Ciprofloxacin with Simvastatin Interaction Details

Brand Names Associated with Ciprofloxacin

Brand Names Associated with Simvastatin

Medical Content Editor Dr. Brian Staiger, PharmD
Last updated Nov 19, 2023

Interaction Effect

An increased risk of myopathy or rhabdomyolysis

Interaction Summary

Concomitant use of ciprofloxacin and simvastatin may result in myopathy or rhabdomyolysis. The mechanism of action is thought to be weak inhibition by ciprofloxacin of cytochrome P450 3A4-mediated simvastatin metabolism, substrate and competitive inhibition by simvastatin of p-glycoproteins and multiple drug resistance associated proteins efflux mechanism of ciprofloxacin. Monitor CK levels and discontinue use if CK levels show a marked increase, or if myopathy or rhabdomyolysis is diagnosed or suspected.

Severity

Major

Onset

Unspecified

Evidence

Probable

How To Manage Interaction

Concomitant use of ciprofloxacin and simvastatin may result in myopathy or rhabdomyolysis. If concurrent therapy is required, monitor the patient for signs and symptoms of myopathy or rhabdomyolysis (muscle pain, tenderness, or weakness). Monitor CK levels and discontinue use if CK levels show a marked increase, or if myopathy or rhabdomyolysis is diagnosed or suspected.

Mechanism Of Interaction

Inhibition by ciprofloxacin of simvastatin metabolism

Literature Reports

A) A 77-year-old woman, maintained on simvastatin 40 mg, was hospitalized due severe muscle weakness, generalized muscle aches, and dark discoloration of her urine after coadministration of 2 doses of ciprofloxacin with her usual regimen of simvastatin. Upon physical examination, she was apyrexial, blood pressure (BP) was 197/68 mmHg, pulse rate was 68 beats per min, her muscles were tender to touch, grade 3 power proximally, grade 4 power distally, and she was unable to stand up from a chair. Laboratory analysis revealed the following: decreased hemoglobin (10.2 g/dL), normal WBC (9.3 x 10(3)/mm(3)), normal platelet count (235 x 10(3)/mm(3)), elevated erythrocyte sedimentation rate (80 mm/hr), normal creatinine (121 micromol/L), elevated C-reactive protein (20 mg/L), elevated creatinine kinase greater than 10 times the ULN (29,980 units/L), normal bilirubin (7 micromol/L), normal alkaline phosphatase (78 units/L), elevated alanine transaminase (212 units/L) and urine dipstick showed 4 + blood. Results for serum electrolytes and thyroid function were within normal range; additionally, the autoimmune screening results were negative. After hospitalization, the simvastatin and ciprofloxacin were discontinued and the patient was treated with hydration, and high dose methylprednisolone for 3 days. On day 14, the creatinine kinase levels returned to normal range (166 units/L) and the muscle biopsy showed very few lymphocytes and was not suggestive of polymyositis, thus the diagnosis was determined to be statin induced rhabdomyolysis possibly due to the interaction with ciprofloxacin .

Ciprofloxacin Overview

• Ciprofloxacin is used to treat or prevent certain infections caused by bacteria such as pneumonia; gonorrhea (a sexually transmitted disease); typhoid fever (a serious infection that is common in developing countries); infectious diarrhea (infections that cause severe diarrhea); and infections of the skin, bone, joint, abdomen (stomach area), and prostate (male reproductive gland), Ciprofloxacin is also used to treat or prevent plague (a serious infection that may be spread on purpose as part of a bioterror attack) and inhalation anthrax (a serious infection that may be spread by anthrax germs in the air on purpose as part of a bioterror attack). Ciprofloxacin may also be used to treat bronchitis, sinus infections, or urinary tract infections but should not be used for bronchitis and sinus infections, or certain types of urinary tract infections if there are other treatment options. Ciprofloxacin extended-release (long-acting) tablets are used to treat kidney and urinary tract infections; however, some types of urinary tract infections should only be treated with ciprofloxacin extended release tablets if no other treatment options are available. Ciprofloxacin is in a class of antibiotics called fluoroquinolones. It works by killing bacteria that cause infections.

• Antibiotics such as ciprofloxacin will not work for colds, flu, or other viral infections. Using antibiotics when they are not needed increases your risk of getting an infection later that resists antibiotic treatment.

Simvastatin Overview

• Simvastatin is used together with diet, weight-loss, and exercise to reduce the risk of heart attack and stroke and to decrease the chance that heart surgery will be needed in people who have heart disease or who are at risk of developing heart disease. Simvastatin is also used to decrease the amount of fatty substances such as low-density lipoprotein (LDL) cholesterol (''bad cholesterol'') and triglycerides in the blood and to increase the amount of high-density lipoprotein (HDL) cholesterol (''good cholesterol'') in the blood. Simvastatin may also be used to decrease the amount of cholesterol and other fatty substances in the blood in children and teenagers 10 to 17 years of age who have familial heterozygous hypercholesterolemia (an inherited condition in which cholesterol cannot be removed from the body normally). Simvastatin is in a class of medications called HMG-CoA reductase inhibitors (statins). It works by slowing the production of cholesterol in the body to decrease the amount of cholesterol that may build up on the walls of the arteries and block blood flow to the heart, brain, and other parts of the body.

• Accumulation of cholesterol and fats along the walls of your arteries (a process known as atherosclerosis) decreases blood flow and, therefore, the oxygen supply to your heart, brain, and other parts of your body. Lowering your blood level of cholesterol and fats with simvastatin has been shown to prevent heart disease, angina (chest pain), strokes, and heart attacks.

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Definitions

Severity Categories

Contraindicated

These drugs, generally, should not be used together simultaneously due to the high risk of severe adverse effects. Combining these medications can lead to dangerous health outcomes and should be strictly avoided unless otherwise instructed by your provider.

Major

This interaction could result in very serious and potentially life-threatening consequences. If you are taking this drug combination, it is very important to be under close medical supervision to minimize severe side effects and ensure your safety. It may be necessary to change a medication or dosage to prevent harm.

Moderate

This interaction has the potential to worsen your medical condition or alter the effectiveness of your treatment. It's important that you are monitored closely and you potentially may need to make adjustments in your treatment plan or drug dosage to maintain optimal health.

Minor

While this interaction is unlikely to cause significant problems, it could intensify side effects or reduce the effectiveness of one or both medications. Monitoring for changes in symptoms and your condition is recommended, and adjustments may be made if needed to manage any increased or more pronounced side effects.

Onset

Rapid: Onset of drug interaction typically occurs within 24 hours of co-administration.

Delayed: Onset of drug interaction typically occurs more than 24 hours after co-administration.

Evidence

Level of documentation of the interaction.

Established: The interaction is documented and substantiated in peer-reviewed medical literature.

Theoretical: This interaction is not fully supported by current medical evidence or well-documented sources, but it is based on known drug mechanisms, drug effects, and other relevant information.

How To Manage The Interaction

Provides a detailed discussion on how patients and clinicians can approach the identified drug interaction as well as offers guidance on what to expect and strategies to potentially mitigate the effects of the interaction. This may include recommendations on adjusting medication dosages, altering the timing of drug administration, or closely monitoring for specific symptoms.

It's important to note that all medical situations are unique, and management approaches should be tailored to individual circumstances. Patients should always consult their healthcare provider for personalized advice and guidance on managing drug interactions effectively.

Mechanism Of Interaction

The theorized or clinically determined reason (i.e., mechanism) why the drug-drug interaction occurs.

Disclaimer: The information provided on this page is for informational purposes only and should not be considered medical advice. Always consult with a qualified healthcare professional regarding your specific circumstances and medical conditions.

Where Does Our Information Come From?

Information for our drug interactions is compiled from several drug compendia, including:

• Gold Standard Drug Database
• Micromedex
• Lexicomp
• DrugBank

The prescribing information for each drug, as published on DailyMED, is also used. 

Individual drug-drug interaction detail pages contain references specific to that interaction. You can click on the reference number within brackets '[]' to see what reference was utilized.

The information posted is fact-checked by HelloPharmacist clinicians and reviewed quarterly.