• you are allergic to any ingredient in Cipro or to any other fluoroquinolone (eg, levofloxacin)
• you are taking tizanidine or you have recently received a live oral typhoid vaccine.

Contact your doctor or health care provider right away if any of these apply to you.

Some medical conditions may interact with Cipro. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:

• if you are pregnant, planning to become pregnant, or are breast-feeding
• if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
• if you have allergies to medicines, foods, or other substances
• if you have a stomach infection, liver problems, brain or nervous system problems, increased pressure in the brain, Alzheimer disease, brain blood vessel problems, muscle problems (eg, myasthenia gravis), or a history of seizures
• if you have a history of severe or persistent diarrhea, skin sensitivity to the sun, low blood potassium levels, heart problems, irregular heartbeat (eg, QT prolongation), or if you have a family member with a history of irregular heartbeat
• if you have a history of joint or tendon problems; rheumatoid arthritis; kidney problems or decreased kidney function; or heart, kidney, or lung transplant
• if you take corticosteroids (eg, prednisone) or you participate in strenuous physical work or exercise.

Some medicines may interact with Cipro. Tell your health care provider if you are taking any other medicines, especially any of the following:

• Antiarrhythmics (eg, amiodarone, quinidine) because the risk of serious side effects, including irregular heartbeat, may be increased.
• Corticosteroids (eg, prednisone) because they may increase the risk of tendon problems.
• Diuretics (eg, furosemide, hydrochlorothiazide), metoclopramide, nonsteroidal anti-inflammatory drugs (NSAIDs) (eg, ibuprofen), or probenecid because they may increase the risk of Cipro's side effects.
• Anticoagulants (eg, warfarin), antipsychotics (eg, clozapine), cyclosporine, methotrexate, monoamine oxidase inhibitors (MAOIs) (eg, phenelzine), serotonin norepinephrine reuptake inhibitors (SNRIs) (eg, duloxetine), sulfonylureas (eg, glyburide), theophylline, tizanidine, tricyclic antidepressants (eg, amitriptyline), or xanthines (eg, caffeine) because the risk of their side effects may be increased by Cipro.
• Hydantoins (eg, phenytoin) or live oral typhoid vaccine because their effectiveness may be decreased by Cipro.

This may not be a complete list of all interactions that may occur. Ask your health care provider if Cipro may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

Important safety information:

• Cipro may cause drowsiness, dizziness, blurred vision, or lightheadedness. These effects may be worse if you take it with alcohol or certain medicines. Use Cipro with caution. Do not drive or perform other possible unsafe tasks until you know how you react to it.
• Be sure to use Cipro for the full course of treatment. If you do not, the medicine may not clear up your infection completely. The bacteria could also become less sensitive to this or other medicines. This could make the infection harder to treat in the future.
• Long-term or repeated use of Cipro may cause a second infection. Tell your doctor if signs of a second infection occur. Your medicine may need to be changed to treat this.
• Cipro only works against bacteria; it does not treat viral infections (eg, the common cold).
• Avoid large amounts of food or drink that have caffeine (eg, coffee, tea, cocoa, cola, chocolate).
• Tell your doctor right away if you experience pain or swelling of a tendon or weakness or loss of use of a joint area. Rest the area and avoid exercise until further instruction from your doctor.
• Diabetes patients - Cipro may affect your blood sugar. Check blood sugar levels closely. Ask your doctor before you change the dose of your diabetes medicine.
• Cipro may cause you to become sunburned more easily. Avoid the sun, sunlamps, or tanning booths until you know how you react to Cipro. Use a sunscreen or wear protective clothing if you must be outside for more than a short time.
• Mild diarrhea is common with antibiotic use. However, a more serious form of diarrhea (pseudomembranous colitis) may rarely occur. This may develop while you use the antibiotic or within several months after you stop using it. Contact your doctor right away if stomach pain or cramps, severe diarrhea, or bloody stools occur. Do not treat diarrhea without first checking with your doctor.
• Use Cipro with caution in the elderly; they may be more sensitive to its effects (eg, tendon problems), especially if they take corticosteroids (eg, prednisone). They may also be more sensitive to other effects (eg, irregular heartbeat).
• Cipro should be used with extreme caution in children younger 18 years; they may be more sensitive to its effects, especially joint and tendon problems.
• Pregnancy and breast-feeding: If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using Cipro while you are pregnant. Cipro is found in breast milk. Do not breastfeed while taking Cipro.

Check with your doctor if any of these most common side effects persist or become bothersome:

Diarrhea; dizziness; headache; loss of appetite; nausea; stomach upset; vomiting.

Seek medical attention right away if any of these severe side effects occur:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); bloody or tarry stools; burning, numbness, tingling, pain, or weakness of the arms, hands, legs, or feet; chest pain; dark urine or unusual change in amount of urine; fainting; fever, chills, or unusual cough; hallucinations; inability to move or bear weight on a joint or tendon area; irregular heartbeat; loss of consciousness; moderate to severe sunburn; mood or mental changes (eg, new or worsening anxiety, agitation, confusion, depression, restlessness, sleeplessness); muscle pain or weakness; pain, soreness, redness, swelling, weakness, or bruising of a tendon or joint area; pale stools; persistent sore throat; red, swollen, blistered, or peeling skin; seizures; severe or persistent diarrhea; severe or persistent dizziness; stomach cramps/pain; suicidal thoughts or actions; tremors; unusual bruising or bleeding; unusual fatigue; vaginal yeast infection; vision changes; yellowing of the skin or eyes.

This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider.