INTRODUCTION
Rhabdomyolysis refers to the breakdown of skeletal muscle cells with the
release of their intracellular constituents into circulation, such as
myoglobin, enzymes (creatine kinase, transaminases, lactate
dehydrogenase) and electrolytes (potassium, phosphate) [1-3]. Its
causes may be physical such as trauma/ crush injury, prolonged
immobilization, intense muscle activity (seizure, exertion, neuroleptic
malignant syndrome), burns, and electrocution. It can have non-physical
causes such as drugs, toxins, venoms, infections, genetic myopathies,
dyselectrolytemia, ischemia and more. These non-physical causes induce
muscle damage by direct sarcolemmic injury, ATP-depleting and other
metabolic mechanisms [2, 3]. Drugs like statins and colchicine cause
direct myotoxicity whereas cocaine and amphetamines cause
vasoconstrictive ischemia [4, 5]. Concurrent usage of statins with
other drugs like steroids, cyclosporine, gemfibrozil and CYP450
inhibitors in general, increases the risk of statin-induced
rhabdomyolysis. Of the many complications of rhabdomyolysis, pigment
(myoglobin)-induced acute kidney injury (AKI) is common, seen in up to
30% of cases, especially so when CK levels are more than 5000 IU/L
[2].
COVID-19 is a known infectious cause of rhabdomyolysis, however,
literature suggests that usually only severe COVID-19 leading to hypoxia
causes rhabdomyolysis due to energy supply-demand mismatch [1].
Often, other risk factors are concurrently present with severe COVID-19,
that may contribute to this, such as old age, diabetes, hypertension,
hypothyroidism, injury, inborn errors of metabolism, and use of myotoxic
drugs like statins, fluoroquinolones, macrolide antibiotics, HIV
protease inhibitors, antipsychotics, and chemotherapy agents [1, 6].
Notably, the SARS CoV-2 virus spike protein is known to cause host cell
mitochondrial dysfunction, leading to altered bioenergetics and cellular
breakdown in muscles [1]. Asymptomatic COVID-19-associated
rhabdomyolysis and AKI is a less reported occurrence [7]. This
article will discuss this rare scenario, focusing on underlying risk
factors.