Sustained release formulation of pramipexole (Mirapex, Boehringer Ingelheim) outperforms its immediate release alternative to treat sleep disturbances in advanced Parkinson’s patients, a new study suggests.
The research, “Comparison of nocturnal symptoms in advanced Parkinson’s disease patients with sleep disturbances: pramipexole sustained release versus immediate release formulations,” was published in Drug Design, Development and Therapy.
Sleep disturbances, which may include insomnia, nightmares, restless sleep and daytime sleepiness, are among Parkinson’s non-motor symptoms and may worsen as the disease progresses.
Parkinson’s is characerized by the loss of dopamine-producing neurons in an area of the brain called the substantia nigra, which leads to reduced levels of the neurotransmiter dopamine.
As dopamine deficiency may explain sleep disturbances in Parkinson’s patients, treatment with dopamine receptor agonists such as pramipexole is a common first-line strategy. These compounds have similar properties to dopamine and can fulfill some of dopamine’s functions in the brain.
Mirapex is available in both immediate release tablets taken three times daily, and in a once-daily sustained release tablet for continuous delivery.
Studies have shown that continuously delivering dopaminergic treatment, rather than intermittent short-acting regimens, provides more constant stimulation of dopaminergic receptors. This, in turn, could reduce the risk of motor complications and sleep disturbances.
Even though the two formulations have shown similar effectiveness in trials assessing motor and non-motor symptoms, studies did not assess its effects on Parkinson’s-related sleep problems.
Now, a team of Chinese researchers compared the benefits of pramipexole sustained release and immediate release to treat nocturnal symptoms of advanced Parkinson’s patients with sleep disturbances who participated in a Phase 3 clinical trial (NCT00466167). All analyzed patients experienced motor fluctuations while on stable levodopa treatment.
A total of 119 patients reported sleep problems at the beginning of the study – 59 of whom received pramipexole sustained release, and 60 who received the immediate release formulation.
Although both formulations improved nocturnal symptoms, at week 18 patients taking the sustained release formulation reported greater relief from sleep disturbances than those on the immediate release formulation. However, this difference was not statistically significant.
Also, patients on the sustained release formulation had a greater mean change in all categories of the Parkinson’s Disease Sleep Scale (a tool to measure sleep problems in Parkinson’s disease) in comparison with those receiving pramipexole immediate release.
The number of patients experiencing any adverse effect was similar between both formulations — 62.7% vs 70% in sustained release or immediate release, respectively.
“The current observations on the numerical difference between groups suggest that future prospectively designed research is necessary to confirm the effects of pramipexole [sustained release] for improved sleep,” researchers wrote.
These findings show that “[pramipexole sustained release] and [immediate release] are equally safe and well tolerated by patients with advanced [Parkinson’s],” they said.