Listen to the article
Home |
For many years, treatment has focused on levodopa. This drug, when taken by mouth, is changed within the body to form the chemical substance – dopamine - that is lacking in the brains of patients with Parkinson’s disease. Although highly effective in controlling the symptoms of Parkinson’s, the response to levodopa changes over time in many people. Also side-effects can increase with levo-dopa dose and time.
These changes begin as an ‘end-of-dose wearing off’ with a return of tremor and slow movement as the blood levels of levodopa fall. To combat this, the daily doses of levodopa are usually divided – but the total daily dose stays the same.
Blood concentrations of levodopa affect symptom control
However, as the disease progresses, predictable ‘end-of-dose wearing off’ is replaced by sudden and unpredictable fluctuations. This is known as the ‘on-off’ phenomenon. ‘On’ means the person is able to move, and ‘off’ means that they cannot. People taking levodopa may develop dyskinesias – jerky, uncontrollable movements – during the ‘on-off’ states.
Other drugs are now available that help overcome the lack of dopamine in the brain. One group is known as dopamine agonists. These drugs produce fewer dyskinesias than levodopa therapy.
