Citalopram is selective serotonin reuptake inhibitor (SSRI) likely favoured over other SSRIs in the treatment of cocaine dependence, mostly due to its relative lack of drug interactions, when compared to other SSRIs, combined with its low cost when compared to its S-enantiomer, escitalopram (due to patent protection). It was also used in the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) trial, for this very same reason, that is, because it lacks significant drug interactions besides that due to its serotonergic mechanism of action. Although it is more dangerous in overdose than the other SSRIs and is the only one, aside from escitalopram, that is known to prolong the QT interval.[1]
It is worth noting, however, that a recent meta-analysis has found that neither citalopram, nor desipramine, show significant efficacy in the treatment of cocaine dependence.[2]