A 42-year-old female with type 2 diabetes mellitus (DM) has been prescribed simvastatin since her LDL cholesterol has not dropped below 150 mg/dL, despite good nutrition and exercise.

Question

A 42-year-old female with type 2 diabetes mellitus (DM) has been prescribed simvastatin since her LDL cholesterol has not dropped below 150 mg/dL, despite good nutrition and exercise. The client asks why she has to have additional blood work consisting of LFTs, CPK, and hCG (human chorionic gonadotropin—hormone test for pregnancy) before the physician will prescribe the drug.

·       Give the rationale (explain the reason) for the blood work consisting of LFTs, CPK, and hCG and how HMG-CoA reductase inhibitors (statin drugs) may affect those lab results.

·       What teaching should the nurse provide to this patient about birth control and why?

·       The client calls the office after getting her prescription filled. She states that the nurse told her to take the drug in the evening, but the information she received from the pharmacy says that it can be taken any time. How should the nurse respond and why?

·       The client also informs the nurse that she has developed some muscle pain. She thought it was from working in her garden, but the pain has not lessened in 3 days. Is this a concern, and how should the nurse respond?

·       Identify the lab results the nurse will be evaluating for statin drug effectiveness; include therapeutic range for each.

Answer 1

1. Statins may cause hepatotoxicity (monitor LFTs upon initiation of therapy and periodically while patient is taking medication, rhabdomyolysis or myopathy (obtain CPK in any patient with symptoms suggestive of myopathy (pain, tenderness, stiffness, cramping, weakness, or generalized fatigue), and is contraindicated in pregnancy (may cause congenital defects).
2. Adequate contraception is recommended if an HMG-CoA reductase inhibitor is required in females of reproductive potential. Females planning a pregnancy should discontinue the HMG-CoA reductase inhibitor 1 to 2 months prior to attempting to conceive. Simvastatin should be discontinued immediately if an unplanned pregnancy occurs during treatment.
3. Simvastatin will be most effective if taken at night because this is when cholesterol is made.
4. Discontinue use until symptoms can be evaluated; evaluate patient for conditions that may increase the risk for muscle symptoms (eg, hypothyroidism, reduced renal or hepatic function, rheumatologic disorders such as polymyalgia rheumatica, steroid myopathy, vitamin D deficiency, or primary muscle diseases). Upon resolution, resume the original or lower dose of simvastatin. If muscle symptoms recur, discontinue simvastatin use. After muscle symptom resolution, may then use a low dose of a different statin (usually pravastatin is better tolerated in patients with muscle pain); gradually increase if tolerated.
5. Fasting lipid profile should be rechecked 4 to 12 weeks after starting therapy and every 3 to 12 months thereafter.
6. LDL<100
7. TC <200
8. TG <150
9. HDL >40

Answer 2

1)Give the rationale (explain the reason) for the blood work consisting of LFTs, CPK, and hCG and how HMG-CoA reductase inhibitors (statin drugs) may affect those lab results.

Statins including simvastatin cause hepatotoxicity therefore LFTs are measured at baseline and if the patient presents any sign of hepatotoxicity LFTs are repeated. A more serious, but rare side effect of statin therapy is myopathy, which is defined as muscle pain, tenderness or weakness with CPK elevations of 10 times the upper limit of normal. Monitoring CPK at baseline and when a patient presents with myopathy is important. Lastly, hCG status provides the information about a patient's pregnancy status. Statins are teratogenic so if the patient gets pregnant while being this therapy, it can cause serious damage to the fetus.

2) What teaching should the nurse provide to this patient about birth control and why?

Statins are teratogenic so if the patient gets pregnant while being this therapy, it can cause serious damage to the fetus. This patient can not get pregnant while being on this therapy, she needs to take birth control while taking this medication. 

3) The client calls the office after getting her prescription filled. She states that the nurse told her to take the drug in the evening, but the information she received from the pharmacy says that it can be taken any time. How should the nurse respond and why?

Simvastatin is one of the short acting statin that needs to be taken at bedtime as most of the cholesterol production happens when we are sleeping. 

4) The client also informs the nurse that she has developed some muscle pain. She thought it was from working in her garden, but the pain has not lessened in 3 days. Is this a concern, and how should the nurse respond?

The nurse should check the patient's CPK as the patient is complaining of pain after starting statin. Simvastatin out of all the statin, has the highest risk for causing myopathy. If the statin is continued, the patient's myopathy can progress to rhabdomyolysis which can be life threatening. 

5) Identify the lab results the nurse will be evaluating for statin drug effectiveness; include therapeutic range for each.

Depending on the dose of simvastatin, measure the LDL reduction, HDL, Total cholesterol and triglycerides. For the safety, check LFTs and CPK.