Levodopa, or L-Dopa, is the cornerstone of conventional treatment for Parkinson's disease, particularly among the over 70s. Other drugs are usually tried first on younger sufferers because of the serious side effects that can be triggered by the drug

Nonetheless, L-dopa (generic: dopamine) comes with plenty of other problems that have been. Early side effects include nausea or vomiting, although practitioners say these pass fairly quickly as the body builds up tolerance to the drug. Others include hypotension (sudden lowering of blood pressure), aggravation of peptic ulcers, sweating attacks and discolouration of urine and sweat.

The more serious reactions (as if those were not serious enough) include the impairment of the motor skills, heart irregularities, mental changes including paranoia, sometimes leading to suicide. Convulsions have also occurred, albeit rarely.

The side effects admitted by the drug manufacturers in reference works such as the Physician's Desk Reference 1995 read more like a litany of common and not so common complaints, too numerous to mention here. Some, though, include nightmares, insomnia, headache, numbness, fatigue, euphoria, muscle twitching, diarrhea, constipation, skin rash, blurred vision, and weight gain or loss.

The biggest problem is trying to sort out the appropriate individual dose of the drug. Too little and the patient freezes, statue like; too much and the patient goes wild with uncontrollable movement.

And within 5-10 years, the drug stops working as patients lose their ability to convert L-Dopa.