Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.
Allergy: Allergic reactions to ampicillin are more common if you have a history of hay fever, hives, and other allergies. Reactions may include symptoms such as itching, hives, congestion, nausea, cramping, or diarrhea. Although much less common, more severe allergic reactions may include shortness of breath and swelling of the throat. If you experience these symptoms after taking this medication, stop taking the medication and get immediate medical attention.
If you have an allergy to this or related medications (e.g., penicillin, cephalexin), you should inform anyone involved with your medical care (e.g., doctor, pharmacist, nurse) and carry or wear easily accessible identification (such as a bracelet or necklace) alerting caregivers to the fact that your are allergic to penicillins.
Some people are "sensitive" (mild rash, upset stomach, etc.) to penicillins (e.g., amoxicillin, penicillin, ampicillin) while others are truly "allergic" (see symptoms above). As there may be times when it is most preferable to treat with penicillin (even if a person is "sensitive"), your doctor may test you to determine if you are truly allergic to this family of medications.
Blood cells: When ampicillin is taken for long periods of time, it can affect the amount of white blood cells, red blood cells, and platelets in the blood. If you are taking this medication for a long time, your doctor will monitor for this with blood tests.
Kidney function: If you have reduced kidney function, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
Liver function: This medication may affect your liver function if you take it for long periods of time. Your doctor will monitor for this with blood tests if needed.
Severe diarrhea: As with other antibiotics, ampicillin may cause severe diarrhea that is associated with a bacteria called C. difficile or colitis (inflammation of the colon). If you develop severe diarrhea, especially if it contains blood or mucus, stop taking this medication and contact your doctor immediately.
Skin rash: People with infectious mononucleosis, acute lymphocytic leukemia (ALL), or cytomegalovirus (CMV) infection are more likely to experience a rash from ampicillin.
If you have any of these conditions, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
Pregnancy: Ampicillin is safe to use during pregnancy.
Breast-feeding: This medication passes into breast milk. If you are a breast-feeding mother and are taking ampicillin, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.
Children: When infants and children less than 16 years of age take this medication, their doctor may monitor their liver, kidneys, and blood cells periodically while they are taking this medication.