The safety of extended-release drug formulations for the treatment of ADHD

ABSTRACT

Introduction: Attention-deficit/hyperactivity disorder (ADHD) is a complex neurobehavioral disorder affecting millions of patients worldwide. Effective treatments have been available for more than 60 years in the form of immediate-release (IR) stimulants However, stimulants have a high risk for abuse and are associated with adverse effects Including elevated blood pressure and heart rate, insomnia and decreased appetite. IR formulations also require multiple daily dosing. The search for improved safety, tolerability and convenience has led to the development of multiple extended-release (ER) stimulant and non-stimulant formulations.

Areas covered: Adverse effects of (ER) products including amphetamine, methylphenidate, clonidine and guanfacine will be reviewed and their significance discussed.

Expert opinion: Limitations of currently marketed medications have led to the search for drugs with efficacy comparable to ER stimulants and a more favorable adverse event profile. Several are in development, but their potential utility is not yet known. Current research is also focused on finding specific genetic defects in patients with ADHD. Exciting progress has been made with the identification of mGluR receptor defects in some patients. However because of the heterogeneity of the disorder, effective targeted treatments for the majority of patients with ADHD does not appear likely in the near future.

KEYWORDS:

• ADHD
• attention-deficit/hyperactivity disorder
• amphetamine
• clonidine
• methylphenidate
• guanfacine

Article highlights

• Multiple ER formulations are marketed in the U.S. for the treatment of ADHD

• Although ER stimulants carry warnings for cardiovascular events such as sudden death in patients with structural cardiac abnormalities or other serious heart problems, the majority of patients treated with the medications do not develop clinically significant AEs

• The stimulants and non-stimulants have different AE profiles, and these should be considered when developing a treatment plan

• A switch to another ER product should be considered in patients who have tolerability issues with one medication

• GXR and CLON-XR may safely be used adjunctively with stimulants to improve ADHD symptoms

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Declaration of interest

A. Childress has acted as a consultant and speaker and has received research support from Shire, Novartis, Pfizer and Tris;, has acted as a consultant and/or served on an advisory board and received research support from NextWave, Neurovance, Neos, Noven, Akili, Rhodes, Purdue, Sunovion and Ironshore; has received research support from Lilly USA, LLC, Ortho-McNeil Janssen, Johnson & Johnson, Theravance, Forest, Ostuka, and Pearson. The author has no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Additional information

Funding

This paper was not funded.