Editing Simvastatin (section)

== Interactions ==

Simvastatin has important interactions with [[grapefruit]] juice and other drugs, including some that are commonly used for the treatment of cardiovascular disease.  These interactions are clinically important because increasing simvastatin serum levels above those normally provided by the maximum recommended dose increases the risk of muscle damage, including the otherwise rare and potentially fatal side effect of [[rhabdomyolysis]].<ref name=FDAJun2011/>

Consuming large amounts of grapefruit juice increases serum levels of simvastatin by up to three-fold, increasing the risk of side effects.<ref>{{cite journal | vauthors = Lilja JJ, Kivistö KT, Neuvonen PJ | title = Grapefruit juice-simvastatin interaction: effect on serum concentrations of simvastatin, simvastatin acid, and HMG-CoA reductase inhibitors | journal = Clinical Pharmacology and Therapeutics | volume = 64 | issue = 5 | pages = 477–83 | date = November 1998 | pmid = 9834039 | doi = 10.1016/S0009-9236(98)90130-8 | s2cid = 37013910 }}</ref><ref>{{cite journal | vauthors = Lilja JJ, Neuvonen M, Neuvonen PJ | title = Effects of regular consumption of grapefruit juice on the pharmacokinetics of simvastatin | journal = British Journal of Clinical Pharmacology | volume = 58 | issue = 1 | pages = 56–60 | date = July 2004 | pmid = 15206993 | pmc = 1884539 | doi = 10.1111/j.1365-2125.2004.02095.x }}</ref><ref>{{Cite web | url=http://www.nhs.uk/conditions/cholesterol-lowering-medicines-statins/pages/interactions---other-medicines.aspx | title=Cholesterol-lowering medicines, statins - Interactions | date=16 April 2012 | publisher=[[National Health Service (England)|NHS]] | access-date=25 September 2013 | url-status=live | archive-url=https://web.archive.org/web/20130928105646/http://www.nhs.uk/conditions/cholesterol-lowering-medicines-statins/pages/interactions---other-medicines.aspx | archive-date=28 September 2013 }}</ref><ref>{{cite journal | vauthors = Lilja JJ, Kivistö KT, Neuvonen PJ | title = Duration of effect of grapefruit juice on the pharmacokinetics of the CYP3A4 substrate simvastatin | journal = Clinical Pharmacology and Therapeutics | volume = 68 | issue = 4 | pages = 384–90 | date = October 2000 | pmid = 11061578 | doi = 10.1067/mcp.2000.110216 | s2cid = 29029956 }}</ref> The FDA recommends that people taking statins should avoid consuming more than a quart (946 ml) of grapefruit juice per day.<ref name=FDAJun2011>{{cite web |url=https://www.fda.gov/Drugs/DrugSafety/ucm256581.htm |title=FDA Drug Safety Communication: New restrictions, contraindications, and dose limitations for Zocor (simvastatin) to reduce the risk of muscle injury |url-status=dead |archive-url=https://web.archive.org/web/20110611062703/https://www.fda.gov/Drugs/DrugSafety/ucm256581.htm |archive-date=11 June 2011 |publisher=U.S. [[Food and Drug Administration]] (FDA)|date=8 June 2011 }}</ref>

Simvastatin also interacts with other drugs, including some used to treat cardiovascular problems.  It should not be taken by people who are also taking the antifungal drugs [[fluconazole]], [[itraconazole]], or [[posaconazole]]; the antibiotics [[erythromycin]], [[clarithromycin]], or [[telithromycin]]; HIV protease inhibitors; the antidepressant [[nefazodone]]; the cardiovascular drug [[gemfibrozil]]; the immunosuppressant [[ciclosporin]], or the endometriosis drug [[danazol]].  Reduced maximum doses of simvastatin apply for patients taking certain other drugs, including the cardiovascular drugs [[verapamil]], [[diltiazem]], [[amiodarone]], [[amlodipine]], and [[ranolazine]].<ref name=FDAJun2011 /><ref name="urlInformation on Simvastatin/Amiodarone">{{cite web |url=https://www.fda.gov/Drugs/DrugSafety/PostmarketDrugSafetyInformationforPatientsandProviders/ucm118869.htm |title=Information on Simvastatin/Amiodarone |publisher=U.S. [[Food and Drug Administration]] (FDA) |date=8 August 2008 |access-date=21 September 2008 |url-status=dead |archive-url=https://web.archive.org/web/20090607013919/https://www.fda.gov/Drugs/DrugSafety/PostmarketDrugSafetyInformationforPatientsandProviders/ucm118869.htm |archive-date=7 June 2009 }}</ref>