Do NOT use Trimox if:

• you are allergic to any ingredient in Trimox or another penicillin antibiotic (eg, ampicillin)
• you have recently received or will be receiving live oral typhoid vaccine
• you have infectious mononucleosis (mono).

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

Some medical conditions may interact with Trimox. 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 history of allergies, asthma, hay fever, or hives
• if you have had a severe allergic reaction (eg, severe rash, hives, breathing difficulties, dizziness) to a cephalosporin (eg, cephalexin) or another beta-lactam antibiotic (eg, imipenem)
• if you have kidney problems or gonorrhea.

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

• Anticoagulants (eg, warfarin) because the risk of bleeding may be increased
• Probenecid because it may increase the amount of Trimox in your blood
• Chloramphenicol, macrolide antibiotics (eg, erythromycin), sulfonamides (eg, sulfamethoxazole), or tetracycline antibiotics (eg, doxycycline) because they may decrease Trimox's effectiveness
• Methotrexate because the risk of its side effects may be increased by Trimox
• Live oral typhoid vaccine or hormonal birth control (eg, birth control pills) because their effectiveness may be decreased by Trimox.

This may not be a complete list of all interactions that may occur. Ask your health care provider if Trimox 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:

• Trimox may cause dizziness. This effect may be worse if you take it with alcohol or certain medicines. Use Trimox with caution. Do not drive or perform other possible unsafe tasks until you know how you react to it.
• Trimox only works against bacteria; it does not treat viral infections (eg, the common cold).
• Be sure to use Trimox 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 Trimox 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.
• 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.
• Hormonal birth control (eg, birth control pills) may not work as well while you are using Trimox. To prevent pregnancy, use an extra form of birth control (eg, condoms).
• Brown, yellow, or gray tooth discoloration has occurred rarely in some patients taking Trimox. It occurred most often in children. The discoloration was reduced or removed by brushing or dental cleaning in most cases. Contact your doctor if you experience this effect.
• Diabetes patients - Trimox may cause the results of some tests for urine glucose to be wrong. Ask your doctor before you change your diet or the dose of your diabetes medicine.
• Lab tests, including liver function, kidney function, and complete blood cell counts, may be performed if you use Trimox for a long period of time. These tests may be used to monitor your condition or check for side effects. Be sure to keep all doctor and lab appointments.
• Use Trimox with caution in the elderly; they may be more sensitive to its effects, especially patients with kidney problems.
• Use Trimox with extreme caution in children younger 10 years who have diarrhea or an infection of the stomach or bowel.
• Caution is advised when using Trimox in children younger 3 months; they may be more sensitive to its effects.
• Pregnancy and breast-feeding: If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using Trimox while you are pregnant. Trimox is found in breast milk. If you are or will be breast-feeding while you use Trimox, check with your doctor. Discuss any possible risks to your baby.

 Side effects

All medicines may cause side effects, but many people have no, or minor, side effects.

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

Diarrhea; nausea; 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 stools; confusion; dark urine; fever, chills, or persistent sore throat; red, swollen, blistered, or peeling skin; seizures; severe diarrhea; stomach pain or cramps; unusual bruising or bleeding; vaginal discharge or irritation; 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.