1) after oral treatment with this drug.

The subject headings attached to it are Acetaminophen, Interleukin-6, Osteoarthritis, Knee, Pain, Pain Measurement, Substance P and Synovial Fluid.

What This Means in Plain Language

The paper is a randomized and double-blind study of Substance P in 10 patients over 7 days.

With fewer than 40 people, it is a small study, so it is better read as an early signal for further research than as a settled answer.

The publication is from 2003 (International immunopharmacology), a journal based in Netherlands.

More context: the Substance P compound page, all human trials.