Nursing care
Statins: what to check before you give it
Written and reviewed by Dana Whitfield, RN, MSN · 4 min read · Updated September 2026
Short answer
Statins lower LDL cholesterol by blocking HMG-CoA reductase, the enzyme the liver uses to make cholesterol, and are first-line for cardiovascular risk reduction. Unexplained muscle pain on a statin is treated as rhabdomyolysis until a CK level says otherwise. Patients need to know to report it rather than wait it out.
Why this drug and not another
Statins inhibit HMG-CoA reductase, the rate-limiting enzyme in hepatic cholesterol synthesis. With less cholesterol made in the liver, LDL receptors upregulate and pull more LDL out of circulation, which is the main mechanism behind the drop in LDL cholesterol seen on treatment.
They are first-line for both primary and secondary prevention of atherosclerotic cardiovascular disease because the LDL reduction is consistent and the outcome data behind it is extensive. Atorvastatin and rosuvastatin are considered high-intensity options, simvastatin and pravastatin lower-to-moderate intensity, and the choice between them depends on the patient's calculated cardiovascular risk and renal function rather than being interchangeable.
Administration and timing
Cholesterol synthesis in the liver peaks overnight, so statins with a shorter half-life, simvastatin and lovastatin among them, are typically dosed in the evening for best effect. Atorvastatin and rosuvastatin have longer half-lives and can be taken at any consistent time of day.
Statins can be taken with or without food, though grapefruit juice should be avoided with simvastatin and, to a lesser extent, atorvastatin, since it inhibits the enzyme that metabolises them and can raise drug levels significantly. Consistency matters more than the specific hour: the same time each day supports steady drug levels and makes adherence easier to track.
Monitoring parameters
A baseline liver function panel and lipid panel are drawn before starting, with the lipid panel repeated at 4 to 12 weeks to assess response and again periodically once the dose is stable. Routine liver enzyme monitoring after the baseline is no longer required for every patient, but should be checked if the patient develops symptoms suggestive of hepatotoxicity, such as jaundice or dark urine.
Creatine kinase, CK, is not checked routinely in an asymptomatic patient, but is drawn promptly if the patient reports unexplained muscle pain, tenderness, or weakness. A CK several times the upper limit of normal, particularly with dark or cola-coloured urine, points to rhabdomyolysis and the statin is held pending results and further workup.
Adverse effects to report
Myalgia is the adverse effect nurses hear about most, and the teaching point is unambiguous: unexplained muscle pain, tenderness, or weakness on a statin is treated as rhabdomyolysis until the CK proves otherwise. Waiting to see if it resolves on its own is not the right call, because rhabdomyolysis can progress to acute kidney injury from myoglobin released into circulation.
Less common but reportable effects include signs of liver injury, such as jaundice, dark urine, or right upper quadrant pain, and new-onset confusion or memory changes, which have been reported with statin use though the causal link remains debated. Elevated blood glucose and a small increase in new-onset diabetes risk have also been observed, which is worth mentioning if the patient has other diabetes risk factors.
Contraindications and cautions
Statins are contraindicated in active liver disease and in pregnancy, since cholesterol is essential to fetal development and statins are teratogenic in animal studies; patients of childbearing potential need reliable contraception while on therapy. They are used cautiously in patients with a history of significant alcohol use or existing hepatic impairment.
Combining a statin with fibrates, particularly gemfibrozil, or with strong CYP3A4 inhibitors raises the risk of myopathy and rhabdomyolysis substantially, so the drug interaction check matters as much as the dose itself. Renal impairment can also change dosing limits for some statins, so a current creatinine or eGFR should be part of the picture before starting or adjusting therapy.
Teaching points the exam tests
The exam-favourite pairing is muscle pain plus statins equals check CK, don't wait. Make sure the patient can repeat back that unexplained muscle pain, weakness, or dark urine means calling the prescriber promptly rather than assuming it will pass.
Reinforce grapefruit juice avoidance with simvastatin, the need for reliable contraception in patients who could become pregnant, and that statins treat a chronic risk factor rather than a symptom, so they should not be stopped just because the patient feels well. Lifestyle measures, diet and exercise, remain part of the plan alongside the medication, not instead of it.
The next step on this is the same as on everything else here: answer questions and read the rationales. Our cardiovascular practice questions are the closest set to what this page covers.
Common questions
Why are some statins taken at night?
Cholesterol synthesis in the liver peaks overnight, so short-half-life statins like simvastatin work best when dosed in the evening. Longer-acting statins, such as atorvastatin and rosuvastatin, can be taken at any consistent time of day.
What muscle symptoms on a statin need reporting?
Any unexplained muscle pain, tenderness, or weakness should be reported and worked up with a CK level, treated as possible rhabdomyolysis until that result comes back normal. Dark or cola-coloured urine alongside muscle pain is a stronger warning sign and warrants prompt evaluation.
Can statins be taken with grapefruit juice?
Grapefruit juice should be avoided with simvastatin and used cautiously with atorvastatin, since it inhibits the enzyme that metabolises these drugs and can raise blood levels. Rosuvastatin and pravastatin are less affected by this interaction.
Why are statins contraindicated in pregnancy?
Cholesterol is essential for fetal development, and statins have shown teratogenic effects in animal studies, so they are avoided in pregnancy. Patients of childbearing potential on a statin need reliable contraception while taking it.
Is routine liver monitoring needed on a statin?
A baseline liver panel is drawn before starting, but routine ongoing liver enzyme checks are no longer required for asymptomatic patients. Liver function is rechecked if the patient develops symptoms such as jaundice, dark urine, or unexplained fatigue.
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