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.