Advances in dopamine receptor agonists for the treatment of Parkinson’s disease

ABSTRACT

Introduction: Dopamine agonists (DA) are a class of agents which directly stimulate dopamine receptors mimicking the endogenous neurotransmitter dopamine. At first used as adjunctive therapy in the advanced phases of the disease, over the years a significant role was found for DA monotherapy as a first approach in the initial stage of Parkinson’s disease (PD). Several reviews have already reported efficacy and safety of DA in PD and differences between DA and levodopa. Therefore the objective of this review is to gather recent updates in DA therapy. A thorough knowledge of recent literature evidences, would help clinician in the management of treatment with DA.

Areas covered: Our review investigates recent updates on DA therapy, the role of these compounds in controlling non-motor symptoms (NMS) as well as new formulations under clinical evaluation and newly emerged post-marketing safety considerations. A literature search has been performed using Medline and reviewing the bibliographies of selected articles.

Expert opinion: DA represents a very important option in the treatment of PD, even though there are still some criticisms and unmet needs. A better knowledge of dopamine receptors could lead to identification of new compounds able to better balance clinical efficacy and side effects.

KEYWORDS:

• Dopamine agonists
• extended release
• Parkinson’s disease
• dopamine agonist withdrawal syndrome
• heart failure
• impulse control disorder
• apomorphine
• rotigotine
• ropinirole
• pramipexole
• non-motor symptoms

Article highlights

• DA remain very useful compounds in the treatment of PD. The new once a day and the transdermal formulations of DA made the use of the agonists easier increasing compliance of patients and adherence to treatment.

• New formulations of DA are currently under investigation for the treatment of early morning akinesia, post prandial OFF, unpredictable OFF, which dramatically impact on patients’ quality of life.

• The long clinical experience with DA agonists has also arised new complications like DAWS and heart failure and better defined aspects of Dopamine Disregulation Syndrome

• It is crucial that DA would be properly used in order to optimize benefits and minimize both short-term and long-term adverse effects.

This box summarizes key points contained in the article.

Declaration of interest

F Stocchi has been a consultant to TEVA, Novartis, GlaxoSmithKline, Lundbeck, Merck Serono, Merck Sharp & Dohme, UCB Pharma, ChiesiPharma, IMPAX, Newron, Zambon, Cynapsus and Britannia. He has also received research funding from Novartis and GlaxoSmithKline as well as received honoraria for educational symposia and consultancy to GlaxoSmithKline. The authors have 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 is not funded.