Lytorin is the brand name. The name of the medicine it contains is called atorvastatin. It is indicated in the treatment of high cholesterol levels. Its side effects include GI upset, headache, muscle pain, joint pain, asthenia, insomnia, rash, flu-like syndrome, sinusitis, elevated liver (ALT & CPK) enzymes levels, sensory & mixed sensorimotor peripheral nerve disorders, tendon rupture, amnesia, myopathy, rhabdomyolysis (very serious muscle injury) with renal dysfunction.