In this Article

• What is ampicillin (Principen)?
• What are the possible side effects of ampicillin (Principen)?
• What is the most important information I should know about ampicillin (Principen)?
• What should I discuss with my healthcare provider before taking ampicillin (Principen)?
• How should I take ampicillin (Principen)?
• What happens if I miss a dose (Principen)?
• What happens if I overdose (Principen)?
• What should I avoid while taking ampicillin (Principen)?
• What other drugs will affect ampicillin (Principen)?
• Where can I get more information?

What should I discuss with my healthcare provider before taking ampicillin (Principen)?

Do not use this medication if you are allergic to ampicillin or to any other penicillin antibiotic, such as:

• amoxicillin (Amoxil, Amoxicot, Biomox, Dispermox, Trimox);
• carbenicillin (Geocillin);
• dicloxacillin (Dycill, Dynapen);
• oxacillin (Bactocill); or
• penicillin (Beepen-VK, Ledercillin VK, Pen-V, Pen-Vee K, Pfizerpen, V-Cillin K, Veetids, and others).

To make sure you can safely take ampicillin, tell your doctor if you are allergic to any drugs (especially cephalosporins such as Omnicef, Cefzil, Ceftin, Keflex, and others), or if you have:

• asthma;
• kidney disease;
• a bleeding or blood clotting disorder;
• mononucleosis (also called "mono");
• a history of diarrhea caused by taking antibiotics; or
• a history of any type of allergy.

FDA pregnancy category B. Ampicillin is not expected to harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment.

Ampicillin can make birth control pills less effective, which may result in pregnancy. Before taking ampicillin, tell your doctor if you use birth control pills.

Ampicillin can pass into breast milk and may harm a nursing baby. You should not breast-feed while you are taking ampicillin.

How should I take ampicillin (Principen)?

Take exactly as prescribed by your doctor. Do not take in larger or smaller amounts or for longer than recommended. Follow the directions on your prescription label.

Take the medicine with a full glass of water.

Ampicillin should be taken on an empty stomach, at least 1 hour before or 2 hours after eating a meal.

To be sure this medicine is helping your condition, your blood will need to be tested often. Your liver and kidney function may also need to be tested. Visit your doctor regularly.

If you are being treated for gonorrhea, your doctor may also have you tested for syphilis, another sexually transmitted disease.

Take this medication for the full prescribed length of time. Your symptoms may improve before the infection is completely cleared. Ampicillin will not treat a viral infection such as the common cold or flu.

Do not share this medication with another person, even if they have the same symptoms you have.

This medication can cause unusual results with certain medical tests. Tell any doctor who treats you that you are using ampicillin.

Store at room temperature away from moisture, heat, and light.