COMT, dopamine and pain

     COMT polymorphisms have been linked to pain sensitivity. It has been suggested that a reduction in dopamine inactivation, such as is seen with the Met/Met genotype, results in higher levels of dopamine, leading to chronic stimulation of the dopamine receptors. This overstimulation may result in less endogenous opioids being produced that help to provide pain relief and euphoria. Therefore, Met/Met allele carriers can perceive a higher level of pain, while Val/Val carriers have the greatest resistance to pain. Interestingly, studies have shown that Met/Met allele carriers require less morphine to achieve pain relief, possibly due to the increase in μ-opioid receptors seen with this genotype, while Val/Val allele carriers require the most medication for pain management. COMT also has been shown to have an effect on L-DOPA therapy in Parkinson’s disease treatment. Commonly COMT inhibitors, such as entacapone, are utilized in Parkinson’s treatment to augment and prolong L-DOPA treatment. COMT polymorphisms affect the bioavailability of these medications, yielding a heightened effect of entacapone in the Val/Val allele carriers as compared to Met/Met allele carriers.

DOPAMINE LEVELS

-Val/Val LOWER

-Val/Met AVERAGE

-Met/Met HIGHER

 

PAIN RESPONSE

-Val/Val MORE TOLERANCE

-Val/Met AVERAGE

-Met/Met MORE ACUTE

 

PAIN MED NEED

-Val/Val POSSIBLE HIGHER DOSE

-Val/Met AVERAGE

-Met/Met PROBABLY