Comprehensive Nursing Pharmacology Q 16
Mandy, a patient, calls the clinic today because he is taking atorvastatin (Lipitor) to treat his high cholesterol and is having pain in both of his legs. You instruct him to:
A. Stop taking the drug and make an appointment to be seen next week.
B. Continue taking the drug and make an appointment to be seen next week.
C. Walk for at least 30 minutes and call if symptoms continue.
D. Stop taking the drug and come to the clinic to be seen today.
Correct Answer: D. Stop taking the drug and come to the clinic to be seen today.
Muscle aches, soreness, and weakness may be early signs of myopathy such as rhabdomyolysis associated with the HMG-CoA reductase class of antilipemic agents. This patient will need an immediate evaluation to rule out myopathy. The principal finding of the present study is that 7.5% (15/200) of atorvastatin-treated patients had myopathy and incidence of myopathy increases with increase in doses of atorvastatin. The most common complaint was pain which was reported by 93% of patients with myopathy.
Option A: There are several mechanisms postulated for statin-induced myopathy. Statin decreases the cholesterol content of the cell membrane so decreases its stability. It has been also hypothesized that it reduces the production of ubiquinone (coenzyme Q 10), which is a component of the respiratory chain in the inner mitochondrial membrane. This deficiency leads to abnormal energy metabolism and thus muscle weakness. Statins also prevent the formation of prenylated proteins which include Ras, Rac, and Rho GTP-binding proteins.
Option B: Additional doses may exacerbate the problem. There is not a single conscience for the management of statin-induced myopathy. All guidelines recommend determining serum CK levels on the onset of myopathy only not in asymptomatic patients. For a symptomatic rise in serum CK levels >10 times the upper limit of normal, immediate discontinuation of the drug is recommended. If CK levels are between 3 and 10 times the normal levels, there are different opinions among different guidelines stating suspension of statins till there is an improvement in symptoms.
Option C: Exercise will not reverse myopathy and delay diagnosis. Myopathy symptoms were found in a significant number of patients taking atorvastatin and the incidence of myopathy increases with an increase in the dose of atorvastatin. Further, though, the benefits of statins continue to outweigh their adverse effects. However, possible alternate options including statin switching, non-statin drugs, change in dosing regimens may also be considered to reduce the incidence of myopathy.