Apomorphine Injection Rapidly Improves Morning Akinesia in Parkinson's
Injected apomorphine rapidly improves morning akinesia in Parkinson's patients.
SAN DIEGO — For patients with Parkinson's disease, subcutaneous injections of apomorphine (Apokyn) work more rapidly than oral levodopa for overcoming morning akinesia, according to a study presented at the International Parkinson and Movement Disorder Society (MDS) 19th International Congress in San Diego.
Parkinson's disease patients with morning akinesia — an inability to start movement due to problems initiating motor programs in the central nervous system — may have to wait over 45 minutes before they can move if they experience delayed levodopa effects. Patients taking levodopa often experience fluctuating response times, which may be due to impaired gastric emptying. The researchers hypothesized that a non-oral medication delivery could bypass this issue and provide patients with a more predictable response.
The researchers performed a post-hoc analysis of the AM-IMPAKT trial, enrolling 127 participants initially. Of these, 97 completed the study and 88 are included in the final analysis.
The participants all reported experiencing morning akinesia and recorded their time to treatment response after taking levodopa in the morning for seven days. In order to meet inclusion criteria, each participant had to experience a >45 minute delay in medication effects for at least three of the seven days. They were then titrated to an optimal dose of apomorphine, administered via self-injection, each morning for the next seven days.
Within 20 minutes, 65% of the participants reported responding to apomorphine, compared with 1% of baseline levodopa measurements. Within 30 minutes, these numbers rose to 83% for apomorphine and 3% for levodopa. Within 45 minutes, the numbers were 94% for apomorphine and 30% for levodopa.
Apomorphine has already been approved to treat Parkinson's disease for over a decade, though it had not specifically been indicated to treat morning akinesia.
The researchers note that not all patients will be able to self-inject medication; in these cases, other forms of apomorphine, such as sublingual administration, could potentially be used.