Agent	Dosing schedule	Oral dose (mg)	IV dose	Comments
Penicillins
Amoxicillin	Every 8 to 12 hours	500	—	None
Amoxicillin-clavulanate potassium (Augmentin)	Every 8 to 12 hours	500/125	—	GI side effects*
Ampicillin-sulbactam (Unasyn)	Every 4 to 6 hours	—	150 to 200 mg per kg per day	GI side effects*
Aztreonam (Azactam)	Every 6 to 8 hours	—	1 to 2 g	Phlebitis; GI side effects*
Imipenem (Primaxin I.V.)	Every 6 hours	—	0.5 g	None
Piperacillin (Pipracil)	Every 6 hours	—	3 g	GI side effects*; phlebitis
Piperacillin-tazobactam (Zosyn)	Every 6 to 8 hours	—	3.375 g/4.5 g	GI side effects*; rash; headaches; insomnia
Ticarcillin-clavulanate (Timentin)	Every 4 to 6 hours	—	3.1 g	GI side effects*; rash; phlebitis
Cephalosporins
Cefotaxime (Claforan)	Every 8 to 12 hours	—	1 to 2 g	Thrombophlebitis
Ceftriaxone (Rocephin)	Once in 24 hours	—	1 to 2 g	Leukopenia; elevated BUN and liver enzyme levels
Cephalexin (Keflex)	Every 6 hours	500	—	GI side effects*
Fluoroquinolones
Ciprofloxacin (Cipro)	Every 12 hours	500	400 mg	Nausea; headache; photosensitivity; pregnancy category C
Enoxacin (Penetrex)	Every 24 hours	400	—	Pregnancy category C
Gatifloxacin (Tequin)	Every 24 hours	—	400 mg	Pregnancy category C
Levofloxacin (Levaquin)	Every 24 hours	250 to 750	250 to 750 mg	ECG QT prolongation; pregnancy category C
Lomefloxacin (Maxaquin)	Every 24 hours	400	—	Pregnancy category C
Norfloxacin (Noroxin)	Every 12 hours	400	—	Pregnancy category C
Ofloxacin (Floxin)	Every 12 hours	200 to 400	400 mg	Pregnancy category C
Aminoglycosides
Amikacin (Amikin)	Every 12 hours	—	7.5 mg per kg	Ototoxicity; nephrotoxicity
Gentamicin (Garamycin)	Every 24 hours	—	5 to 7 mg per kg	Ototoxicity; nephrotoxicity
Tobramycin (Nebcin)	Every 24 hours	—	5 to 7 mg per kg	Ototoxicity; nephrotoxicity
Other antibiotics
TMP-SMX (Bactrim; Septra)	Every 12 hours	160/800	8 to 10 mg per kg (TMP)	G6PD deficiency; sulfa allergy; do not use in third trimester