Cognitive skills worse/Could not think clearly; Started a new drug a week earlier (prior to starting the GOCOVRI) to help urination (Flomax) and it seemed like the GOCOVRI was working against that; not feeling 100%; never felt he reached full potential with the drug; Real vivid dreams; Feeling tired and slow; Slower speech; Wasn't sleeping well; wasn't sleeping very soundly; Woke up talking; Drowsiness/falling asleep at the wheel; Slow urination; This is a solicited report based on the information received by Pfizer from a contactable consumer.   A 63-years-old male patient received bnt162b2 (PFIZER-BIONTECH COVID-19 mRNA VACCINE), first vaccination dose via an unspecified route of administration in 2021 (Batch/Lot number was not reported) as SINGLE DOSE for covid-19 immunization. Medical history included Parkinson's disease, confusional state, dyskinesia. In patients with Parkinson's disease receiving levodopa-based therapy. Concomitant medications included mirabegron (MYRBETRIQ), (pramipexole dihydrochloride) MIRAPEX, (acetylsalicylic acid) BABY ASPIRIN and LEVODOPA. Concomitant products included an unspecified levodopa-based therapy. The patient previously took amantadine and experienced confusional state, tadalafil (CIALIS) and experienced inhibitory drug interaction. On or around 11Mar2021 (a week prior to the start of amantadine hydrochloride (GOCOVRI), the patient started Flomax (Batch/Lot number was not reported) to an unspecified date, at 0.4 mg for an unspecified indication. On 18Mar2021, the patient started treatment with GOCOVRI 137 MG at 137 mg, taken orally once day, at bedtime for dyskinesia. On 19Mar2021, the patient experienced slow urination and Drowsiness. It seemed like the GOCOVRI was working against the Flomax and it didn't seem as easy to go. On 25Mar2021, treatment with the product was increased to 274 mg 1x/day at bedtime. On 26Mar2021, the day after starting the 2 pills dose of GOCOVRI (274 mg), the patient felt tired and slow, further described as just a little fatigued and slower speech. Overall, he just did not feel as perky as he thought he should be. In addition, he had issues with sleeping, clarified as he was not sleeping very soundly, was rolling, tossing and turning, had real vivid dreams and woke up talking. On 05Apr2021, the patient's doctor subsequently reduced his dose back to 1 pill (137 mg) a day. As of 09Apr2021, treatment with GOCOVRI was ongoing, while the status of Flomax was not reported. The feeling tired, slow speech, drowsiness, not sleeping well, vivid dreams, waking up talking, slow urination and presumably the interaction between the GOCOVRI and Flomax had improved. On an unspecified date in 2021, after the start of GOCOVRI, the patient's cognitive skills worsened. It was also reported that the patient was drowsy in the morning and had urination trouble first thing in the am (morning) that got better throughout the day. As of 12Apr2021, treatment with GOCOVRI and the worsened cognitive skills were ongoing. The status of the Flomax was not reported. The outcome of all the events were reported as unknown. As of 21Apr2021, it was learned on an unspecified date in Apr2021, the patient discontinued Gocovri due to an unspecified SE (side effect). As of 30Apr2021, it was learned the patient had a history of off times. On an unspecified date(s) in Mar2021, right after he started taking 2 pills (274 mg) of Gocovri, the patient's cognitive skills worsened, clarified as he experienced drowsiness spells and could not think clearly. The patient did a lot of driving and was falling asleep at the wheel. Since the start of taking Gocovri, the patient felt he never got to 100%. He took Gocovri to balance out the carbidopa/levodopa and he had more balance but just never felt he reached full potential with Gocovri. When he was late with his medications he still experienced the off times. On 05Apr2021, the patient decreased his dose to 137 mg and on 15Apr2021, treatment with Gocovri was discontinued. A week ago (relative to 30Apr2021), treatment with Mirapex was also withdrawn. As of 30Apr2021, the status of Flomax was not reported. The cognitive skills, clarified as drowsiness spells and inability to think clearly improved. No additional information was provided or was requested.  No follow-up attempts are needed. Information about lot/batch number cannot be obtained.  Follow-up (05May2021): New information received by Pfizer from a contactable consumer (patient) included: action taken with GOCOVRI, serious event mental impairment and non serious event therapeutic product effect incomplete added.   The reporter' s assessment of the causal relationship of the event atrial fibrillation with the Pfizer suspect product was not provided at the time of this report. Since no determination has been received, the case is managed based on the company causality assessment.  No follow-up attempts are possible; information about lot/batch number cannot be obtained.; Sender's Comments: Based on known mechanism of action of the drugs, the event of  somnolence, sleep talking, abnormal dreams  is assessed as not related to   suspect product BNT162B2 , and more likely due to concomitant Gocovri. However, The reported event  of  Mental Impairement, Cognitive disorder ,Slow speech, poor-quality sleep and Fatigue is assessed as not related to suspect product BNT162B2 , and more likely due to underlying medical condition of Parkinsonism and the reported event of Inhibitory  drug interaction is assessed as unrelated to the suspected product BNT162B2. Therapeutic drug ineffective appears to be due to the co-suspect drug GOCOVRI. The impact of this report on the benefit-risk profile of the Pfizer product and on the conduct of the study is evaluated as part of Pfizer procedures for safety evaluation, including the review and analysis of aggregate data for adverse events. Any safety concern identified as part of this review, as well as any appropriate action in response, will be promptly notified to regulatory authorities, Ethics Committees, and Investigators, as appropriate.