Key takeaways

Ciprofloxacin, a fluoroquinolone antibiotic, is used to treat various bacterial infections but may cause side effects like nausea, neuropathy, and tendon damage.
Common side effects of ciprofloxacin include gastrointestinal issues, central nervous system effects, and sensitivity to sunlight, most of which are mild and self-limiting.
Serious side effects, although rare, can be permanent and disabling, including tendinitis with tendon rupture, peripheral neuropathy, and severe psychiatric disturbances, necessitating immediate discontinuation of the drug.
To avoid ciprofloxacin side effects, patients should follow their healthcare provider’s instructions closely, avoid certain medications and supplements that interact with ciprofloxacin, and protect themselves from excessive sunlight exposure.

Ciprofloxacin hydrochloride is in the class of fluoroquinolone antibiotics. Other fluoroquinolone antibiotics include levofloxacin, ofloxacin, and moxifloxacin. You may see or hear this drug referred to by the brand name, Cipro, which is manufactured by Bayer. Fluoroquinolone antibiotics work by inhibiting the enzymes that bacteria use to synthesize their DNA. This action prevents the bacteria from replicating.

Fluoroquinolones are highly effective and used to treat many types of bacterial infections and infectious diseases, including infections caused by antibiotic-resistant bacteria. The U.S. Food and Drug Administration (FDA) has approved ciprofloxacin for use in adults and children as young as infants.

Ciprofloxacin is not an over-the-counter medication. It is available by prescription only as an ointment, liquid, tablet, or extended-release tablet called Cipro XR. This article will cover some of the side effects, warnings, and interactions associated with ciprofloxacin use as well as how to avoid them.

Common side effects of ciprofloxacin

Ciprofloxacin use is associated with several common side effects. These side effects are usually not serious and often resolve on their own. Notify your healthcare provider if any of these side effects become worrisome or intolerable while taking ciprofloxacin.

Gastrointestinal symptoms including nausea, diarrhea, vomiting, indigestion, and abdominal pain
General symptoms of malaise including headache, dizziness, restlessness, lightheadedness, or disorientation
Difficulty sleeping including insomnia or nightmares
Psychiatric symptoms including anxiety, agitation, confusion, nervousness, delirium, paranoia, or hallucinations
Vaginitis (painful inflammation of the vagina)
Photosensitivity
Skin issues such as rashes or itching
Pain or inflammation in the muscles (myalgias), joints (arthralgias), or tendons (tendinitis)
Elevated liver enzymes
Central nervous system effects such as attention disturbances or impaired memory
Tremors
Hyperglycemia (elevated blood glucose)

Nausea

There is no reported incidence or prevalence data for how common ciprofloxacin-associated nausea occurs. Most individuals experiencing nausea after taking ciprofloxacin generally report that it is mild and self-limiting, meaning that it goes away on its own.

Serious side effects of ciprofloxacin

In a 2016 safety review, the FDA found that systemic (throughout the body) fluoroquinolone use is associated with uncommon, but potentially permanent and disabling adverse effects in the tendons, muscles, joints, nerves, and central nervous system (CNS). Some of these side effects have even occurred together including tendinitis with tendon rupture, combination peripheral neuropathies, and multiple central nervous system effects. Notify your prescribing doctor immediately if you are taking ciprofloxacin and experience any of these serious side effects. It is very likely the prescriber will discontinue the use of ciprofloxacin immediately and avoid future use of fluoroquinolones in anyone who experiences one or more of these serious adverse effects.

Peripheral nervous system effects including peripheral neuropathy, which may feel like numbness, tingling, or a prickling sensation similar to “pins and needles” in the arms and legs
Musculoskeletal effects including tendinitis, tendon rupture, muscle weakness, muscle pain, joint pain, joint swelling, or arthropathy
Central nervous system effects including increased intracranial pressure (ICP) and seizures
Psychiatric disturbances including toxic psychosis, suicidality, and depression
Worsening of myasthenia gravis
Severe hypersensitivity reactions and immune responses including severe skin rashes or reactions, anaphylaxis, jaundice (yellowing of the skin or eyes), and serum sickness
Cardiac system effects including aortic dissection, aortic aneurysm, and vasculitis
Heart rhythm problems including QT interval prolongation and torsades de pointes
Severe hypoglycemia (low blood glucose)
Disorders of the blood including blood dyscrasias and myelosuppression
Renal system involvement including crystals in the urine (crystalluria) and nephrotoxicity
Other bacterial infections including bacterial superinfection and C. difficile-associated diarrhea
Hepatotoxicity
Phototoxicity

Ciprofloxacin allergies

Although it is uncommon to have an allergic response to ciprofloxacin, there has been an increase in individuals reporting hypersensitivity reactions to quinolone antibiotics, including ciprofloxacin. A review in the International Journal of Clinical Pharmacy reported a 2% quinolone allergy in hospitalized patients in a single institution study. However, it is difficult to extrapolate this data to the general population and the true prevalence of allergic reactions to quinolones remains unknown.

While it is very rare to have a severe reaction to fluoroquinolones like ciprofloxacin, it is a good idea to know the signs of a very serious allergic reaction. If you are taking ciprofloxacin and notice any of the signs or symptoms of anaphylaxis below, you should seek medical attention right away.

Hives or an itchy skin rash
Swelling under the skin or in the face
Pale, cold, or clammy skin
Flushing, fever, or unprovoked sweating and shaking
Itching, swelling, or edema in the mucous membranes like the eyes, nose, tongue, lips, or mouth
Nausea, vomiting, or diarrhea
Trouble breathing, rapid breathing, wheezing, or coughing
Difficulty swallowing or speaking
Rapid heartbeat
Weak pulse
Fainting, dizziness, lightheadedness, collapsing, or losing consciousness
Mental confusion or agitation

Neuropathy

Peripheral neuropathy

The term peripheral neuropathy refers to a group of symptoms that occur in the extremities— usually the hands and feet—as a result of nerve damage outside of the brain and spinal cord. When the peripheral nerves are damaged, they can’t send messages from the brain and spinal cord to the skin, muscles, and other tissues. The result is often weakness, numbness, and pain in the area of distribution where the nerve innervates.

Ciprofloxacin-induced peripheral neuropathy has the potential to cause permanent damage in the setting of prolonged ciprofloxacin use. It is important to notify your healthcare provider if you are taking ciprofloxacin and notice any signs or symptoms of peripheral neuropathy such as numbness, tingling, weakness, or pain in the face, hands, or feet.

Optic neuropathy

Optic neuropathy is a specific type of peripheral neuropathy that occurs in the optic nerve of the eye. This nerve is responsible for transferring visual information from the eye to the brain, allowing you to see. Ciprofloxacin-induced optic neuropathy could result in permanent vision loss, though cases have been reported where vision was improved after discontinuing the medication. Notify your healthcare provider if you are taking ciprofloxacin and notice symptoms of optic neuropathy such as blurry vision or vision loss.

Tendon damage

Fluoroquinolones, including ciprofloxacin, are associated with tendinitis and tendon rupture, peripheral neuropathy, and CNS effects that may occur together. Tendinitis and tendon rupture may occur during treatment or months after treatment discontinues. The risk of tendinitis or tendon rupture is increased in all ages and further increases in patients over 60 years of age, patients taking corticosteroids, and patients with kidney, heart, and lung transplants. Discontinue use immediately and avoid fluoroquinolones in patients with adverse reactions.

How long do ciprofloxacin side effects last?

Possible side effects associated with ciprofloxacin usually begin shortly after starting the first dose and may remain throughout the course of treatment. While mild side effects (nausea, vomiting, diarrhea, abnormal liver function tests) and even some serious (cardiac) side effects usually resolve with discontinuation of the medication, it is important to note that some serious side effects may be permanent (tendon rupture, neuropathy) or even fatal (anaphylaxis). Some serious side effects (tendinitis, tendon rupture) have been reported to occur even in the months after ciprofloxacin has been discontinued.

Ciprofloxacin should be immediately discontinued if any signs or symptoms associated with peripheral neuropathy or hypersensitivity occur.

Ciprofloxacin contraindications and warnings

Abuse and dependence

Ciprofloxacin is not habit-forming or addictive. There have been no documented withdrawal symptoms associated with discontinuing the use of ciprofloxacin. As with any medication, you should speak with your healthcare provider before you stop taking the medication on your own.

Overdose

The maximum dose of ciprofloxacin varies according to the condition it is being used to treat. Additionally, weight may be a consideration in pediatric patients. Generally, the maximum dose of ciprofloxacin does not exceed 750 mg per dose.

As with any medication, especially antibiotics, ciprofloxacin should only be taken in the dosage, form, and frequency that it is prescribed by your healthcare provider. Taking more medication than is prescribed may result in acute renal failure or even a serious intestinal infection by the bacterium Clostridium difficile.

Restrictions

Ciprofloxacin has restricted use in certain individuals and has had recent updates by the FDA to strengthen its black box warnings label, which is the FDA’s most stringent warning for drugs. It is meant to provide important drug information related to serious side effects, such as injury or death, to the public and healthcare professionals. Ciprofloxacin is contraindicated for use in individuals who have:

Hypersensitivity to fluoroquinolones
Myasthenia gravis

Ciprofloxacin is contraindicated for use unless there is no other treatment option available in individuals with the following characteristics:

Older than 60 years of age
History or high risk of aortic aneurysm
Peripheral atherosclerotic vascular disease
Hypertension (elevated blood pressure)
Marfan syndrome or Ehlers-Danlos syndrome

Fluoroquinolone use should also be limited to individuals who have no alternative treatment options for the following indications:

Acute bacterial exacerbation of chronic bronchitis
Acute uncomplicated cystitis or uncomplicated urinary tract infections (UTIs)
Acute bacterial sinusitis

Ciprofloxacin use in pregnancy and while breastfeeding

There is no known risk of teratogenicity (harm or abnormalities in a developing fetus) if ciprofloxacin is taken during pregnancy. Due to conflicting data in human studies regarding the possible risk of spontaneous abortion, it is recommended to discuss the risk-to-benefit ratio of a pregnant woman with a healthcare provider before starting ciprofloxacin.

There is no data available to suggest that ciprofloxacin has any effect on milk production, but it does pass into breast milk. It is recommended that breastfeeding be avoided during treatment and for up to two days after discontinuing ciprofloxacin because there is an increased risk of infant C. difficile-associated diarrhea. If ciprofloxacin is being used to treat anthrax exposure in a nursing mother, it is then recommended to consider avoiding breastfeeding for three to four hours after the medication has been administered.

Ciprofloxacin interactions

Through various mechanisms of action, ciprofloxacin can interact with medications that are OAT3 substrates and CYP1A2 or CYP3A4 inhibitors. Concomitant administration of ciprofloxacin with these medications could lead to serious cardiac rhythm abnormalities such as QT prolongation or torsades de pointes. These combinations may also increase the risk for hypotension and other adverse events from inhibited hepatic metabolism.

Ciprofloxacin and theophylline

Some people with asthma, COPD, or emphysema may take a bronchodilator called theophylline. Ciprofloxacin can significantly increase the level of theophylline in the blood that could lead to serious or life-threatening side effects. It is important to give a full medication history to your healthcare provider before taking ciprofloxacin.

Ciprofloxacin and warfarin

Warfarin is a blood thinner medication used to help prevent stroke, heart attack, and death. Taking ciprofloxacin while taking warfarin could lead to a serious drug interaction with side effects such as severe bleeding events. Unless the prothrombin time can be monitored every other day to determine how quickly their blood clots, ciprofloxacin should generally not be prescribed to individuals taking warfarin.

Ciprofloxacin and glyburide

Ciprofloxacin has been shown to increase blood concentrations of the sulfonylurea drug, glyburide. People with diabetes who are taking glyburide or other oral hypoglycemic medications should notify their healthcare provider before starting ciprofloxacin. Monitoring blood glucose should occur throughout the duration of treatment with ciprofloxacin to avoid potentially life-threatening low blood sugar.

Ciprofloxacin and NSAIDs (non-steroidal anti-inflammatory drugs)

Many common medicines for pain relief are NSAIDs. Taking an NSAID while you take ciprofloxacin or other fluoroquinolones may increase the risk of serious central nervous system effects and seizures. It is important to notify your healthcare provider of any medications you may start taking after you have already begun treatment with ciprofloxacin.

Other interactions

Ciprofloxacin is also contraindicated for use with the following medications:

Cisapride
Eliglustat
Flibanserin
Lomitapide
Lonafarnib
Pimozide
Thioridazine
Tizanidine

How to avoid ciprofloxacin side effects

Follow medical advice while taking this medication. Take only the dose prescribed by a healthcare professional. Do not take more or less medication and all of the doses should be taken how and when they are prescribed. If you miss a dose, take the next dose as soon as you remember. Continue taking this medication even if feeling better after the first few doses.
Patients should disclose a full medication list, health history, and allergies before taking ciprofloxacin. This includes all medications and supplements, any medical conditions the patient has, or any allergic reactions they have had to medications in the past.
Store the medication correctly. Ciprofloxacin should be stored at room temperature (68 to 77 degrees Fahrenheit) and away from intense ultraviolet light.
Swallow the tablet whole or take the suspension exactly as it was prepared. Do not crush, break or chew the tablet or dilute the suspension.
Avoid taking ciprofloxacin with dairy products. It is okay to eat dairy products during the course of treatment with ciprofloxacin. However, it is best to avoid consuming high-calcium or calcium-fortified foods within two hours of taking this medication because they can delay the absorption of ciprofloxacin.
Avoid taking ciprofloxacin with antacids. Antacids that contain magnesium and aluminum salts will reduce the absorption of ciprofloxacin. Talk to your healthcare provider about alternative antacids if you are on an antacid treatment while taking ciprofloxacin.
Ciprofloxacin, and antibiotics in general, should only be taken for the exact amount of time recommended by your healthcare provider. For most bacterial infections, ciprofloxacin is taken daily for three to 14 days. For some very serious infections, ciprofloxacin may be prescribed for use for up to three months.
Avoid unnecessary sun exposure, sunbathing, or use of tanning beds. Ciprofloxacin can cause some individuals to experience sunburn due to an increased sensitivity to sunlight. You should use sunscreen when you are outside and wear sun-protective clothing like hats and long-sleeves while taking ciprofloxacin.
Seek immediate medical care if there is any type of allergic reaction to this medication. Allergic responses and hypersensitivity reactions to fluoroquinolones could be fatal and should be reported and treated as early as possible.