[2S - [2α,5α,6β(S*)]] - 6 - [(aminophenylacetyl)amino] - 3,3 - dimethyl - 7 - oxo - 4 - thia - 1 - azabicyclo[3.2.0]heptane - 2 - carboxylic acid

Absorption
Well absorbed from GI tract. C max is approximately 3 mcg/mL (500 mg capsules) and 3.4 mcg/mL (500 mg oral suspension). Food affects absorption; take on empty stomach.

Distribution
Diffuses readily into most body tissues and fluids; penetrates into the CSF and brain only when meninges are inflamed. Approximately 20% protein bound; excreted in breast milk.

Elimination
Excreted largely unchanged in the urine.

Special Populations
Renal Function Impairment
T 1/2 may be prolonged. Dosing interval adjustments may be necessary.

Allopurinol
Increases potential for ampicillin-induced skin rash.

Atenolol
Antihypertensive and antianginal effects may be impaired.

Contraceptives, oral
May reduce efficacy of oral contraceptives.

Tetracyclines
May impair bactericidal effects of ampicillin.