Ropinirole .25 mg Tablet, Film Coated, 30-count — NDC 72189-364-30 (Billing 72189-0364-30)

12.1Mechanism of Action Ropinirole is a non-ergoline dopamine agonist. The precise mechanism of action of ropinirole as a treatment for Parkinson’s disease is unknown, although it is thought to be related to its ability to stimulate dopamine D 2 receptors within the caudate-putamen in the brain. The precise mechanism of action of ropinirole as a treatment for RLS is unknown, although it is thought to be related to its ability to stimulate dopamine receptors.

12.2Pharmacodynamics Clinical experience with dopamine agonists, including ropinirole, suggests an association with impaired ability to regulate blood pressure resulting in orthostatic hypotension, especially during dose escalation. In some patients in clinical trials, blood pressure changes were associated with the emergence of orthostatic symptoms, bradycardia, and, in one case in a healthy volunteer, transient sinus arrest with syncope [see Warnings and Precautions ( 5.2, 5.3)] . The mechanism of orthostatic hypotension induced by ropinirole is presumed to be due to a D2-mediated blunting of the noradrenergic response to standing and subsequent decrease in peripheral vascular resistance.

Nausea is a common concomitant symptom of orthostatic signs and symptoms. At oral doses as low as 0.2 mg, ropinirole suppressed serum prolactin concentrations in healthy male volunteers. Ropinirole had no dose-related effect on electrocardiogram wave form and rhythm in young, healthy, male volunteers in the range of 0.01 to 2.5 mg.

Ropinirole had no dose- or exposure-related effect on mean QT intervals in healthy male and female volunteers titrated to doses up to 4 mg/day. The effect of ropinirole on QTc intervals at higher exposures achieved either due to drug interactions, hepatic impairment, or at higher doses has not been systematically evaluated.

12.3Pharmacokinetics Ropinirole displayed linear kinetics over the dosing range of 1 to 8 mg 3 times daily. Steady-state concentrations are expected to be achieved within 2 days of dosing. Accumulation upon multiple dosing is predictive from single dosing.

Absorption Ropinirole is rapidly absorbed after oral administration, reaching peak concentration in approximately 1 to 2 hours. In clinical trials, more than 88% of a radiolabeled dose was recovered in urine and the absolute bioavailability was 45% to 55%, indicating approximately 50% first-pass effect. Relative bioavailability from a tablet compared with an oral solution is 85%.

Food does not affect the extent of absorption of ropinirole, although its T max is increased by 2.5 hours and its C max is decreased by approximately 25% when the drug is taken with a high-fat meal. Distribution Ropinirole is widely distributed throughout the body, with an apparent volume of distribution of

7.5L/kg. It is up to 40% bound to plasma proteins and has a blood-to-plasma ratio of 1:1. Metabolism Ropinirole is extensively metabolized by the liver.

The major metabolic pathways are N-despropylation and hydroxylation to form the inactive N-despropyl metabolite and hydroxy metabolites. The N-despropyl metabolite is converted to carbamyl glucuronide, carboxylic acid, and N-despropyl hydroxy metabolites. The hydroxy metabolite of ropinirole is rapidly glucuronidated.

In vitro studies indicate that the major cytochrome P450 enzyme involved in the metabolism of ropinirole is CYP1A2, an enzyme known to be induced by smoking and omeprazole and inhibited by, for example, fluvoxamine, mexiletine, and the older fluoroquinolones such as ciprofloxacin and norfloxacin. Elimination The clearance of ropinirole after oral administration is 47 L/h and its elimination half-life is approximately 6 hours. Less than 10% of the administered dose is excreted as unchanged drug in urine.

N-despropyl ropinirole is the predominant metabolite found in urine (40%), followed by the carboxylic acid metabolite (10%) and the glucuronide of the hydroxy metabolite (10%). Specific Populations Because therapy with ropinirole hydrochlorid… [Excerpted — this section continues on DailyMed.]

14.1Parkinson’s Disease The effectiveness of ropinirole hydrochloride in the treatment of Parkinson’s disease was evaluated in a multinational drug development program consisting of 11 randomized, controlled trials. Four trials were conducted in patients with early Parkinson’s disease and no concomitant L-dopa and 7 trials were conducted in patients with advanced Parkinson’s disease with concomitant L-dopa. Three placebo-controlled trials provide evidence of effectiveness of ropinirole hydrochloride in the management of patients with Parkinson’s disease who were and were not receiving concomitant L-dopa.

Two of these 3 trials enrolled patients with early Parkinson’s disease (without L-dopa) and 1 enrolled patients receiving L-dopa. In these trials a variety of measures were used to assess the effects of treatment (e.g., Unified Parkinson’s Disease Rating Scale [UPDRS], Clinical Global Impression [CGI] scores, patient diaries recording time “on” and “off,” tolerability of L-dopa dose reductions). In both trials of patients with early Parkinson’s disease (without L-dopa), the motor component (Part III) of the UPDRS was the primary outcome assessment.

The UPDRS is a multi-item rating scale intended to evaluate mentation (Part I), activities of daily living (Part II), motor performance (Part III), and complications of therapy (Part IV). Part III of the UPDRS contains 14 items designed to assess the severity of the cardinal motor findings in patients with Parkinson’s disease (e.g., tremor, rigidity, bradykinesia, postural instability) scored for different body regions and has a maximum (worst) score of 108. In the trial of patients with advanced Parkinson’s disease (with L-dopa), both reduction in percent awake time spent “off” and the ability to reduce the daily use of L-dopa were assessed as a combined endpoint and individually.

Trials in Patients with Early Parkinson’s Disease (without L-dopa) Trial 1 was a 12-week multicenter trial in which 63 patients with idiopathic Parkinson’s disease receiving concomitant anti-Parkinson medication (but not L-dopa) were enrolled and 41 were randomized to ropinirole hydrochloride and 22 to placebo. Patients had a mean disease duration of approximately 2 years. Patients were eligible for enrollment if they presented with bradykinesia and at least tremor, rigidity, or postural instability.

In addition, they must have been classified as Hoehn & Yahr Stage I-IV. This scale, ranging from I = unilateral involvement with minimal impairment to V = confined to wheelchair or bed, is a standard instrument used for staging patients with Parkinson’s disease. The primary outcome measure in this trial was the proportion of patients experiencing a decrease (compared with baseline) of at least 30% in the UPDRS motor score.

Patients were titrated for up to 10 weeks, starting at 0.5 mg twice daily, with weekly increments of 0.5 mg twice daily to a maximum of 5 mg twice daily. Once patients reached their maximally tolerated dose (or 5 mg twice daily), they were maintained on that dose through 12 weeks. The mean dose achieved by patients at trial endpoint was 7.4 mg/day.

Mean baseline UPDRS motor score was 18.6 for patients treated with ropinirole hydrochloride and 19.9 for patients treated with placebo. At the end of 12 weeks, the percentage of responders was greater on ropinirole hydrochloride than on placebo and the difference was statistically significant (Table 6). Table 6.

Percent Responders for Unified Parkinson’s Disease Rating Scale Motor Score in Trial 1 (Intent-to-Treat Population) Responders Difference from Placebo Placebo 41% NA Ropinirole hydrochloride 71% 30% Trial 2 in patients with early Parkinson’s disease (without L-dopa) was a double-blind, randomized, placebo-controlled, 6-month trial. In this trial, 241 patients were enrolled and 116 were randomized to ropinirole hydrochloride and 125 to placebo. Patients were essentially similar to those in the trial described above; concomitant use of sel… [Excerpted — this section continues on DailyMed.]

13.1Carcinogenesis, Mutagenesis, Impairment of Fertility Carcinogenesis Two-year carcinogenicity studies of ropinirole were conducted in mice at oral doses of 0, 5, 15, and 50 mg/kg/day and in rats at oral doses of 0, 1.5, 15, and 50 mg/kg/day. In rats, there was an increase in testicular Leydig cell adenomas at all doses tested. The lowest dose tested (1.5 mg/kg/day) is less than the MRHD for Parkinson’s disease (24 mg/day) on a mg/m2 basis.

The endocrine mechanisms believed to be involved in the production of these tumors in rats are not considered relevant to humans. In mice, there was an increase in benign uterine endometrial polyps at a dose of 50 mg/kg/day. The highest dose not associated with this finding (15 mg/kg/day) is 3 times the MRHD on a mg/m2 basis.

Mutagenesis Ropinirole was not mutagenic or clastogenic in in vitro (Ames, chromosomal aberration in human lymphocytes, mouse lymphoma tk) assays, or in the in vivo mouse micronucleus test. Impairment of Fertility When administered to female rats prior to and during mating and throughout pregnancy, ropinirole caused disruption of implantation at oral doses of 20 mg/kg/day (8 times the MRHD on a mg/m 2 basis) or greater. This effect in rats is thought to be due to the prolactin-lowering effect of ropinirole.

In rat studies using a low oral dose (5 mg/kg) during the prolactin-dependent phase of early pregnancy (gestation days 0 to 8), ropinirole did not affect female fertility at oral doses up to 100 mg/kg/day (40 times the MRHD on a mg/m 2 basis). No effect on male fertility was observed in rats at oral doses up to 125 mg/kg/day (50 times the MRHD on a mg/m 2 basis).