Profile of Inhaled Levodopa and its Potential in the Treatment of Parkinson’s Disease: Evidence to Date
Citation: Patel, A. B., & Jimenez-Shahed, J. (2018). Profile of inhaled levodopa and its potential in the treatment of Parkinson’s disease: evidence to date. Neuropsychiatric disease and treatment, 14, 2955.
Levodopa has been the gold standard for the treatment of Parkinson’s disease since the 1960s. However, it has been associated with both short-term (e.g., nausea, hypotension, hallucinations) and long-term side effects (e.g., motor fluctuations and dyskinesias).
- Motor fluctuations: Motor symptoms experienced during On and Off times experienced by PD patients which correlate with higher and lower levodopa concentrations.
- Can become more disabling than primary motor symptoms of PD
- 50-60% of patients starting Levodopa will develop motor complications within 3-4 years
There are various factors that contribute to the lack of consistent dopamine stimulation when using Levodopa:
- Levodopa has a short half-life (the time period when the medication becomes significantly less effective; 0.7-1.4 hours) and time to maximum plasma concentration (15-60 minutes).
- Delayed gastric emptying, competition with other proteins in one’s diet for transport from the gut to the bloodstream and competition for transport across the blood-brain barrier.
- Desensitization within the receptors in the brain.
Several adjunctive medications (e.g. Dopamine agonists with longer half-lives, Injectable short-acting dopamine agonists, antidyskinetic agent) have therefore been used to address the motor complications from Levodopa use. This article reviewed the effectiveness and safety of a novel dry-powder aerosol self-administered inhaled levodopa formulation (CVT301) for use in treating Off episodes of PD. Click here to the read full article.