The influence of dopamine β-hydroxylase gene polymorphism rs1611115 on levodopa/carbidopa treatment for cocaine dependence: a preliminary study

Pharmacogenet Genomics. 2014 Jul;24(7):370-3. doi: 10.1097/FPC.0000000000000055.


Recent studies have suggested that heterogeneity in the level of dopamine activity and function might be useful for identifying a subgroup of cocaine-dependent patients responding better to dopamine-enhancement pharmacotherapy. Here we hypothesized that response to levodopa/carbidopa treatment would be greater in patients with genetically determined low levels of the dopamine metabolizing enzyme dopamine β-hydroxylase (DβH). Seventy-one cocaine-dependent patients who participated in a 12-week randomized double-blind placebo-controlled trial of levodopa/carbidopa were genotyped for the DβH gene (DBH) polymorphism rs1611115. Our results showed that for patients with the low DβH activity genotypes (CT/TT) who received levodopa, the odds of having cocaine-positive urine decreased significantly over treatment compared with placebo-treated patients with the CT/TT genotypes (P=0.004). Individuals with the normal DβH activity genotype (CC) showed no differential response to levodopa. These preliminary results need to be confirmed in a larger sample focusing on the DBH polymorphism.

Publication types

  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adult
  • Carbidopa / pharmacology*
  • Cocaine-Related Disorders / genetics*
  • Dopamine beta-Hydroxylase / genetics*
  • Double-Blind Method
  • Female
  • Genotype
  • Humans
  • Levodopa / pharmacology*
  • Male
  • Middle Aged
  • Odds Ratio
  • Pharmacogenetics
  • Polymorphism, Genetic*
  • Treatment Outcome


  • Levodopa
  • Dopamine beta-Hydroxylase
  • Carbidopa