Methamphetamine abuse. Because patients who abuse methamphetamine are at high risk of developing psychosis, neurologic complications, and neuropsychological disorders, initiating treatment early in the course of their addiction is of paramount importance. Treatment of methamphetamine addiction is complicated by the fact that these patients have a high prevalence of comorbid psychiatric disorders, which clinicians need to keep in mind when selecting therapeutic interventions.
There are no FDA-approved agents for treating methamphetamine abuse.31 Several drugs have been tried with varying degrees of success, including bupropion, modafinil, and naltrexone. A study of modafinil found no clinically significant effects for treating methamphetamine abuse; however, only approximately one-half of participants in this study took modafinil as instructed.32 Certain selective serotonin reuptake inhibitors, including fluoxetine and paroxetine, have not been shown to be effective in treating these patients. Naltrexone may be a reasonable medication to consider because of the high prevalence of comorbid alcohol abuse among methamphetamine users.
Other treatments for methamphetamine addiction consist of behavioral interventions such as cognitive-behavioral therapy. Clinical experience has shown that the risk of relapse depends on how long the patient has been abstinent prior to entering a treatment program, the presence of attention and memory deficits, and findings of poor decision-making on neuropsychological tests.
The presence of cognitive abnormalities has been reported to impact methamphetamine abusers’ response to treatment.33 These findings suggest the need to develop approaches that might improve cognition in patients who are undergoing treatment for methamphetamine abuse. The monoaminergic agent modafinil and similar drugs need to be evaluated in large populations to increase the possibility of identifying characteristics of patients who might respond to cognitive enhancement.34
Methamphetamine-induced psychosis. First-generation antipsychotics, such as haloperidol or fluphenazine, need to be used sparingly in patients with methamphetamine-induced psychosis because of the risk of developing extrapyramidal symptoms (EPS) and because these patients are prone to develop motor complications as a result of methamphetamine abuse. Second-generation antipsychotics, such as risperidone and olanzapine, may be more appropriate because of the lower risks of EPS.35 The presence of high norepinephrine levels in some patients with recurrent methamphetamine psychosis suggests that drugs that block norepinephrine receptors, such as prazosin or propranolol, might be of therapeutic benefit if they are shown to be effective in controlled clinical trials.