# 41 - Amfetamines

# Amfetamines

Addictions and substance misuse
CHAPTER 4
There is a small developing evidence base for the potential of interventions based on 
neuromodulation such as transcranial magnetic stimulation (tMS) in SUD. This is an 
area of research in its early stages, without consensus on an appropriate cortical target 
or optimal frequency of TMS.15
An important area of consideration is the management of patients with SUD and 
suspected or verified attention deficit hyperactivity disorder (ADHD). As might be 
expected, ADHD is more common in patients with substance use disorder.16 There is 
limited guidance to support clinicians in making a definitive diagnosis of ADHD in this 
group of patients or to navigate the risk–benefit balance of commencing treatment with 
stimulants compared with second-­line non-­stimulant-­based alternatives.17,18
Cocaine
Cocaine is a naturally derived compound found in the coca plant. Aside from application as a topical anaesthetic, it is primarily used recreationally. Once extracted, cocaine’s 
properties are enhanced when processed into cocaine hydrochloride, a powdered form 
that is commonly insufflated (snorted). Removal of the hydrochloride creates a water-­
insoluble base form (freebase) known as ‘crack’ that can be smoked. Both forms of 
cocaine can be injected although as a freebase it must first be dissolved in an acid. An 
epidemiological study from 2023 suggests an increase in rates of crack injection in both 
England and Wales.19
Detoxification
Symptoms of withdrawal include depressed mood, agitation and insomnia. These are usually self-­limiting. It should be noted that given cocaine’s short half-­life and the binge nature 
of cocaine use, many patients essentially detoxify themselves regularly, with no pharmacological therapy. Symptomatic relief such as the short-­term use of hypnotics may be helpful 
in some, but these agents may become agents of dependence themselves for some patients.14
Substitution treatment
There is little evidence for substitution therapy for the treatment of cocaine misuse and 
it should not usually be prescribed.1,9,11
Amfetamines
Amfetamine-­type substances were first synthesised in the early 20th century initially 
having a wide range of applications. Currently, their clinical use is restricted to the 
treatment of ADHD and narcolepsy.20 Amfetamine as a salt, usually amfetamine sulphate, the cathinone mephedrone and the more potent, long-­acting methamphetamine 
are most commonly associated with significant misuse.
Within a recreational context, amfetamine sulphate is known as ‘speed’ and mephedrone as ‘drone’ or ‘meow meow’; names for methamphetamine include ‘meth’, ‘crystal’ 
or ‘tina’. These substances can be ingested as tablets or ‘pills’, insufflated as powders 
and, less commonly, injected or ‘slammed’. Methamphetamine, when in its crystalline 
form ‘ice’, can also be inhaled.