Moxifloxacin Side Effects

Not all side effects for moxifloxacin may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

For the Consumer

Applies to moxifloxacin: oral tablet

Other dosage forms:

In addition to its needed effects, some unwanted effects may be caused by moxifloxacin. In the event that any of these side effects do occur, they may require medical attention.

You should check with your doctor immediately if any of these side effects occur when taking moxifloxacin:

  • Abdominal or stomach cramps
  • abdominal or stomach tenderness
  • black, tarry stools
  • bleeding gums
  • blisters
  • bloating or swelling of the face, arms, hands, lower legs, or feet
  • blood in the urine or stools
  • blurred vision
  • bone pain
  • burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
  • chest pain
  • chills
  • clay-colored stools
  • cough
  • crying
  • dark urine
  • diarrhea, watery and severe, which may also be bloody
  • difficult or labored breathing
  • difficulty with moving
  • difficulty with swallowing
  • discouragement
  • dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
  • dry mouth
  • excessive muscle tone
  • fainting
  • fast, irregular, pounding, or racing heartbeat or pulse
  • feeling of unreality
  • feeling of warmth or heat
  • feeling sad or empty
  • fever
  • flushed, dry skin
  • flushing or redness of the skin, especially on the face and neck
  • fruit-like breath odor
  • headache
  • hyperventilation
  • increased hunger
  • increased sensitivity of the skin to sunlight
  • increased thirst
  • increased urination
  • irregular heartbeat recurrent
  • irritability
  • joint pain, stiffness, or swelling
  • lack of coordination
  • loss of appetite
  • loss of interest or pleasure
  • lower back, side, or stomach pain
  • mood or mental changes
  • muscle aching or cramping
  • muscle pains or stiffness
  • muscle tension or tightness
  • nausea or vomiting
  • nervousness
  • noisy breathing
  • pain
  • pain in the pelvis
  • pain, warmth, or burning in the fingers, toes, and legs
  • painful or difficult urination
  • painful, swollen joints
  • pale skin
  • pinpoint red spots on the skin
  • pounding in the ears
  • problems with speech or speaking
  • problems with vision or hearing
  • quick to react or overreact emotionally
  • rapid weight gain
  • rapidly changing moods
  • redness or other discoloration of the skin
  • restlessness
  • seeing, hearing, or feeling things that are not there
  • seizures
  • sensation of the skin burning
  • sense of detachment from self or body
  • severe sunburn
  • shakiness in the legs, arms, hands, or feet
  • skin rash or itching
  • sore throat
  • sores, ulcers, or white spots on the lips or in the mouth
  • sweating
  • swelling of the feet or lower legs
  • swelling or puffiness of the face
  • swollen glands
  • tightness in the chest
  • tingling of the hands or feet
  • tiredness
  • trouble concentrating
  • trouble sleeping
  • troubled breathing with exertion
  • unexplained weight loss
  • unpleasant breath odor
  • unusual bleeding or bruising
  • unusual tiredness or weakness
  • unusual weight gain or loss
  • vomiting of blood
  • yellow eyes or skin
Incidence not known
  • Blistering, peeling, or loosening of the skin
  • burning, numbness, tingling, or painful sensations
  • change in the ability to see colors, especially blue or yellow
  • difficulty with chewing or talking
  • double vision
  • drooping eyelids
  • eye pain
  • general feeling of tiredness or weakness
  • hives
  • hoarseness
  • irregular or slow heart rate
  • large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
  • light-colored stools
  • muscle weakness
  • no blood pressure or pulse
  • puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
  • red, irritated eyes
  • red skin lesions, often with a purple center
  • severe headache
  • severe tiredness
  • stomach pain, continuing
  • stopping of heart
  • unconsciousness
  • unsteadiness or awkwardness
  • unusual behavior, such as disorientation to time or place, failure to recognize people, hyperactivity, or restlessness
  • weakness in the arms, hands, legs, or feet

Some of the side effects that can occur with moxifloxacin may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

  • Acid or sour stomach
  • bad, unusual, or unpleasant (after) taste
  • belching
  • burning feeling in the chest or stomach
  • change in sense of smell
  • change in taste
  • changes in vision
  • continuing ringing or buzzing or other unexplained noise in the ears
  • difficulty having a bowel movement (stool)
  • excess air or gas in the stomach or intestines
  • fear or nervousness
  • feeling of constant movement of self or surroundings
  • full feeling
  • general feeling of discomfort or illness
  • hearing loss
  • heartburn
  • impaired vision
  • indigestion
  • itching of the vagina or genital area
  • lack or loss of strength
  • loss of memory
  • pain during sexual intercourse
  • passing of gas
  • problems with memory
  • redness, swelling, or soreness of the tongue
  • sensation of spinning
  • sleepiness or unusual drowsiness
  • sore mouth or tongue
  • stomach discomfort, upset, or pain
  • thick, white vaginal discharge with no odor or with a mild odor
  • white patches in the mouth or on the tongue

For Healthcare Professionals

Applies to moxifloxacin: intravenous solution, oral tablet


Moxifloxacin has been generally well tolerated with most adverse events reported as mild to moderate and requiring no treatment. Moxifloxacin was discontinued due to adverse reactions in 5% of patients overall, 4.1% of patients received 400 mg orally, 3.9% received 400 mg intravenously, and 8.2% received 400 mg intravenous/oral sequential treatment. The most common side effects leading to discontinuation with the oral dose were nausea (0.8%), diarrhea (0.5%), dizziness (0.5%), and vomiting (0.4%). The most common side effect leading to discontinuation with the intravenous dose was rash (0.5%). The most common side effects leading to discontinuation with the intravenous/oral sequential dose were diarrhea (0.5%) and pyrexia (0.4%).[Ref]


Common (1% to 10%): Nausea (6.9%), diarrhea (6%), vomiting (2.4%), constipation (1.9%), abdominal pain (1.5%), upper abdominal pain (1.1%), dyspepsia (1%)
Uncommon (0.1% to 1%): Dry mouth, abdominal discomfort, abdominal distention, gastritis, gastroesophageal reflux disease, oral candidiasis, oral fungal infection, gastroenteritis, anorexia, flatulence
Frequency not reported: Clostridium difficile associated diarrhea, dysphagia, gastrointestinal disorder, pseudomembranous colitis, stomatitis, glossitis, tongue discoloration[Ref]

The onset of pseudomembranous colitis symptoms may occur during or after antimicrobial treatment. If diarrhea occurs and it is unresponsive to discontinuation of drug and/or standard therapy, pseudomembranous colitis should be considered.[Ref]

Nervous system

Common (1% to 10%): Headache (4.2%), dizziness (3%), insomnia (1.9%)
Uncommon (0.1% to 1%): Somnolence, tremor, dysgeusia, lethargy, paresthesia, tension headache, hallucinations, hypoesthesia, syncope, tinnitus, vertigo
Rare (less than 0.1%): Orofacial dyskinesia (at least 1 case)
Frequency not reported: Amnesia, aphasia, confusion, convulsions of various clinical manifestations (including grand mal convulsions), incoordination, parosmia, sleep disorders, speech disorders, abnormal thinking, sensory and sensorimotor axonal polyneuropathy (resulting in paresthesias, hypoesthesias, dysesthesias, weakness)
Postmarketing reports: Altered coordination, abnormal gait, exacerbation of myasthenia gravis, muscle weakness, peripheral neuropathy (may be irreversible), polyneuropathy, hearing impairment (including deafness; reversible in most cases)[Ref]


Uncommon (0.1% to 1%): Atrial fibrillation, palpitations, tachycardia, congestive cardiac failure, angina pectoris, cardiac failure, cardiac arrest, bradycardia, hypertension, hypotension, phlebitis, increased blood pressure, prolonged electrocardiogram QT interval
Frequency not reported: Abnormal ECG, arrhythmias, atrial flutter, ST-T wave changes, supraventricular tachycardia, cardiac arrhythmia (not otherwise specified), vasodilation, ventricular extrasystoles, ventricular tachycardia
Postmarketing reports: Ventricular tachyarrhythmias (including in very rare cases cardiac arrest and torsade de pointes, and usually in patients with concurrent severe underlying proarrhythmic conditions)[Ref]

The mean QTc interval prolongation in a study of 787 patients receiving moxifloxacin was 6 msec vs. 1 msec for a comparator group of patients receiving another antibiotic. There were 38 outliers in the moxifloxacin group (QTc interval greater than 450 msec for men or 470 msec for women) vs. 28 outliers in the comparator group.

In another study (n=48), there were greater increases in the QT and QTc interval with 800 mg moxifloxacin than with 1000 mg levofloxacin or 1500 mg ciprofloxacin.

Elderly patients experienced more ECG abnormalities than younger patients.[Ref]


Increased MCH, neutrophils, WBCs, albumin, and PT ratio, and decreased hemoglobin, RBCs, neutrophils, eosinophils, basophils, and PT ratio have been reported in greater than or equal to 2% of patients; however, it has not been determined if these laboratory abnormalities were due to the drug or the underlying condition being treated.[Ref]

Common (1% to 10%): Anemia (1.1%), increased MCH, increased neutrophils, increased WBCs, increased albumin, increased PT ratio, decreased hemoglobin, decreased RBCs, decreased neutrophils, decreased eosinophils, decreased basophils, decreased PT ratio
Uncommon (0.1% to 1%): Prolonged prothrombin time, thrombocythemia, eosinophilia, neutropenia, thrombocytopenia, leukocytosis, leukopenia, increased platelet count, decreased hemoglobin, increased white blood cell count, decreased hematocrit, increased eosinophil count, prolonged activated partial thromboplastin time
Frequency not reported: Increased prothrombin (decreased prothrombin time, decreased INR), decreased thromboplastin, decreased prothrombin (increased INR)
Postmarketing reports: Agranulocytosis, pancytopenia[Ref]


Common (1% to 10%): Increased alanine aminotransferase (1.1%), increased bilirubin, decreased bilirubin
Uncommon (0.1% to 1%): Abnormal liver function tests, abnormal hepatic function, increased aspartate aminotransferase, increased transaminases, increased blood bilirubin, increased hepatic enzyme, increased gamma-glutamyltransferase
Frequency not reported: Jaundice (primarily cholestatic), acute fulminant hepatic failure, acute liver injury
Postmarketing reports: Hepatic failure (including fatal cases), jaundice, acute hepatic necrosis, hepatitis (primarily cholestatic)[Ref]

Increased and decreased bilirubin have been reported in greater than or equal to 2% of patients; however, it has not been determined if these laboratory abnormalities were due to the drug or the underlying condition being treated.

A 69-year-old male developed jaundice, pruritus, weight loss, dark urine, elevated lever function tests (total bilirubin, 28.45 mg/dL; conjugated bilirubin, 20.6 mg/dL; alkaline phosphatase, 249 units/L; ALT, 58 units/L) 3 weeks after a 5-day course of oral moxifloxacin. A liver biopsy showed portal inflammatory infiltrates with lymphocytes and eosinophils and predominantly casts in canaliculi. Liver function tests normalized over 2 months.

A 23-year-old female developed acute fulminant hepatitis (transaminases up to 8500 units/L) with hepatocellular necrosis, toxic epidermal necrolysis, and encephalopathy after 3 days of moxifloxacin treatment. The condition culminated in multiple organ failure, acute respiratory distress syndrome, and death, despite a liver transplant.[Ref]


Common (1% to 10%): Hypokalemia (1%), increased ionized calcium, increased chloride, increased globulin, decreased glucose, decreased pO2, decreased amylase
Uncommon (0.1% to 1%): Hyperglycemia, hypoglycemia, hyperlipidemia, decreased appetite, dehydration, increased blood alkaline phosphatase, increased blood amylase, increased blood lactate dehydrogenase, increased blood glucose, increased lipase, increased blood triglycerides, increased blood uric acid
Frequency not reported: Dehydration (secondary to diarrhea or reduced fluid intake), hyperuricemia[Ref]

Increased ionized calcium, chloride, and globulin, and decreased glucose, pO2, and amylase have been reported in greater than or equal to 2% of patients; however, it has not been determined if these laboratory abnormalities were due to the drug or the underlying condition being treated.[Ref]


Common (1% to 10%): Pyrexia (1.1%)
Uncommon (0.1% to 1%): Fatigue, chest pain, asthenia, peripheral edema, pain, malaise, edema, chills, chest discomfort, candidiasis, fungal infection, facial pain
Frequency not reported: Pelvic pain, leg pain, back pain, abnormal laboratory test (not specified), taste loss, taste perversion, tongue discoloration[Ref]


Uncommon (0.1% to 1%): Back pain, pain in extremity, arthralgia, myalgia, muscle spasms, musculoskeletal chest pain, musculoskeletal pain
Frequency not reported: Arthritis, hypertonia, tendon disorder
Postmarketing reports: Tendon rupture[Ref]


Frequency not reported: Allergic reaction, face edema
Postmarketing reports: Anaphylactic reaction, anaphylactic shock, angioedema (including laryngeal edema)[Ref]


Uncommon (0.1% to 1%): Nervousness, confusional state, agitation, depression, restlessness, disorientation, anxiety
Frequency not reported: Abnormal dreams, depersonalization, depression (potentially culminating in self-endangering behavior), emotional lability
Postmarketing reports: Psychotic reaction (very rarely culminating in self-injurious behavior, such as suicidal ideation/thoughts or suicide attempts)[Ref]


Uncommon (0.1% to 1%): Rash, pruritus, hyperhidrosis, erythema, allergic dermatitis, night sweats, urticaria
Frequency not reported: Maculopapular rash, purpuric rash, pustular rash
Postmarketing reports: Toxic epidermal necrolysis, photosensitivity/phototoxicity reactions, Stevens-Johnson syndrome[Ref]


Uncommon (0.1% to 1%): Dysuria, vulvovaginal candidiasis, vulvovaginal mycotic infection, vaginal infection, vulvovaginal pruritus
Frequency not reported: Vaginitis[Ref]


Uncommon (0.1% to 1%): Infusion site extravasation
Frequency not reported: Injection site reactions (including phlebitis)[Ref]


Uncommon (0.1% to 1%): Blurred vision
Frequency not reported: Amblyopia, abnormal vision (visual disturbances temporally associated with central nervous system [CNS] symptoms)
Postmarketing reports: Vision loss (especially in the course of CNS reactions, transient in most cases)[Ref]


Uncommon (0.1% to 1%): Increased blood creatinine, increased blood urea, renal failure, acute renal failure
Frequency not reported: Abnormal kidney function
Postmarketing reports: Renal dysfunction, interstitial nephritis[Ref]


Uncommon (0.1% to 1%): Dyspnea, wheezing, bronchospasm, asthma
Postmarketing reports: Allergic pneumonitis[Ref]


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