Pharmacokinetic profile of talipexole in healthy volunteers is not altered when it is co-administered with Madopar (co-beneldopa)

The current status of pharmacotherapy for the treatment of Parkinson's disease: transition from single-target to multitarget therapy

Parkinson's disease (PD) is a neurodegenerative disorder characterized by degeneration of dopaminergic neurons. Motor features such as tremor, rigidity, bradykinesia and postural instability are common traits of PD. Current treatment options provide symptomatic relief to the condition but are unable to reverse disease progression. The conventional single-target therapeutic approach might not always induce the desired effect owing to the multifactorial nature of PD. Hence, multitarget strategies have been proposed to simultaneously target multiple proteins involved in the development of PD. Herein, we provide an overview of the pathogenesis of PD and the current pharmacotherapies. Furthermore, rationales and examples of multitarget approaches that have been tested in preclinical trials for the treatment of PD are also discussed.

Duration of drug action of dopamine D2 agonists in mice with 6-hydroxydopamine-induced lesions

Although 6-hydroxydopamine-induced (6-OHDA-induced) rats are a well-known Parkinson's disease model, the effects of dopamine D2 agonists in mice with 6-OHDA-induced lesions are not completely understood. We produced mice with 6-OHDA-induced lesions and measured their total locomotion counts following administration of several dopamine D2 agonists (pramipexole, ropinirole, cabergoline, rotigotine, apomorphine, talipexole, and quinelorane). Cabergoline showed the longest duration of drug action, which was in agreement with its long-lived anti-Parkinson effects in rats and humans. In contrast, pramipexole and ropinirole had notably short durations of drug action. We demonstrated that mice with 6-OHDA-induced lesions accompanied with significant lesions in the striatum may be reasonable models to predict the action duration of anti-Parkinson drug candidates in humans.

Pharmacokinetic interaction between fluoxetine and omeprazole in healthy male volunteers: a prospective pilot study

BACKGROUND

Fluoxetine is an inhibitor of the main metabolizing enzymes (cytochrome P450 [CYP] 2C19 and CYP3A4) of omeprazole and thus might influence that drug's pharmacokinetics. The changes in omeprazole's pharmacokinetics may have clinical significance concerning efficacy and tolerability of the treatment.

OBJECTIVE

The aim of this study was to assess the pharmacokinetic interaction of fluoxetine with omeprazole in healthy volunteers.

METHODS

The study enrolled healthy adult men and consisted of 2 periods. In the first period, all subjects received a single 40-mg dose of omeprazole. This was followed by an 8-day period during which fluoxetine monotherapy (60 mg/d) was administered as a single oral daily dose. At the end of those 8 days, the subjects were administered a 40-mg dose of omeprazole with a 60-mg dose of fluoxetine. Plasma concentrations of omeprazole were determined at 0.5, 1, 1.33, 1.66, 2, 2.5, 3, 4, 5, 6, 7, 8, 10, and 12 hour(s) after study drug administration. Omeprazole plasma concentrations were determined by a validated HPLC method. Pharmacokinetic parameters of omep-razole were calculated using noncompartmental analysis. Adverse events were assessed throughout the study duration.

RESULTS

Eighteen healthy male volunteers (mean [SD] age, 22.11 [2.52] years [range, 18-26 years]; body mass index, 23.34 [2.31] kg/m(2) [range, 19.1-27.1 kg/m(2)]) were enrolled and completed the study. In the 2 periods of treatment, the mean Cmax of omeprazole was 730.8 ng/mL (omeprazole monotherapy) and 1725.5 ng/mL (combination treatment with fluoxetine). The observed AUC0-∞ was 1453.3 and 5072.5 ng/mL/h and AUC0-t was 1465.0 and 5185.3 ng/mL/h, respectively. The Tmax was 1.30 and 1.63 hours and the elimination rate constant was 0.753 and 0.482 hr(-1). The t½ was 0.96 and 1.47 hours, whereas the mean residence time was 2.33 and 3.35 hours, respectively. Statistically significant differences were observed for all parameters between periods 1 and 2 (all, P < 0.001).

CONCLUSION

The data found in this prospective pilot study suggest a pharmacokinetic interaction between fluoxetine and omeprazole in these healthy volunteers, but its relevance has to be confirmed.