Carbidopa is used with another medicine called levodopa to treat the symptoms of Parkinson’s disease (stiffness, tremors, spasms, poor muscle control). Symptoms of Parkinson’s disease may be caused by low levels of a chemical called dopamine (DOE pa meen) in the brain.
Levodopa is converted to dopamine in the brain. Carbidopa helps prevent the breakdown of levodopa before it can reach the brain and take effect.
Carbidopa is only used in combination with levodopa. Carbidopa has no effect when used alone.
Carbidopa is also used with levodopa to treat muscle symptoms similar to Parkinson’s disease that are caused by certain drugs such as chlorpromazine (Thorazine), fluphenazine (Prolixin), perphenazine (Trilafon), and others.
worsening of tremors (uncontrolled shaking);
severe nausea, vomiting, or diarrhea;
confusion, hallucinations, unusual changes in mood or behavior;
depression or suicidal thoughts;
seizure (convulsions); or
severe nervous system reaction--very stiff (rigid) muscles, high fever, sweating, confusion, fast or uneven heartbeats, tremors, feeling like you might pass out.
Some people taking carbidopa with levodopa have fallen asleep during normal daytime activities such as working, talking, eating, or driving. Tell your doctor if you have any problems with daytime sleepiness or drowsiness.
You may have increased sexual urges, unusual urges to gamble, or other intense urges while taking this medicine. Talk with your doctor if this occurs.
You may notice that your sweat, urine, or saliva appears dark in color, such as red, brown, or black. This is not a harmful side effect, but it may cause staining of your clothes or bed sheets.
Common side effects may include:
nausea, upset stomach;
sleep problems (insomnia), dreaming more than usual;
dry mouth, burning feeling in your tongue;
weight changes; or
abnormal liver function tests.
(oral tablet, compounding powder)