A study protocol for the N-ICE trial: A randomised double-blind placebo-controlled study of the safety and efficacy of N-acetyl-cysteine (NAC) as a pharmacotherapy for methamphetamine ("ice") dependence.

Abstract

BACKGROUND:

There are currently no approved pharmacotherapies for managing methamphetamine dependence. N-acetylcysteine (NAC) has been found to reduce the craving for methamphetamine and other drugs, but its effect on methamphetamine use and other clinically related endpoints are uncertain. The N-ICE trial is evaluating the safety and efficacy of NAC as a take-home pharmacotherapy for methamphetamine dependence.

METHODS/DESIGN:

This is a two-arm parallel double-blind placebo-controlled three-site randomised trial (ratio 1:1) using permuted block randomisation, with variable block sizes. It is stratified by site, sex and whether the methamphetamine is injected or not. Participants (N = 180; 60 per site) need to be dependent on methamphetamine, interested in reducing their methamphetamine use and not currently receiving treatment for substance use disorders. The trial is being conducted in outpatient settings in Melbourne, Geelong and Wollongong, Australia. Participants will receive either 2400 mg oral NAC or a matched placebo, delivered as a take-home medication for 12 weeks. Two 600 mg capsules are self-administered in the morning and two more in the evening. Adherence is being monitored using eCAP™ medication bottle lids, which record the date and time of each occasion the bottle is opened. The primary outcome is methamphetamine use during the 12-week trial medication period, measured as (a) days of use, assessed using the timeline followback, and (b) methamphetamine-positive saliva tests, taken weekly. Secondary measures include weekly assessment of methamphetamine craving, severity of methamphetamine dependence, methamphetamine withdrawal symptoms and psychiatric symptoms (depression, suicidality, psychotic symptoms and hostility). Adverse events are monitored at each weekly assessment. Tolerability is assessed using the Treatment Satisfaction Questionnaire for Medication.

DISCUSSION:

The N-ICE trial is the first clinical trial to assess whether NAC can reduce methamphetamine use. This trial will improve our understanding of the potential utility of NAC in managing methamphetamine dependence and clinically related outcomes. If found to be effective, take-home NAC could be a potentially scalable and affordable pharmacotherapy option for treating methamphetamine dependence.

TRIAL REGISTRATION:

Australian and New Zealand Clinical Trials Registry, ACTRN12618000366257 . Registered on 29 May 2018.

• Authors: Rebecca McKetin, Olivia M Dean, Alyna Turner, Peter J Kelly, Brendan Quinn, Dan I Lubman, Paul Dietze, Gregory Carter, Peter Higgs, Amanda L Baker, Barbara Sinclair, David Reid, Victoria Manning, Nina Te Pas, Wenbin Liang, Tamsin Thomas, Ramez Bathish, Margaret Kent, Dayle Raftery, Shalini Arunogiri, Frank Cordaro, Harry Hill, Michael Berk
• Journal: Trials (Trials) Vol. 20 Issue 1 Pg. 325 (Jun 04 2019) ISSN: 1745-6215 [Electronic] England
• PMID: 31164169 (Publication Type: Clinical Trial Protocol, Journal Article)

Chemical References

• Central Nervous System Stimulants
• Methamphetamine
• Acetylcysteine

Topics

• Acetylcysteine (adverse effects, therapeutic use)
• Adolescent
• Adult
• Amphetamine-Related Disorders (diagnosis, drug therapy, physiopathology, psychology)
• Australia
• Central Nervous System Stimulants
• Clinical Trials, Phase II as Topic
• Craving (drug effects)
• Double-Blind Method
• Female
• Humans
• Male
• Methamphetamine
• Middle Aged
• Multicenter Studies as Topic
• Randomized Controlled Trials as Topic
• Substance Abuse, Intravenous (diagnosis, drug therapy, physiopathology, psychology)
• Time Factors
• Treatment Outcome
• Young Adult