Swelling, redness, or pain at the injection site may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly. Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects. Tell your doctor right away if you have any serious side effects, including: easy bruising/bleeding, unusual tiredness, symptoms of gallbladder disease (such as stomach/abdominal pain, nausea, vomiting), signs of kidney problems (such as change in the amount of urine), pink/bloody/dark urine, painful/frequent urination, back/side pain, yellowing eyes/skin, uncontrollable movements, confusion, seizures. This medication may rarely cause a severe intestinal condition due to a bacteria called C. difficile. This condition may occur during treatment or weeks to months after treatment has stopped. Tell your doctor right away if you develop: diarrhea that doesn't stop, abdominal or stomach pain/cramping, blood/mucus in your stool. If you have these symptoms, do not use anti-diarrhea or opioid products because they may make symptoms worse. Use of this medication for prolonged or repeated periods may result in oral thrush or a new yeast infection. Contact your doctor if you notice white patches in your mouth, a change in vaginal discharge, or other new symptoms. If ceftriaxone is mixed with a numbing medication (such as lidocaine) before injection into a muscle, it may rarely cause a serious blood problem (methemoglobinemia). Get medical help right away if you have any very serious side effects, including: pale/gray/blue skin, fast heartbeat, shortness of breath. A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing. This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist. In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch. In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Some products that may interact with this drug include: calcium-containing IV fluids. This medication may interfere with certain lab tests (such as certain urine glucose tests), possibly causing false test results. Make sure lab personnel and all your doctors know you use this drug.