Pharmacotherapy

There are two main types of pharmacotherapies used in the treatment of ADHD: psychostimulants and non-stimulants. Table 40 lists some of the pharmacological treatments for ADHD. For ADHD as a single disorder, the first line pharmacotherapies are the psychostimulants lisdexamfetamine and methylphenidate [885, 915]. Despite robust findings regarding the effectiveness of these pharmaceuticals among people with ADHD alone, findings among people with co-occurring AOD use disorders have been less promising. While these medications have been associated with modest reductions in ADHD symptoms, few studies have found them to demonstrate superiority over placebos [916, 917]. Nonetheless, psychostimulants, in combination with psychotherapy, are safe, are associated with reductions in ADHD symptoms, and remain the first line recommendation for the treatment of ADHD among people with AOD use disorders [884, 916, 917]. Some trials also indicate that more meaningful reductions in ADHD symptoms among people with AOD use disorders may be achieved with higher doses of psychostimulants [884, 918]. Irrespective of dose, it is essential that a medical assessment be conducted prior to the prescription of psychostimulants to ensure that the person does not have cardiovascular or other conditions that may contraindicate psychostimulant prescription [919].

While there has been some concern regarding the use of psychostimulants among people with AOD use disorder due to their potential for misuse and diversion [920], it is important to note that this view is not supported by the evidence. Psychostimulant medications, particularly longer acting formulations such as lisdexamfetamine or extended-release methylphenidate, have low abuse potential [884, 921]. Nonetheless, it has been suggested that prescribers may wish to consider the use of non-stimulants if extra-medicinal use of psychostimulants is of great concern [916]. In view of the fact that non-stimulants are less efficacious than psychostimulants in treating ADHD, and in the absence of evidence of any misuse of long-acting stimulants in clinical trials, there is a need to balance the potential risk of misuse and diversion, against the risk of untreated or inadequately treated ADHD [922].

Atomoxetine, a non-stimulant noradrenaline reuptake inhibitor, is recommended for those who cannot tolerate, or do not respond to, lisdexamfetamine or methylphenidate [885]. As is the case with psychostimulants, it appears that atomoxetine may not be as effective among people with AOD use disorders compared to those with single disorder ADHD, but this body of research is small [916]. Close monitoring for signs of any depressive symptoms during the first few months of atomoxetine administration is recommended (including agitation, self-harm behaviours, and suicidal ideation) as there have been some reports of increased risk among children [919]. Preliminary research has also been conducted on the non-stimulants bupropion (norepinephrine reuptake inhibitor), guanfacine and clonidine (alpha 2- adrenoceptor agonists); but conclusions regarding their efficacy cannot be made at this time [884, 916].

Adapted from Zalauf et al. [892], Pérez de los Cobos et al. [886] and the Better Health Channel [923]. For a full list of generic brands available, see the Therapeutic Goods Administration website (https://www.tga.gov.au).