Antinociceptive effects of fluoxetine and paroxetine with their related actions on glycemia in mice.

OBJECTIVES: Clinical and experimental trials have demonstrated that some of selective serotonin reuptake inhibitors (SSRIs) have some suspicious effects on blood glucose levels in different directions. Especially fluoxetine and sertraline are studied in this point of view. These drugs are also used in treatment of depression and peripheral neuropathy in diabetic patients. Paroxetine and fluoxetine, members of this drug group, besides having antidepressant effects were shown to have antinociceptive effects in animals and humans. They can be used in the treatment of chronic pain as an adjuvant drug or alone. But less is known about their actions on pain in case of diabetes. The aim of this study is to investigate the antinociceptive effects of fluoxetine and paroxetine in diabetic and non-diabetic mice while monitoring their effects on blood glucose levels.

METHODS: Mice of either sex were randomly used in experiments. The antinociceptive effects of paroxetine and fluoxetine were evaluated using hot plate test both in diabetic and non-diabetic mice. The effects of these drugs on blood glucose levels were also evaluated in another group of mice both in diabetic and non-diabetic mice.

RESULTS: Fluoxetine and paroxetine showed significant antinociceptive effect at all doses and at all times tested in non-diabetic mice, but they could not successfully show this effect in diabetic mice. They also had controversial effects on blood glucose levels.

CONCLUSION: Although they showed increasing or decreasing effects on blood glucose levels in non-diabetic and diabetic mice, they showed antinociception on hot-plate test showing dissociation between blood glucose levels and analgesia.