New drug offers alternative Parkinson’s treatment

Has fewer side effects, can be used as monotherapy

A new drug offers patients with early Parkinson’s disease effective control of motor symptoms without the disabling side effects common in standard long-term treatment. Ropinirole, manufactured by SmithKline Beecham under the brand name Requip, is the first dopamine agonist to be indicated for use as monotherapy in the early stages of the disease as well as in later stages as adjunctive therapy with levodopa. Currently available dopamine agonists are indicated for use only in advanced Parkinson’s disease.

Researchers at the Medical College of Georgia, which administered the clinical trials for ropinirole, say the drug is important because Parkinson’s patients typically get worse over time and require more drugs. Ropinirole can delay the need for additional drugs while improving symptoms. Further studies will be done to see if newer dopamine agonists such as ropinirole can actually alter the course of the disease and delay its progression.

Alternative to levodopa therapy

Parkinson’s disease, which affects between 500,000 and 1 million Americans, is a chronic and progressive neurological disorder that causes uncontrollable tremors, rigidity of the muscles, and other severe motor impairments. The disease is believed to result from the death of nerve cells that normally produce dopamine, which plays an important role in motor control. Standard treatment for Parkinson’s disease involves dopamine replacement therapy with levodopa, which is effective initially but after long-term use causes disabling side effects such as twitching, jerking, hallucinations and fluctuations of motor response in many patients.

A 12-month, double-blind, placebo-controlled clinical trial of 147 patients showed that the treatment benefits of ropinirole lasted for the entire 12 months without the need for additional drugs and with sustained improvements in motor functioning. Dosages were individualized to each patient but ranged between 1 mg and 8 mg three times daily. The study found that 44% of patients received monotherapy with ropinirole for 12 months without the need for levodopa, compared with 22.4% who did not need levodopa in the placebo group. Also, 19% of patients required additional symptomatic therapy with levodopa at the end of the 12-month period, compared to 45.6% in the placebo group.

Fewer side effects noted

Patients in the clinical trial generally tolerated ropinirole well, with the most common side effects being expected ones such as nausea, dizziness, and drowsiness. About 7% of patients reported hallucinations.

There are no contraindications for the drug. It is currently under review at the U.S. Food and Drug Administration both as early monotherapy and as adjunctive treatment with levodopa.

[For additional information on ropinirole, contact SmithKline Beecham at (800) 366-8900, Ext. 5231.]