potassium was high; This is a spontaneous report received from contactable reporter(s) (Consumer or other non HCP) from medical information team. The reporter is the patient.  A 63 year-old male patient received bnt162b2 (BNT162B2), intramuscular, administered in arm left, administration date 09Apr2021 (Lot number: EP7533, Expiration Date: 31Jul2021) at the age of 63 years as dose 1, single and intramuscular, administered in arm left, administration date 06May2021 (Lot number: EW0153, Expiration Date: 31Jul2021) as dose 2, single for covid-19 immunisation. The patient's relevant medical history was not reported. Concomitant medication(s) included: LISINOPRIL taken for hypertension; AMLODIPINE + ATORVASTATIN taken for hypertension, blood cholesterol increased; FLONASE ALLERGY RELIEF. The following information was reported: BLOOD POTASSIUM INCREASED (non-serious) with onset 29Apr2021, outcome "unknown", described as "potassium was high". Relevant laboratory tests and procedures are available in the appropriate section.  Additional information: It was reported that caller states he had both doses of the Pfizer COVID-19 vaccine. Also had COVID and in December 2020 he received the antibody infusion. First dose was received on 09Apr2021, and second dose was received on 06May2021. Had blood work checked on 20May2021 because the month before that he did blood work, and the potassium was high so went back this month on 20May2021 and had it checked again and it was still high. Caller not sure if it is from the vaccine but he is reading that there two different kinds of potassium in it potassium chloride and monobasic potassium. He will be seeing his doctor on 03Jun2021 in regard to this issue. Caller states several months ago he had gotten a blood test that showed the high potassium level, that sent him to the ER, and on redraw it was fine, so it was a false positive. So, he thought maybe the same thing happened this time but it was redrawn and it is still high. Was wondering if this has been reported. It was reported that a review of the Prescribing Information for Pfizer COVID-19 Vaccine did not find information regarding increase in blood potassium levels. As the Prescribing Information does not include all adverse reactions that have been reported or that may occur, please consult with your doctor/healthcare provider about what you have experienced/are experiencing. Because your doctor/healthcare provider is most familiar with your medical condition, clinical history, how your treatment has been conducted and any relevant information to your specific case, your doctor/healthcare provider is in the best position to advise you about the appropriate action to take. Upon Follow up it was reported that he has been getting high potassium readings and had both the first and second doses. He received first dose 09Apr2021 and second dose 06 May 2021. He had high potassium reading and had repeated blood work 20May2021, and it is still high. Patient confirmed information above. He did not have an email. He stated his weight fluctuates between 195-200-205. He lost 12 pounds when he had COVID during December. In Dec 2020, he had the antibody infusion. No further details provided. He went to the ER when they told him it was high. He has had several surgeries there previously and although some people do not like to go there, he had not had any issues with them. He went in and they could not find paperwork and wanted them to see their doctor. He was not fully vaccinated at the time and felt they did not treat him well. If it was that high, he felt they should have gotten him on back and started treating him, but they did not. He confirmed that he was not admitted to the hospital. In May2021, his doctor said he needed to get it checked again. They did not say how high it was. He went back on 20May2021. He thinks it was better because they did not suggest he go to the emergency room this time. He takes Flonase because his nose been like this for a few years especially in spring and fall. That is how he knew he had the COVID. He was stuffy all the time. His nose never runs and when he had the COVID it did.  No follow-up attempts are possible. No further information is expected.