Choreiform Movement / Dyskinesias
Carbidopa prescribing information notes: “Carbidopa … may cause or exacerbate pre-existing dyskinesia.”
The following videos are Parkinson’s disease patients with a choreiform movement disorder. The commentator wrongly states that L-dopa caused the problem. On an optimal diet, this represents a vitamin B6 relative nutritional deficiency. It responds in time by stopping the carbidopa or benserazide while continuing the L-dopa and giving adequate amounts of vitamin B6.
With the L-dopa induced dyskinesias stopping carbidopa or benserazide while continuing on L-dopa and given adequate amounts of vitamin B6 will control the problem.
The Patient Perspective:
Sinemet is a combination of L-dopa and carbidopa; 89 % of Parkinson patients take it.
Between 1960 and 1975 when only L-dopa (without carbidopa or benserazide) L-dopa dyskinesias were described as reversible.
After carbidopa became available in the United States in 1975 medical literature began to document irreversible dyskinesias. Most doctors today believe all dyskinesias are from L-dopa even prescribing information notes that carbidopa can induce dyskinesias, see carbidopa may cause dyskinesias link above. We have mastered getting rid of the most common type of dyskinesias, carbidopa-induced.
We still occasionally see patients with L-dopa induced dyskinesias. These are very easy to manage.
The Scientific Perspective:
Before 1976, an era with no carbidopa administration, irreversible dyskinesias were not reported. In 2014, the authors documented that irreversible dyskinesias are usually caused by carbidopa, not L-dopa. Managing these dyskinesias requires stopping carbidopa and administering adequate vitamin B6. If adequate B6 is not administered the dyskinesias may be perceived as permanent and irreversible.
Neuropsychiatric Disease and Treatment 2016:12 763–775
Irreversible dyskinesias associated with Parkinson’s disease care only became known in the medical literature after carbidopa was introduced in 1975.
Irreversible dyskinesias associated with Parkinson’s disease are known to be extremely difficult to control.
Depletion of vitamin B6 can induce an antihistamine effect. This occurs when the two vitamin B6 dependent enzymes HDC and AADC which are responsible for synthesis of histamine are compromised by vitamin B6 depletion. Medical literature notes, “Managing these dyskinesias requires stopping carbidopa and administering adequate B6. If adequate B6 is not administered the dyskinesias may be perceived as permanent and irreversible.” Antihistamine dyskinesias have been reported in the medical literature: