The objective of this study is to test the safety and potential efficacy of ibudilast to
treat methamphetamine dependence. The study hypotheses are that ibudilast will reduce
methamphetamine use and increase treatment retention more than placebo among patients seeking
treatment for methamphetamine dependence. As HIV infection is a common complication of
methamphetamine dependence, half of the participants will be HIV positive and the study will
assess whether ibudilast also improves HIV related outcomes (e.g. medication adherence, CD4
count, risk behaviors).