Progesterone Reduces Cocaine Use in Postpartum Women with a Cocaine Use Disorder: A Randomized,Double-Blind Study

Background: Progesterone modulates multiple brain functions implicated in the pathogenesis ofdrug addiction. During high endogenous progesterone states, women reduce use of cocaine. We sought to test whether progesterone replacement reduces cocaine use in postpartum women with a cocaine use disorder (CUD).

Methods: A 12-week, double-blind, parallel, randomized, placebo-controlled pilot trial with a 3-month post trial follow-up. 25 women within 12 weeks of deliverywere randomized to placeboand 25 to100 mgs of oral micronized progesterone, administered twice daily. Participants were recruited from obstetrical clinics. Randomization and allocation were performed by the study biostatistician. Attrition was 18% and the analysis included all50participants. Outcomes were self-reported days of cocaine use and positive urine toxicology assays for cocaine metabolites.

Findings: Participants randomized to placebo compared to progesterone had increased likelihood of cocaine use per week (RR=1·19; 95% confidence interval (CI)=1·05 to 1·36; p<0·01). At the three-month post trial visit the difference between groups was not significant (Likelihood RatioΧ² =5·16; P=·08). There were no group differences in rates of submission of a positive urine test. A post hoc analysis showed a higher rate of relapse for participants randomized to placebo (HR=4·71; 95% CI= 1·09 to 20·5). We did not observe groups differences in the rate of adverse events.

Interpretation: These preliminary findings support the promise of progesterone treatment in postpartum women with a CUD and could constitute a therapeutic break through.

Funding: US National Institute on Drug Abuse; Veterans Administration.