If your symptoms do not improve within a few days, or if they become worse, check with your doctor.
For patients with low potassium levels, gemifloxacin may increase your risk of having a fast, slow or irregular heartbeat; loss of consciousness, or fainting spells. If these symptoms occur, tell your doctor right away.
This medicine may cause serious allergic reactions, including anaphylaxis, which can be life-threatening and require immediate medical attention. Call your doctor right away if you have a rash; itching; hives; hoarseness; shortness of breath; trouble breathing; trouble swallowing; or any swelling of your hands, face, or mouth after you take this medicine.
Serious side effects can occur during treatment with this medicine. Sometimes serious side effects can occur without warning. However, possible warning signs are including black, tarry stools; blistering, peeling, or loosening of the skin; bloody or cloudy urine; chills; decreased urination; diarrhea; fever; joint or muscle pain; red skin lesions, often with a purple center; sores, ulcers, or white spots in the mouth or on the lips; severe stomach pain; skin rash; swelling of the face, fingers, feet, and/or lower legs; unusual bleeding or bruising; or unusual weight gain. Stop taking this medicine and check with your doctor immediately if you notice any of these warning signs.
Liver problems can occur while using this medicine. Stop using this medicine and check with your doctor right away if you have dark urine, clay-colored stools, abdominal or stomach pain, or yellow eyes or skin.
Gemifloxacin may cause diarrhea, and in some cases it can be severe. It may occur 2 months or more after you stop using this medicine. Do not take any medicine to treat diarrhea without first checking with your doctor. Diarrhea medicines may make the diarrhea worse or make it last longer. If you have any questions about this or if mild diarrhea continues or gets worse, check with your doctor.
Tell your doctor right away if you start having numbness, tingling, or burning pain in your hands, arms, legs, or feet. These may be symptoms of a condition called peripheral neuropathy.
Gemifloxacin may rarely cause inflammation (tendinitis) or tearing of a tendon (the cord that attaches muscles to bones). This can occur while you are taking the medicine or after you finish taking it. The risk of having tendon problems may be increased if you are over 60 years of age, are using steroid medicines (e.g., dexamethasone, prednisolone, prednisone, or Medrol®), have severe kidney problems, have a history of tendon problems (e.g., rheumatoid arthritis), or if you have received an organ transplant (e.g., heart, kidney, or lung). Stop using this medicine and check with your doctor right away if you have sudden pain or swelling in a tendon after exercise (e.g., ankle, back of the knee or leg, shoulder, elbow, or wrist), bruise more easily after an injury, or are unable to bear weight or move the affected area. Refrain from exercise until your doctor says otherwise.
Some people who take gemifloxacin may become more sensitive to sunlight than they are normally. Exposure to sunlight, even for brief periods of time, may cause severe sunburn; skin rash, redness, itching, or discoloration. When you begin taking this medicine:
- Stay out of direct sunlight, especially between the hours of 10:00 a.m. and 3:00 p.m., if possible.
- Wear protective clothing, including a hat and sunglasses.
- Apply a sun block product that has a skin protection factor (SPF) of at least 15. Some people may require a product with a higher SPF number, especially if they have a fair complexion. If you have any questions about this, check with your doctor.
- Do not use a sun lamp or tanning bed or booth.
If you have a severe reaction from the sun, check with your doctor.
Gemifloxacin may cause some people to become dizzy, lightheaded, drowsy, or less alert than they are normally. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are dizzy or not alert. If these reactions are especially bothersome, check with your doctor.
Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.