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• Based on spectrum of activity, classified as an aminopenicillin. Aminopenicillins have enhanced activity against gram-negative bacteria compared with natural and penicillinase-resistant penicillins.
• Usually bactericidal.
• Like other β-lactam antibiotics, antibacterial activity results from inhibition of bacterial cell wall synthesis.
• Spectrum of activity includes many gram-positive and -negative aerobes and some anaerobes.
• Gram-positive aerobes: active in vitro and in clinical infections against Staphylococcus (β-lactamase-negative strains only), Streptococcus pneumoniae, other Streptococcus (α- and β-hemolytic strains only), and Enterococcus faecalis. Also active against Corynebacteriun and Listeria monocytogenes.
• Gram-negative aerobes: active in vitro and in clinical infections against H. influenzae, N. gonorrhoeae, E. coli, Proteus mirabilis, Salmonella, and Shigella. Also active in vitro against Bordetella pertussis, Eikenella corrodens, and Neisseria meningitidis. Inactive against Citrobacter, Enterobacter, Klebsiella, Providencia, and Serratia.
• Gram-positive and gram-negative bacteria that produce β-lactamases, including β-lactamase-producing S. aureus and E. faecalis, are resistant.
• Complete cross-resistance generally occurs between ampicillin and amoxicillin.

Advice to Patients

• Advise patients that antibacterials (including ampicillin) should only be used to treat bacterial infections and not used to treat viral infections (e.g., the common cold).
• Importance of completing the entire prescribed course of treatment, even if feeling better after a few days.
• Advise patients that skipping doses or not completing the full course of therapy may decrease effectiveness and increase the likelihood that bacteria will develop resistance and will not be treatable with ampicillin or other antibacterials in the future.
• Importance of taking oral ampicillin with a full glass of water 1 hour before or 2 hours after a meal.
• Importance of discontinuing therapy and informing clinician if an allergic reaction occurs.
• Importance of informing clinician of existing or contemplated concomitant therapy, including prescription and OTC drugs.
• Importance of women informing clinicians if they are or plan to become pregnant or plan to breast-feed.
• Importance of advising patients of other important precautionary information. (See Cautions.)

Preparations

Comparative Pricing

This pricing information is subject to change at the sole discretion of DS Pharmacy. For the most current and up-to-date pricing information, please visit drugstore.com.

AHFS Drug Information. © Copyright, 1959-2008, Selected Revisions August 2007. American Society of Health-System Pharmacists, Inc., 7272 Wisconsin Avenue, Bethesda, Maryland 20814.

† Use is not currently included in the labeling approved by the US Food and Drug Administration.

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.