BioNTech/Pfizer-Vaccine, Statin Therapy and Self Limiting Rhabdomyolysis

In mid July 2021 an 80-year-old woman received her second COVID-19 immunization with the BioNTech/Pfizer-vaccine (Comirnaty©). After 24 h she developed severe myalgia in her thighs (8/10 NRS) followed by a progressive muscle weakness. Ten days later, she presented herself to our emergency room with a proximal tetraparesis without sensory deficits. She had no fever and reported no relevant trauma or toxic exposures. She complained of general malaise and had painful thigh and deltoid muscles on palpation. She was neither able to walk nor to rise out of bed without assistance but could lift her head and showed symmetrical abdominal contractions and no scapula alata. Handgrip, speech, swallowing and ocular motor functions remained intact throughout. Her lab results revealed elevated serum Creatine Kinase (CK) (9.603 U/L, ref. <195 U/L) and myoglobin (11.162 μg/L, ref. 25 μg/L to 58 μg/L) levels while TSH, fT4 and CRP were unremarkable. She had no hyperkalemia (4.0 mmol/L) taking hydrochlorothiazide (25 mg) on a regular basis. To avoid further muscle damage we halted her long running statin therapy (80 mg simvastatin) and ensured adequate volume substitution. She developed no signs of acute kidney injury. Within the next seven days her deficits and lab results progressively improved and finally returned to normal (Figure 1). We discharged her seven days later after making a full recovery apart from minor residual muscle pain. In a follow-up over the telephone four weeks later, she indicated no lasting symptoms or deficits.