06. Stimulant Use Disorders

Overview

The two most common stimulants used in the US are cocaine and methamphetamines. Stimulants are more widely used than any other substance in the US except for cannabis. Cocaine is derived from the leaves of the coca bush and has a base and salt form. The base form is smoked, while the salt is usually used intravenously or intranasally. There are also more than a dozen synthetic stimulants that are available either by prescription or over the counter.

Mechanism of action

  • Stimulants all act to increase dopamine and norepinephrine levels, activating the central and peripheral nervous systems. 
  • Cocaine decreases reuptake of neurotransmitters, while amphetamines trigger release of neurotransmitters.

Pharmacokinetics

Smoked stimulants onset of action is within minutes, while intranasal and oral stimulants have an onset within 30 to 45 minutes. Stimulants are largely metabolized by the liver, and eliminated in the urine. Amphetamines are weak bases, so acidification of the urine or GI tract increases their elimination.

Stimulant Intoxication and Withdrawal

Stimulant intoxication

Stimulants produce increased energy, euphoria, and alertness. There is also a decrease in need for sleep and appetite. The duration and intensity of these effects depend on the potency, dose, and route of the specific substance ingested. At high doses, stimulants can cause anxiety, irritability, paranoia, impaired judgment, panic attacks, and even psychotic symptoms resembling schizophrenia.

Stimulant withdrawal

The symptoms of withdrawal are psychological rather than physiological, and include depression, decreased pleasure, fatigue, poor concentration, increased appetite, and increased sleep.

Stimulant Use Disorder

  • Determine if patient has a substance use disorder using DSM-V criteria.
  • Ask about type of stimulants used, frequency, use history, attempts to cut down, periods of sobriety, past treatment, other substances used, psychiatric history, etc.
  • Check CURES or appropriate drug monitoring program database.
  • Assess goals, barriers to treatment, readiness for treatment.

Treatment

  • Contingency management: when something of value (such as a prize or gift card) is given to patients as a reward for a negative urine drug test for stimulants. There is the most evidence supporting this approach for treatment of stimulant use disorders.
  • Community reinforcement approaches in combination with contingency management lead to higher rates of abstinence in patients with stimulant use disorders.
  • Cognitive behavioral therapy involves psychotherapy that is aimed at changing a patient’s behaviors and thoughts.
  • Medications:
    • There are no FDA-approved medications for stimulant use disorder.
    • The evidence does not support use of anti-depressant medications for stimulant use disorder, though there is an improvement in mood-related outcomes. However, one randomized controlled trial did show reduction in methamphetamine use with mirtazapine.
    • Dopamine agonists, antipsychotics, anticonvulsants, topiramate, and psychostimulants have all been studied for management of stimulant use disorders, and the only group that have shown promising early evidence of benefit are psychostimulants, which include bupropion, dexamphetamine, methylphenidate, and modafinil.

Key Points

  • Stimulant use disorders are very common in the US and stimulant use is second only to cannabis use in prevalence.
  • There are no FDA-approved medications for stimulant use disorders.
  • The approach with the most evidence for management of stimulant use disorder is contingency management.

 

Heron A. The ASAM Essentials of Addiction Medicine 2019; 60-65, 337-351.