In clinical studies with COMTAN, with more than 1400 people with Parkinson's disease (PD), the most commonly reported side effects were unwanted or uncontrolled movements, nausea, urine discoloration, diarrhea, and abdominal pain. In response to some of these side effects, your doctor may advise you to reduce your dosage of levodopa.

Some of the more serious side effects that have been reported with COMTAN include low blood pressure, diarrhea, hallucinations, and unwanted or uncontrollable movements.

If you take nonselective MOA inhibitors (eg, phenelzine, tranylcypromine) you should not take COMTAN. COMTAN should not be taken with selegiline at doses higher than 10mg/day. If you are taking COMTAN you should not take Stalevo(carbidopa/levodopa).

If you are taking any drugs that are broken down by COMT, (eg, isoproterenol, epinephrine) your doctor will want to use COMTAN with caution. COMTAN should not be taken together with Stalevo.

If you have any liver problems your doctor will want to use COMTAN with caution, as your condition can affect the way your body breaks down COMTAN.

COMTAN is only available by prescription. Use as directed by your doctor- do not abruptly stop taking or reduce the amount of carbidopa/levodopa therapy and COMTAN therapy you take.

The Prescribing Information will explain how the drug will act in your body, possible side effects, drug interactions, and precautions for certain patients. For full prescribing information please Click Here