Along with its needed effects, moxifloxacin may cause some unwanted or undesirable effects. Generally, moxifloxacin is well tolerated and many people will not experience unwanted effects. The frequency and severity of these effects is dependant on many factors including dose, duration of therapy and individual susceptibility. Possible unwanted effects include:

• diarrhea
• nausea
• vomiting
• headache
• dizziness
• trouble sleeping
• stomach discomfort

Uncommon:

• agitation
• tremors
• seizures
• shortness of breath
• confusion

Rare:

• rash
• pseudomembranous colitis (inflammation of the colon caused by the overgrowth and toxin production of bacteria that are not killed by the antibiotic)
• abnormal heart rhythmns

Moxifloxacin is an antibiotic medication that kills various bacteria. It works by inhibiting the synthesis of bacterial DNA which results in bacterial cell death. Moxifloxacin does not kill all types of bacteria, but only those that have a sensitivity to this antibiotic. Infections caused by bacteria that are not sensitive to moxifloxacin will not show improvement after taking this medication.

Use as directed. Many antacids and multivitamins may interfere with the absorption of moxifloxacin. You should take moxifloxacin either four hours before or eight hours after taking these products. Allergic reactions have been reported with moxifloxacin. The reaction can be immediate and severe. Allergic symptoms include wheezing, hives, itching, swelling, joint and muscle pain, difficulty breathing, fever and skin rashes. Nausea and vomiting are not symptoms of an allergic reaction.

Diabetics should monitor their blood sugar regularly while taking levofloxacin. Discontinue the medication and notify your doctor if a hypoglycemic (low blood sugar) reaction occurs.
Taking the antibiotic repeatedly or for prolonged periods may result in bacterial or fungal overgrowth which can lead to a second infection. When this occurs, the moxifloxacin may need to be stopped and another antibiotic prescribed to treat the new infection.
Diarrhea may develop while taking moxifloxacin. This is sometimes caused by an overgrowth of bacteria in the gut that are not killed by the antibiotic. In severe cases, this may be life threatening and would require treatment with other antibiotics. In mild cases, symptoms disappear shortly after the drug is discontinued.
Moxifloxacin may make you more sensitive to sunlight. Wear sunscreens and protective clothing and avoid exposure to the sun for long periods of time.

If you experience joint or muscle pain while taking moxifloxacin, notify your doctor, rest and do not exercise. There are some reports of tendon tears (mostly in the ankle) occurring during treatment with drugs related to moxifloxacin.
Drug Interactions: It is important to tell your doctor and pharmacist of any prescription or over-the-counter medications you are taking. In some cases, the dose of one or both drugs may need to be altered or another drug may be prescribed. The following drugs or drug classes may interact with moxifloxacin:

• antacids that contain aluminum or magnesium
• iron or mineral supplements
• zinc-containing products
• warfarin (e.g. Coumadin®)
• hypoglycemic drugs (e.g. glyburide, insulin)
• sucralfate (e.g. Sulcrate®)
• theophylline (e.g. Theo-Dur®)

Use is not recommended in the following situations:

• allergy to moxifloxacin or any quinolone (e.g. ciprofloxacin, ofloxacin)
• patients with abnormal heart rhythms
• patients taking medications for abnormal heart rhythms

Caution is recommended in the following situations:

• kidney disease
• nervous system disorders (e.g. epilepsy)
• low potassium
• liver disease

Use in pregnancy: Current information suggests low risk, however, consult your doctor or pharmacist before use.
Use while breastfeeding: Moxifloxacin enters breast milk. Consult your doctor or pharmacist before you begin breastfeeding. Consult your doctor or pharmacist if you have any questions.