Myopathy / Rhabdomyolysis
Simvastatin, like other inhibitors of GM-CoA reductase, can cause Myopathy, which manifests itself in the form of muscle pain, soreness, or weakness and is accompanied by an increase in the activity of CKK (more than 10 times higher than the upper limit of the norm (VGN)). Myopathy can manifest itself in the form of rhabdomyolysis, sometimes accompanied by secondary acute renal failure due to myoglobinuria. In rare cases, a lethal outcome was observed. The risk of developing myopathy is increased by increasing the concentration in the blood plasma of substances that have an inhibitory effect on HMG-CoA reductase. Risk factors for myopathy development include elderly age (> 65 years), female gender, uncontrolled hypothyroidism and renal dysfunction.
As with other HMG-CoA reductase inhibitors, the risk of myopathy / rhabdomyolysis depends on the dose. In clinical studies (the median duration of follow-up was 4 years), the incidence of myopathy with doses of 20, 40 and 80 mg per day was 0.03%, 0.08%, and 0.61%, respectively. In these studies, patients were closely monitored, and a number of drugs that could interact with simvastatin were not used.
In a clinical study in which patients with a history of myocardial infarction took simvastatin at a dose of 80 mg per day (mean follow-up 6,7 years), the incidence of myopathy was approximately 1.0%, and in patients taking the drug at a dose of 20 mg per day, 0.02%. Approximately half the cases of myopathy were reported during the first year of treatment. The frequency of myopathy during each next year of treatment was approximately 0.1%.
In patients receiving simvastatin in a dose of 80 mg per day, the risk of developing myopathy is higher than when using other statins that cause a comparable decrease in LDL cholesterol. Consequently, simvastatin in a dose of 80 mg per day should be prescribed only patients with a high risk of cardiovascular complications in whom drug therapy at lower doses did not achieve a therapeutic effect, and the perceived benefit of treatment exceeds the possible risk. If to the patient, acceptmaturing simvastatin in a dose of 80 mg, treatment with another drug that can interact with simvastatin is required, then it is necessary to reduce the dose of simvastatin or to prescribe another statin that has less potential for drug interaction (see Contraindications and Dosage and Administration).
All patients who start therapy with the drug Simvastatin, as well as patients who need to increase the dose should be warned about the possibility of myopathy and are informed of the need to immediately seek medical attention in the event of any unexplained pain, muscle soreness or muscle weakness. Drug therapy Simvastatin should be immediately discontinued if myopathy is diagnosed or at least assumed. The presence of the above symptoms and / or more than 10-fold increase in CKK activity in comparison with IGN indicate the presence of myopathy.In most cases, after an immediate discontinuation of simvastatin, the symptoms of myopathy are resolved, and the activity of CK decreases. In patients starting to take simvastatin or switching to increasing the dose of the drug, it is advisable to periodically determine the activity of CKK, but there is no guarantee that such monitoring can prevent the development of myopathy.
Many of the patients who underwent rhabdomyolysis during simvastatin therapy had a complicated history, including renal dysfunction, usually as a result of diabetes mellitus. Such patients require more careful observation.
Therapy with simvastatin should be temporarily discontinued in patients a few days before performing large surgical interventions, as well as in the postoperative period.
The risk of developing myopathy / rhabdomyolysis increases with the simultaneous use of simvastatin with the following drugs:
Contraindications
Powerful inhibitors of isoenzyme CYP3A4: concomitant therapy with potent inhibitors of isoenzyme CYP3A4 in therapeutic doses (for example, itraconazole, ketoconazole, posaconazole, erythromycin, clarithromycin, HIV protease inhibitors, boceprevirov, telaprevir or nefazodone) is contraindicated.If treatment with itraconazole, ketoconazole, posaconazole, erythromycin, clarithromycin or telithromycin can not be avoided, the therapy with simvastatin should be interrupted for the period of their use (see the section "Contraindications" and "Interaction with other medicinal products"),
Gemfibrozil, ciclosporin or danazol: simultaneous use of these drugs with simvastatin is contraindicated (see the section "Contraindications and interaction with other medicinal products").
Other drugs
Other fibrates: in patients taking fibrates other than gemfibrozil (see the section "Contraindications") or fenofibrate, the dose of simvastatin should not exceed 10 mg per day. With the simultaneous use of simvastatin and fenofibrate, the risk of developing myopathy does not exceed the amount of risks in treatment with each drug individually. Assign fenofibrate In combination with simvastatin should be cautious, since both drugs can cause myopathy. The adherence of fibrates to simvastatin usually leads to a slight additional decrease in the concentration of LDL cholesterol, but allows a more pronounced decrease in TG concentration and an increase in the concentration of HDL cholesterol.In small short clinical trials in which both drugs were used under close observation, combined therapy with fibrates with simvastatin was not accompanied by the development of myopathy (see section "Interaction with other drugs").
Amiodaroy: in patients taking amiodarone, the dose of simvastatin should not exceed 20 mg per day (see the section "Interaction with other medicinal products").
Blocks of "slow" calcium channels
Verapamil or diltiazem: in patients taking verapamil or diltiazem, the dose of simvastatin should not exceed 20 mg per day (see the section "Interaction with other medicinal products").
Amlodipine: in patients taking amlodipine, the dose of simvastatin should not exceed 40 mg per day (see the section "Interaction with other medicinal products").
Moderate inhibitors of isoenzyme CYP3A4: while simultaneous use of drugs with moderate inhibitory activity against isoenzyme CYP3A4, and simvastatin, especially at higher doses, may increase the risk of developing myopathy.
Fusidic acid: in patients taking both fusidic acid and simvastatin, may increase the risk of myopathy (see the section "Interaction with other drugs"). When fusidic acid and simvastatin are used concomitantly, patients should be carefully monitored and there may be a break in the treatment with simvastatin.
Nicotinic acid (> 1 g / day): with simultaneous use of simvastatin and nicotinic acid in lipid-lowering doses (> 1 g / day), cases of development of myopathy / rhabdomyolysis have been described. In a continuing double-blind, randomized clinical trial in China, the UK and Scandinavia, an interim safety analysis performed by an independent committee showed that the incidence of myopathy in approximately 4,700 patients (UK / Scandinavia), receivedof the simvastatin 40 mg or ezetimibe / simvastatin 10/40 mg in combination with sustained release laropiprant / nicotinic acid at a dose of 40 mg / 2 g was comparable to the overall incidence of myopathy in all clinical trials of simvastatin 40 mg (0.08%).However, in about 3900 Chinese patients in the same group, the incidence of myopathy was higher than expected (approximately 0.9%). In the control group (placebo + simvastatin 40 mg or ezetimibe / simvastatin 10/40 mg), the risk of myopathy in 8600 patients of Chinese, British and Scandinavian nationalities was not increased. Given the higher incidence of myopathy in Chinese patients, caution should be exercised when taking simvastatin (especially at doses> 40 mg) in combination with nicotinic acid or preparations containing nicotine a new acid, in lipid-lowering doses (> 1 g / day) in representatives of a given nationality. Since the risk of developing myopathy depends on the dose, therefore, it is not advisable for patients of Chinese nationality to prescribe simvastatin in a dose of 80 mg in combination with nicotinic acid or preparations containing nicotinic acid, in lipid-lowering doses (> 1 g / day). There are no data on the increased risk of myopathy in combination with other representatives of the Mongoloid race (see "Interaction with Other Drugs").
Effects on the liver
In some adult patients who took simvastatin, there was a steady increase in the level of activity of "hepatic" enzymes (more than 3 times higher than UGN). With the termination or interruption of the prescription of the drug, the activity of "hepatic" transaminases usually returns gradually to the baseline level. Increased activity of "liver" transaminases was not associated with jaundice or other clinical symptoms. No hypersensitivity reactions were identified. Some of the above patients had abnormalities in the results of functional hepatic samples prior to commencement of treatment with simvastatin and / or abused alcohol.
Before beginning treatment, and then in accordance with clinical indications, all patients are recommended to conduct a study of liver function. Patients who are scheduled to increase the dose of simvastatin up to 80 mg per day should perform additional liver function tests before switching to the specified dosage, then 3 months after the start of its use and then regularly repeat (for example, every six months) throughout first year of treatment.Particular attention should be given to patients with increased serum transaminase activity. These patients need to repeat the test in the near future and subsequently conduct it regularly until the activity of serum transaminases is normalized. In cases when the activity of "hepatic" transaminases increases, especially with a stable excess of 3 times VGN, the drug should be discarded. The cause of increased activity of alanine aminotransferase (ALT) may be muscle damage, so the increase in activity of ALT and CK can indicate the development of myopathy (see section "Special instructions, Myopathy / Rhabdomyolysis ").
There were rare post-registration reports of fatal and non-fatal cases of liver failure in patients withg including statins, including simvastatin. If severe liver disease with clinical symptoms and / or hyperbilirubinemia or jaundice develops with simvastatin treatment, therapy should be discontinued immediately. If another cause of the development of this pathology has not been identified, reassignment of simvastatin is contraindicated.
In patients who abuse alcohol and / or patients with impaired liver function, the drug should be used with extreme caution. Active liver disease or unexplained increase in aminotransferase activity are contraindications to the appointment of simvastatin.
During the treatment with simvastatin, as in the case of treatment with other lipid-lowering drugs, a moderate (less than 3 times higher than UGN) increase in the activity of serum transaminases was observed. These changes appeared soon after the start of treatment, often were transient, were not accompanied by any symptoms and did not require interruption of treatment.
Ophthalmological examination
The data of modern long-term clinical studies do not contain information on the adverse effects of simvastatin on the lens of the human eye.
Use in children and adolescents aged 10-17 years
The safety and efficacy of simvastatin in children and adolescents aged 10-17 years with heterozygous familial hypercholesterolemia were evaluated in controlled clinical trials involving 10-17 year olds and 10-17 year olds not less than 1 year after menarche.In patients of childhood, who took simvastatin, the side effect profile was similar to that of patients taking placebo. The use of simvastatin at a dose> 40 mg per day has not been studied in patients of childhood and adolescence. In this study, there was no significant effect of taking simvastatin on the growth and sexual maturation of young men and girls, or any effect on the length of the menstrual cycle in girls. Girls should be consulted about proper methods of contraception during treatment with simvastatin (see "Contraindications", "Pregnancy and Breastfeeding"). The use of simvastatin has not been studied in children younger than 10 years and in girls 10-17 years before menarche.
Use in elderly patients
In patients over the age of 65 years, the effectiveness of simvastatin, evaluatethe level of decrease in the concentration of OXC and LDL cholesterol is the same as for in the population as a whole, a significant increase in the frequency of clinical orboratory side effects were not observed. However, in a clinical study of the use of simvastatin 80 mg / day in patients older than 65 years, there was an increased risk of developingmyopathy compared with patients younger than 65 years.