Table: Usual Dosages of Commonly Prescribed Antibiotics[a]-MSD Manual Professional Edition

Usual Dosages of Commonly Prescribed Antibiotics[a]

Drug	Adult Dosage	Pediatric (Age > 1 Month) Dosage	Dosage in Renal Failure[b] (Creatinine Clearance < 10 mL/minute)
Aminoglycosides
	N/A	15 mg/kg IV once/day or 7.5 mg/kg every 12 hours	15 mg/kg IV once/day or 7.5 mg/kg IV every 12 hours	N/A	5–7.5 mg/kg IV every 12 hours	1.5–2.5 mg/kg IV every 24–48 hours
	N/A	5–7 mg/kg IV once/day or 1.7 mg/kg IV every 8 hours	5–7 mg/kg IV once/day	N/A	1–2.5 mg/kg IV every 8 hours	0.34–0.51 mg/kg IV every 24–48 hours
	N/A	1 mg/kg IV every 8 hours	N/A	N/A	1 mg/kg IV every 8 hours	Infectious disease consultation required for dosage Dosage adjusted to achieve peak serum concentration of 3–4 mcg/mL (6.3–8.4 micromol/L) and trough concentration of < 1 mcg/mL (2.1 micromol/L)

	1 g for 3 doses (eg, at 1, 2, and 11 PM on the day before surgery)	N/A	N/A	15 mg/kg every 4 hours for 2 days or 25 mg/kg at 1, 2, and 11 PM on the day before surgery	N/A	N/A
For hepatic coma	1–3 g 4 times a day	N/A	N/A	0.6–1.75 g/m² every 6 hours or 0.4–1.2 g/m² every 4 hours	N/A	N/A

For tuberculosis	N/A	15 mg/kg IM every 24 hours (maximum: 1.0 g/day) initially, then 1.0 g 2–3 times/week	N/A	N/A	20–40 mg/kg IM once/day	7.5 mg/kg IM every 72–96 hours (maximum: 1 g)
For synergy with a cell wall–active antibiotic to treat enterococcal endocarditis	N/A	7.5 mg/kg IM every 12 hours	N/A	N/A	N/A	N/A
	N/A	5–7 mg/kg IV once/day or 1.7 mg/kg IV every 8 hours	5–7 mg/kg IV once/day or 1.7 mg/kg IV every 8 hours	N/A	1–2.5 mg/kg IV every 8 hours	0.34–0.51 mg/kg IV every 24–48 hours
Beta-lactams: Cephalosporins (1st generation)
	0.5–1 g every 12 hours	N/A	N/A	15 mg/kg every 12 hours	N/A	0.5 g orally every 36 hours
	N/A	1–2 g IV every 8 hours	2 g IV every 8 hours	N/A	16.6–33.3 mg/kg IV every 8 hours	1–2 g IV every 24–48 hours
	0.25–0.5 g every 6 hours	N/A	N/A	6.25–12.5 mg/kg every 6 hours or 8.0–16 mg/kg every 8 hours	N/A	0.25–0.5 g orally every 24–48 hours
Beta-lactams: Cephalosporins (2nd generation)
[c]	0.25–0.5 g every 8 hours	N/A	N/A	10–20 mg/kg every 12 hours or 6.6–13.3 mg/kg every 8 hours	N/A	0.5 g orally every 12 hours
	N/A	1–3 g IV every 12 hours	2–3 g IV every 12 hours	N/A	20–40 mg/kg IV every 12 hours	1–3 g IV every 48 hours
	N/A	1 g IV every 8 hours to 2 g IV every 4 hours	2 g IV every 4 hours or 3 g IV every 6 hours	N/A	27–33 mg/kg IV every 8 hours or, for severe infections, 25–40 mg/kg every 6 hours	0.5–1.0 g IV every 24–48 hours
	0.25 g every 12 hours or 0.5 g every 12–24 hours	N/A	N/A	15 mg/kg every 12 hours for otitis media	N/A	0.25 g orally every 12–24 hours
	0.125–0.5 g every 12 hours	0.75–1.5 g IV every 6–8 hours	1.5 g IV every 6 hours	10–15 mg/kg suspension every 12 hours For older children: 125–250-mg tablets every 12 hours	25–50 mg/kg IV every 8 hours	0.25–0.5 g orally every 24 hours or 0.75 g IV every 24 hours
For meningitis	—	—	3 g IV every 8 hours	—	50–60 mg/kg IV every 6 hours	—
Beta-lactams: Cephalosporins (3rd generation)
	N/A	1 g every 12 hours to 2 g IV every 4 hours	2 g IV every 4 hours	N/A	8.3–33.3 mg/kg IV every 4 hours or 16.6–66.6 mg/kg every 6 hours	1–2 g IV every 24 hours
[d]	0.1–0.4 g every 12 hours	N/A	N/A	5 mg/kg every 12 hours	N/A	0.1–0.4 g orally every 24 hours
	N/A	1 g IV every 12 hours to 2 g every 8 hours	2 g IV every 8 hours	N/A	25–50 mg/kg IV every 8 hours	0.5 g IV every 24–48 hours
	N/A	2.5 g IV every 8 hours	2.5 g IV every 8 hours	N/A	N/A	0.94 g IV every 24–48 hours
Ceftibuten[c]	0.4 g every 24 hours	N/A	N/A	9 mg/kg once/day	N/A	0.1 g orally every 24 hours
	N/A	1–2 g IV every 24 hours	2 g IV every 24 hours	N/A	50–75 mg/kg IV every 24 hours or 25–37.5 mg/kg every 12 hours	Same as adult dose
For meningitis	N/A	2 g IV every 12 hours	2 g IV every 12 hours	N/A	50 mg/kg IV every 12 hours or 100 mg/kg every 24 hours (not to exceed 4 g/day) Possibly a loading dose of 100 mg/kg IV (not to exceed 4 g) at the start of therapy	2 g IV every 12 hours
Beta-lactams: Cephalosporins (4th generation)
	N/A	1–2 g IV every 8–12 hours	2 g IV every 8 hours	N/A	50 mg/kg IV every 8–12 hours	0.25–1 g IV every 24 hours
Beta-lactams: Cephalosporins (5th generation)
	N/A	0.6 g IV every 12 hours	0.6 g IV every 12 hours	N/A	N/A	0.2 g IV every 12 hours
Novel cephalosporins
(1.5 g = ceftolozane 1 g + tazobactam 0.5 g)	N/A	1.5 g IV every 8 hours	1.5 g IV every 8 hours	N/A	N/A	0.75 g IV once, then 0.15 g IV every 8 hours
	N/A	2 g IV every 8 hours	2 g IV every 8 hours	N/A	N/A	0.75 g IV every 12 hours
Beta-lactams: Penicillins
	0.25–0.5 g every 8 hours or 0.875 g every 12 hours	N/A	N/A	12.5–25 mg/kg every 12 hours or 7–13 mg/kg every 8 hours	N/A	0.25–0.5 g orally every 24 hours
For endocarditis prophylaxis	2 g for 1 dose	N/A	N/A	50 mg/kg 1 hours before procedure	N/A	2 g orally for 1 dose
	0.25–0.5 g every 8 hours or 0.875 g every 12 hours	N/A	N/A	If > 40 kg: Adult dose	N/A	0.25–0.5 g orally every 24 hours
	N/A	N/A	N/A	45 mg/kg every 12 hours	N/A	N/A
	2 g every 12 hours	N/A	N/A	N/A	N/A	N/A
	N/A	0.5–2.0 g IV every 4–6 hours	2 g IV every 4 hours	N/A	25–50 mg/kg IV every 6 hours	0.5–2.0 g IV every 12–24 hours
For meningitis	N/A	2 g IV every 4 hours	2 g IV every 4 hours	N/A	50–100 mg/kg IV every 6 hours	2 g IV every 12 hours
(3 g =+ 1 g sulbactam)	N/A	1.5–3.0 g IV every 6 hours	3 g IV every 6 hours	N/A	25–50 mg/kg IV every 6 hours	1.5–3.0 g IV every 24 hours
[c]	0.125–0.5 g every 6 hours	N/A	N/A	3.125–6.25 mg/kg every 6 hours	N/A	0.125–0.5 g orally every 6 hours
	Rarely used	1–2 g IV every 4 hours	2 g IV every 4 hours	N/A	12.5–25 mg/kg IV every 6 hours or 8.3–33.3 mg/kg every 4 hours	1–2 g IV every 4 hours
	Rarely used	1–2 g IV every 4 hours	2 g IV every 4 hours	N/A	12.5–25 mg/kg IV every 6 hours or 8.3–33.3 mg/kg IV every 4 hours	1–2 g IV every 4 hours
[c]	N/A	1–4 million units IV every 4–6 hours	4 million units IV every 4 hours	N/A	6,250–100,000 units/kg IV every 6 hours or 4,166.6–66,666 units/kg IV every 4 hours	0.5–2 million units IV every 4–6 hours (maximum total daily dose: 6 million units/day)
	0.25–0.5 g every 6–12 hours	N/A	N/A	6.25–12.5 mg/kg every 8 hours	N/A	N/A
(IM only)
For streptococcal pharyngitis	N/A	1.2 million units IM for 1 dose	N/A	N/A	25,000–50,000 units/kg IM as a single dose or If < 27 kg: 300,000–600,000 units as a single dose or If ≥ 27 kg: 0.9 million units as a single dose	1.2 million units IM for 1 dose
Prophylaxis for rheumatic fever	N/A	1.2 million units IM every 3–4 weeks	N/A	N/A	25,000–50,000 units/kg IM every 3–4 weeks	1.2 million units IM every 3–4 weeks
For early syphilis	N/A	2.4 million units IM for 1 dose	N/A	N/A	50,000 units/kg IM for 1 dose	2.4 million units IM for 1 dose
For late syphilis (excluding neurosyphilis)	N/A	2.4 million units IM/week for 3 weeks	N/A	N/A	50,000 units/kg IM in 3 doses 1 week apart	2.4 million units IM for 1 dose
(IM only)	N/A	0.3–0.6 million units IM every 12 hours	N/A	N/A	25,000–50,000 units/kg IM every 24 hours or 12,500–25,000 units/kg IM every 12 hours	0.3 to 0.6 million units IM every 12 hours
Piperacillin (1.9 mEq sodium/g)	N/A	3 g IV every 4–6 hours	3 g IV every 4 hours	N/A	50–75 mg/kg IV every 6 hours or 33.3–50 mg/kg IV every 4 hours	3–4 g IV every 12 hours
(2.25 g = 2.0 g piperacillin + 0.25 g	N/A	3.375 g IV every 6 hours	3.375 g IV infused over 4 hours every 8 hours or 4.5 g IV every 6 hours	N/A	80 mg/kg IV every 8 hours	2.25 g IV every 8 hours to 4.5 g IV every 12 hours
Beta-lactams: Monobactams
	N/A	1–2 g IV every 6–12 hours	2 g IV every 6 hours	N/A	30–40 mg/kg IV every 6–8 hours	0.5 g IV every 8 hours
Beta-lactams: Carbapenems
	N/A	1 g IV every 24 hours	1 g IV every 24 hours	N/A	N/A	0.5 g IV every 24 hours
Imipenem	N/A	0.5–1.0 g IV every 6 hours	1 g IV every 6 hours	N/A	For infants 4 weeks to 3 months: 25 mg/kg IV every 6 hours For children >3 months: 15–25 mg/kg IV every 6 hours	0.125–0.25 g IV every 12 hours (may increase risk of seizures)
	N/A	1 g IV every 8 hours	2 g IV every 8 hours	N/A	20–40 mg/kg IV every 8 hours	0.5 g IV every 24 hours
For meningitis	N/A	2g IV every 8 hours	2 g IV every 8 hours	N/A	40 mg/kg IV every 8 hours	1 g IV every 24 hours
	N/A	4 g IV every 8 hours	4 g IV every 8 hours	N/A	N/A	1g IV every 12 hours
	N/A	0.5 g IV every 8 hours	0.5 g IV every 8 hours	N/A	N/A	0.25 g IV every 24 hours
Fluoroquinolones[e]
	0.5–0.75 g every 12 hours	0.2–0.4 g IV every 8–12 hours	0.4 g IV every 8 hours	10–15 mg/kg IV every 12 hours (in select circumstances)	10–15 mg/kg IV every 12 hours (in select circumstances)	0.5–0.75 g orally every 24 hours or 0.2–0.4 g IV every 24 hours
Extended-release for uncomplicated cystitis	0.5 g every 24 hours for 3 days	N/A	N/A	N/A	N/A	N/A
	450 mg every 12 hours	300 mg IV every 12 hours	300 mg IV every 12 hours	N/A	N/A	N/A
	320 mg every 24 hours	N/A	N/A	N/A	N/A	160 mg orally every 24 hours
	0.25–0.75 g every 24 hours	0.25–0.75 IV g every 24 hours	0.75 g IV every 24 hours	N/A	N/A	0.25–0.5 g orally or IV every 48 hours
	0.4 g every 24 hours	0.4 g IV every 24 hours	0.4 g IV every 24 hours	N/A	N/A	0.4 g every 24 hours orally or IV
Norfloxacin[c]	0.4 g every 12 hours	N/A	N/A	N/A	N/A	0.4 g orally every 24 hours
	0.2–0.4 g every 12 hours	0.4 g IV every 12 hours	0.2–0.4 g IV every 12 hours	N/A	N/A	0.1–0.2 g orally or IV every 24 hours
Macrolides
	0.5 g on day 1, then 0.25 g every 24 hours for 4 days	0.5 g IV every 24 hours	0.5 g IV every 24 hours	—	N/A	0.5 g orally on day 1, then 0.25 g orally every 24 hours for 4 days or 0.5 g IV every 24 hours
For nongonococcal cervicitis and urethritis	1 g for 1 dose	N/A	N/A	N/A	N/A	N/A
For traveler’s diarrhea	1 g for 1 dose	N/A	N/A	5–10 mg/kg for 1 dose	N/A	N/A
For tonsillitis or pharyngitis	N/A	N/A	N/A	12 mg/kg for 5 days	N/A	N/A
For otitis media or community-acquired pneumonia	N/A	N/A	N/A	10 mg/kg on day 1, then 5 mg/kg once/day on days 2–5	N/A	N/A
	0.25–0.5 g every 12 hours Extended-release: 1 g every 24 hours	N/A	N/A	7.5 mg/kg every 12 hours	N/A	0.25–0.5 g orally every 24 hours
[c]	0.25–0.5 g every 6 hours	N/A	N/A	10–16.6 mg/kg every 8 hours or 7.5–12.5 mg/kg every 6 hours	N/A	0.25 g orally every 6 hours
For gastrointestinal preoperative bowel preparation	1 g for 3 doses	N/A	N/A	20 mg/kg for 3 doses	N/A	N/A
	N/A	0.5–1 g IV every 6 hours	1 g IV every 6 hours	N/A	3.75–5.0 mg/kg IV every 6 hours	0.5 g IV every 6 hours
	N/A	0.5–1 g IV every 6 hours	1 g IV every 6 hours	N/A	3.75–5.0 mg/kg IV every 6 hours	0.5 g IV every 6 hours
for Clostridioides difficile (formerly Clostridium difficile) infection	200 mg 2 times a day for 10 days	N/A	N/A	Weight-based dosing for infants ≥ 6 months and children: 16 mg/kg 2 times a day for 10 days; maximum: 200 mg/dose Fixed dosing for infants ≥ 6 months, children, and adolescents: 4 to < 7 kg, oral suspension: 80 mg 2 times a day for 10 days 7 to < 9 kg, oral suspension: 120 mg 2 times a day for 10 days 9 to < 12.5 kg, oral suspension: 160 mg 2 times a day for 10 days ≥ 12.5 kg, oral suspension, tablets: 200 mg 2 times a day for 10 days	N/A	N/A (minimal systemic absorption)
Sulfonamides and
Sulfisoxazole	1.0 g every 6 hours	25 mg/kg IV every 6 hours (not available in the US)	N/A	30–37.5 mg/kg every 6 hours or 20–25 mg/kg every 4 hours	N/A	1 g orally every 12–24 hours
Sulfamethizole	0.5–1 g every 6–8 hours	N/A	N/A	7.5–11.25 mg/kg every 6 hours	N/A	N/A
Sulfamethoxazole	1 g every 8–12 hours	N/A	N/A	25–30 mg/kg every 12 hours	N/A	1 g orally every 24 hours
	0.1 g every 12 hours or 0.2 g every 24 hours	N/A	N/A	2 mg/kg every 12 hours for 10 days for urinary tract infection	N/A	0.1 g orally every 24 hours
[f]	0.16/0.8 g every 12 hours	3–5 mg TMP/kg IV every 6–8 hours	5 mg TMP/kg IV every 6 hours	3–6 mg TMP/kg every 12 hours	3–6 mg TMP/kg IV every 12 hours	Not recommended if other alternatives are available
For Pneumocystis jirovecii pneumonia[f]	0.32/1.6 g every 8 hours for 21 days	5 mg TMP/kg IV every 8 hours for 21 days	5 mg TMP/kg IV every 6–8 hours	5–6.6 mg TMP/kg every 8 hours or 3.75–5 mg TMP/kg every 6 hours	5–6.6 mg TMP/kg IV every 8 hours or 3.75–5 mg TMP/kg IV every 6 hours	If essential, 5 mg TMP/kg IV every 24 hours or 1.25 mg TMP/kg IV every 6 hours
Tetracyclines
	0.1 g every 12 hours	0.1 g IV every 12 hours	0.1 mg IV every 12 hours	Age > 8 years: 2–4 mg/kg every 24 hours or 1–2 mg/kg every 12 hours	Age > 8 years: 2–4 mg/kg IV every 24 hours or 1–2 mg/kg IV every 12 hours	0.1 g IV or orally every 12 hours
	N/A	1 mg/kg IV every 12 hours	Same as adult dose	N/A	N/A	Same as adult dose
	0.1 g every 12 hours	0.1 g IV every 12 hours	0.1 g IV every 12 hours	N/A	N/A	0.1 g IV or orally every 12 hours
	0.45 g every 24 hours x 2 doses, then 0.3 g every 24 hours	0.2 g IV on day 1, then 0.1 g IV every 24 hours	Same as adult dose	N/A	N/A	Same as adult dose
[c]	0.25–0.5 g every 6 hours	N/A	N/A	Age > 8 years: 6.25–12.5 mg/kg every 6 hours	N/A
	N/A	100 mg, then 50 mg (25 mg for severe hepatic dysfunction) IV every 12 hours	Same as adult dose[g]	N/A	N/A	Same as adult dose
Others
	0.15–0.45 g every 6 hours	0.6 g IV every 6 hours to 0.9 IV g every 8 hours	0.9 g IV every 8 hours	2.6–6.6 mg/kg every 8 hours or 2–5 mg/kg every 6 hours	6.6–13.2 mg/kg IV every 8 hours or 5–10 mg/kg IV every 6 hours	0.15–0.45 g orally every 6 hours or 0.6–0.9 g IV every 6–8 hours
	0.25–1 g every 6 hours	0.25–1.0 g IV every 6 hours	1 g IV every 6 hours	N/A	12.5–18.75 mg/kg IV every 6 hours	0.25–1.0 g IV every 6 hours
For meningitis	N/A	12.5 mg/kg every 6 hours (maximum: 4 g/day)	12.5 mg/kg IV every 6 hours (maximum: 4 g/day)	N/A	18.75–25 mg/kg IV every 6 hours	12.5 mg/kg IV every 6 hours (maximum: 4 g/day)
Colistin (polymyxin E)	N/A	2.5–5 mg/kg/day IV in 2–4 doses	2.5–5 mg/kg/day IV in 2–4 doses[g]	N/A	N/A	1.5 mg/kg every 36 hours
	N/A	1500 mg as a single dose or 1000 mg once, followed by a 500-mg dose 1 week later	1500 mg as a single dose or 1000 mg once, followed by a 500-mg dose 1 week later	N/A	N/A	1125 mg as a single dose or 750 mg once, followed by a 375-mg dose 1 week later
	N/A	4–6 mg/kg IV every 24 hours	8–10 mg/kg IV every 24 hours[g]	N/A	N/A	4–6 mg/kg IV every 48 hours
	0.2 g every 12 hours	N/A	N/A	N/A	N/A	0.2 g orally every 12 hours
	A single dose of 3 g in 3–4 oz of water	Not available in the US	N/A	N/A	N/A	A single dose of 3 g in 3–4 oz of water
	0.6 g every 12 hours	0.15 g IV every 12 hours	Same as adult dose	N/A	N/A	Same as adult dose
	0.6 g every 12 hours	0.6 g IV every 12 hours	0.6 g IV every 12 hours	10 mg/kg every 8 hours	10 mg/kg IV every 8 hours	0.6 g IV or orally every 12 hours

For anaerobic infection	7.5 mg/kg every 6 hours (not to exceed 4 g/day)	7.5 mg/kg IV every 6 hours (not to exceed 4 g/day)	7.5 mg/kg IV every 6 hours (not to exceed 4 g/day)	7.5 mg/kg every 6 hours	7.5 mg/kg IV every 6 hours	3.75 mg/kg IV or orally every 6 hours (not to exceed 2 g/day)
For trichomoniasis	2 g for 1 dose or 0.5 g every 12 hours for 7 days	N/A	N/A	N/A	N/A	N/A
For Clostridioides difficile–induced diarrhea (pseudomembranous colitis)	0.5 g every 6–8 hours for 10–14 days	500 mg IV every 6–8 hours	500 mg IV every 6 hours	7.5 mg/kg every 8 hours	7.5 mg/kg IV every 6 hours	250 mg orally or IV every 8 hours
For amebiasis				11.6–16.6 mg/kg every 8 hours for 7–10 days	11.6–16.6 mg/kg IV every 8 hours for 7–10 days	N/A
For giardiasis	0.25 g every 6–8 hours for 5–7 days	N/A	N/A	5 mg/kg every 6–8 hours for 5 days	N/A	N/A
	50–100 mg every 6 hours	N/A	N/A	1.25–1.75 mg/kg every 6 hours	N/A	Not recommended
	100 mg every 12 hours	N/A	N/A	N/A	N/A	N/A
	N/A	1200 mg as a single dose	1200 mg as a single dose	N/A	N/A	1200 mg as a single dose
Quinupristin/dalfopristin	N/A	7.5 mg/kg IV every 8–12 hours	7.5 mg/kg IV every 8 hours	N/A	7.5 mg/kg IV every 12 hours for complicated skin or skin structure infection or 7.5 mg/kg every 8 hours for serious infections	7.5 mg/kg IV every 8–12 hours

For tuberculosis (as part of a 3- or 4-drug regimen)	0.6 g every 24 hours	0.6 g IV every 24 hours	N/A	5–10 mg/kg every 12 hours or 10–20 mg/kg every 24 hours	10–20 mg/kg IV every 24 hours	0.3–0.6 g IV or orally every 24 hours
For meningococcal exposure	0.6 g every 12 hours for 4 doses	N/A	N/A	Age ≥ 1 month: 10 mg/kg every 12 hours for 2 days Age < 1 month: 5 mg/kg every 12 hours for 2 days	N/A	0.6 g orally every 12 hours for 4 doses
For Haemophilus influenzae exposure	20 mg/kg every 24 hours for 4 days (not to exceed 600 mg every 24 hours)	N/A	N/A	20 mg/kg every 24 hours for 4 days Age < 1 month: 10 mg/kg every 24 hours for 4 days	N/A	20 mg/kg every 24 hours for 4 days (not to exceed 600 mg every 24 hours)
	0.3 g every 8 hours or 0.6–0.9 g every 24 hours	0.3 g IV every 8 hours or 0.6–0.9 g IV every 24 hours	0.3 g IV every 8 hours or 0.6–0.9 g IV every 24 hours	—	—	0.3 g IV or orally every 8 hours or 0.6–0.9 g IV or orally every 24 hours

For pulmonary tuberculosis (as part of a 3- or 4- drug regimen)	Initial phase (2 months): 0.6 g twice/week Continuation phase (4 months): 0.6 g once/week	N/A	N/A	N/A	N/A	N/A
	0.9 g once/week (3 months)	N/A	N/A	N/A	N/A	N/A
	200 mg every 24 hours	200 mg IV every 24 hours	200 mg IV every 24 hours	N/A	N/A	200 mg orally or IV every 24 hours
	N/A	10 mg/kg IV every 24 hours	10 mg/kg IV every 24 hours	N/A	N/A	N/A
	125 mg every 6 hours (only effective for C. difficile–induced diarrhea)	15 mg/kg IV every 12 hours (often 1 g every 12)	25 mg/kg once, then 15–20 mg/kg IV every 8–12 hours[g]	N/A	13 mg/kg IV every 8 hours or 10 mg/kg IV every 6 hours	0.5–1.0 g IV every week[h]
For meningitis[i]	N/A	N/A	15–20 mg/kg IV every 8–12 hours[h]	N/A	15 mg/kg IV every 6 hours	15 mg/kg IV every week[h]
[a] See also Recommended Dosages of Selected Parenteral Antibiotics for Neonates, Recommended Dosages of Select Aminoglycosides for Neonates, , and Recommended Dosages of Selected Oral Antibiotics for Neonates.
[b] Initial loading dose should be equivalent to the usual dose for patients with normal renal function, followed by a dose adjusted for renal failure. Dosing adjustments of aminoglycosides should be assisted by measuring peak (drawn 1 hour after the start of a 30-minute IV infusion) and trough (drawn 30 minutes before next dose) serum levels.
[c] Rate or extent of absorption is decreased when the drug is taken with food.
[d] Dosage should not exceed that for adults.
[e] These drugs are generally avoided in children.
[f] Dose is based on TMP.
[g] The standard of care for dosing of this antibiotic for serious infections is complex and rapidly evolving (see discussion of individual drug for more information).
[h] Doses should be adjusted to achieve a steady-state trough concentration of 15–20 mg/L. When technically possible, it is preferable to adjust doses using AUC24/MIC ratio.

AUC24 = 24-hour area under the concentration-time curve; MIC = minimum inhibitory concentration; N/A = not applicable; TMP =

Drug

Adult Dosage

Pediatric (Age > 1 Month) Dosage

Dosage in Renal Failure[b] (Creatinine Clearance < 10 mL/minute)

Oral

Parenteral

Serious Infections

Oral

Parenteral

Aminoglycosides

N/A

15 mg/kg IV once/day

7.5 mg/kg every 12 hours

15 mg/kg IV once/day

7.5 mg/kg IV every 12 hours

N/A

5–7.5 mg/kg IV every 12 hours

1.5–2.5 mg/kg IV every 24–48 hours

N/A

5–7 mg/kg IV once/day

1.7 mg/kg IV every 8 hours

5–7 mg/kg IV once/day

N/A

1–2.5 mg/kg IV every 8 hours

0.34–0.51 mg/kg IV every 24–48 hours

N/A

1 mg/kg IV every 8 hours

N/A

1 mg/kg IV every 8 hours

Infectious disease consultation required for dosage

Dosage adjusted to achieve peak serum concentration of 3–4 mcg/mL (6.3–8.4 micromol/L) and trough concentration of < 1 mcg/mL (2.1 micromol/L)

1 g for 3 doses (eg, at 1, 2, and 11 PM on the day before surgery)

N/A

15 mg/kg every 4 hours for 2 days

25 mg/kg at 1, 2, and 11 PM on the day before surgery

N/A

For hepatic coma

1–3 g 4 times a day

N/A

0.6–1.75 g/m² every 6 hours

0.4–1.2 g/m² every 4 hours

N/A

For tuberculosis

N/A

15 mg/kg IM every 24 hours (maximum: 1.0 g/day) initially, then 1.0 g 2–3 times/week

N/A

20–40 mg/kg IM once/day

7.5 mg/kg IM every 72–96 hours (maximum: 1 g)

For synergy with a cell wall–active antibiotic to treat enterococcal endocarditis

N/A

7.5 mg/kg IM every 12 hours

N/A

5–7 mg/kg IV once/day

1.7 mg/kg IV every 8 hours

5–7 mg/kg IV once/day

1.7 mg/kg IV every 8 hours

N/A

1–2.5 mg/kg IV every 8 hours

0.34–0.51 mg/kg IV every 24–48 hours

Beta-lactams: Cephalosporins (1st generation)

0.5–1 g every 12 hours

N/A

15 mg/kg every 12 hours

N/A

0.5 g orally every 36 hours

N/A

1–2 g IV every 8 hours

2 g IV every 8 hours

N/A

16.6–33.3 mg/kg IV every 8 hours

1–2 g IV every 24–48 hours

0.25–0.5 g every 6 hours

N/A

6.25–12.5 mg/kg every 6 hours

8.0–16 mg/kg every 8 hours

N/A

0.25–0.5 g orally every 24–48 hours

Beta-lactams: Cephalosporins (2nd generation)

[c]

0.25–0.5 g every 8 hours

N/A

10–20 mg/kg every 12 hours

6.6–13.3 mg/kg every 8 hours

N/A

0.5 g orally every 12 hours

N/A

1–3 g IV every 12 hours

2–3 g IV every 12 hours

N/A

20–40 mg/kg IV every 12 hours

1–3 g IV every 48 hours

N/A

1 g IV every 8 hours to 2 g IV every 4 hours

2 g IV every 4 hours

3 g IV every 6 hours

N/A

27–33 mg/kg IV every 8 hours or, for severe infections, 25–40 mg/kg every 6 hours

0.5–1.0 g IV every 24–48 hours

0.25 g every 12 hours

0.5 g every 12–24 hours

N/A

15 mg/kg every 12 hours for otitis media

N/A

0.25 g orally every 12–24 hours

0.125–0.5 g every 12 hours

0.75–1.5 g IV every 6–8 hours

1.5 g IV every 6 hours

10–15 mg/kg suspension every 12 hours

For older children: 125–250-mg tablets every 12 hours

25–50 mg/kg IV every 8 hours

0.25–0.5 g orally every 24 hours

0.75 g IV every 24 hours

For meningitis

—

3 g IV every 8 hours

—

50–60 mg/kg IV every 6 hours

—

Beta-lactams: Cephalosporins (3rd generation)

N/A

1 g every 12 hours to 2 g IV every 4 hours

2 g IV every 4 hours

N/A

8.3–33.3 mg/kg IV every 4 hours

16.6–66.6 mg/kg every 6 hours

1–2 g IV every 24 hours

[d]

0.1–0.4 g every 12 hours

N/A

5 mg/kg every 12 hours

N/A

0.1–0.4 g orally every 24 hours

N/A

1 g IV every 12 hours to 2 g every 8 hours

2 g IV every 8 hours

N/A

25–50 mg/kg IV every 8 hours

0.5 g IV every 24–48 hours

N/A

2.5 g IV every 8 hours

N/A

0.94 g IV every 24–48 hours

Ceftibuten[c]

0.4 g every 24 hours

N/A

9 mg/kg once/day

N/A

0.1 g orally every 24 hours

N/A

1–2 g IV every 24 hours

2 g IV every 24 hours

N/A

50–75 mg/kg IV every 24 hours

25–37.5 mg/kg every 12 hours

Same as adult dose

For meningitis

N/A

2 g IV every 12 hours

N/A

50 mg/kg IV every 12 hours or 100 mg/kg every 24 hours (not to exceed 4 g/day)

Possibly a loading dose of 100 mg/kg IV (not to exceed 4 g) at the start of therapy

2 g IV every 12 hours

Beta-lactams: Cephalosporins (4th generation)

N/A

1–2 g IV every 8–12 hours

2 g IV every 8 hours

N/A

50 mg/kg IV every 8–12 hours

0.25–1 g IV every 24 hours

Beta-lactams: Cephalosporins (5th generation)

N/A

0.6 g IV every 12 hours

N/A

0.2 g IV every 12 hours

Novel cephalosporins

(1.5 g = ceftolozane 1 g + tazobactam 0.5 g)

N/A

1.5 g IV every 8 hours

N/A

0.75 g IV once, then 0.15 g IV every 8 hours

N/A

2 g IV every 8 hours

N/A

0.75 g IV every 12 hours

Beta-lactams: Penicillins

0.25–0.5 g every 8 hours

0.875 g every 12 hours

N/A

12.5–25 mg/kg every 12 hours

7–13 mg/kg every 8 hours

N/A

0.25–0.5 g orally every 24 hours

For endocarditis prophylaxis

2 g for 1 dose

N/A

50 mg/kg 1 hours before procedure

N/A

2 g orally for 1 dose

0.25–0.5 g every 8 hours

0.875 g every 12 hours

N/A

If > 40 kg: Adult dose

N/A

0.25–0.5 g orally every 24 hours

N/A

45 mg/kg every 12 hours

N/A

2 g every 12 hours

N/A

0.5–2.0 g IV every 4–6 hours

2 g IV every 4 hours

N/A

25–50 mg/kg IV every 6 hours

0.5–2.0 g IV every 12–24 hours

For meningitis

N/A

2 g IV every 4 hours

N/A

50–100 mg/kg IV every 6 hours

2 g IV every 12 hours

(3 g =+ 1 g sulbactam)

N/A

1.5–3.0 g IV every 6 hours

3 g IV every 6 hours

N/A

25–50 mg/kg IV every 6 hours

1.5–3.0 g IV every 24 hours

[c]

0.125–0.5 g every 6 hours

N/A

3.125–6.25 mg/kg every 6 hours

N/A

0.125–0.5 g orally every 6 hours

Rarely used

1–2 g IV every 4 hours

2 g IV every 4 hours

N/A

12.5–25 mg/kg IV every 6 hours

8.3–33.3 mg/kg every 4 hours

1–2 g IV every 4 hours

Rarely used

1–2 g IV every 4 hours

2 g IV every 4 hours

N/A

12.5–25 mg/kg IV every 6 hours

8.3–33.3 mg/kg IV every 4 hours

1–2 g IV every 4 hours

[c]

N/A

1–4 million units IV every 4–6 hours

4 million units IV every 4 hours

N/A

6,250–100,000 units/kg IV every 6 hours

4,166.6–66,666 units/kg IV every 4 hours

0.5–2 million units IV every 4–6 hours (maximum total daily dose: 6 million units/day)

0.25–0.5 g every 6–12 hours

N/A

6.25–12.5 mg/kg every 8 hours

N/A

(IM only)

For streptococcal pharyngitis

N/A

1.2 million units IM for 1 dose

N/A

25,000–50,000 units/kg IM as a single dose

If < 27 kg: 300,000–600,000 units as a single dose

If ≥ 27 kg: 0.9 million units as a single dose

1.2 million units IM for 1 dose

Prophylaxis for rheumatic fever

N/A

1.2 million units IM every 3–4 weeks

N/A

25,000–50,000 units/kg IM every 3–4 weeks

1.2 million units IM every 3–4 weeks

For early syphilis

N/A

2.4 million units IM for 1 dose

N/A

50,000 units/kg IM for 1 dose

2.4 million units IM for 1 dose

For late syphilis (excluding neurosyphilis)

N/A

2.4 million units IM/week for 3 weeks

N/A

50,000 units/kg IM in 3 doses 1 week apart

2.4 million units IM for 1 dose

(IM only)

N/A

0.3–0.6 million units IM every 12 hours

N/A

25,000–50,000 units/kg IM every 24 hours

12,500–25,000 units/kg IM every 12 hours

0.3 to 0.6 million units IM every 12 hours

Piperacillin (1.9 mEq sodium/g)

N/A

3 g IV every 4–6 hours

3 g IV every 4 hours

N/A

50–75 mg/kg IV every 6 hours

33.3–50 mg/kg IV every 4 hours

3–4 g IV every 12 hours

(2.25 g = 2.0 g piperacillin + 0.25 g

N/A

3.375 g IV every 6 hours

3.375 g IV infused over 4 hours every 8 hours or 4.5 g IV every 6 hours

N/A

80 mg/kg IV every 8 hours

2.25 g IV every 8 hours to 4.5 g IV every 12 hours

Beta-lactams: Monobactams

N/A

1–2 g IV every 6–12 hours

2 g IV every 6 hours

N/A

30–40 mg/kg IV every 6–8 hours

0.5 g IV every 8 hours

Beta-lactams: Carbapenems

N/A

1 g IV every 24 hours

N/A

0.5 g IV every 24 hours

Imipenem

N/A

0.5–1.0 g IV every 6 hours

1 g IV every 6 hours

N/A

For infants 4 weeks to 3 months: 25 mg/kg IV every 6 hours

For children >3 months: 15–25 mg/kg IV every 6 hours

0.125–0.25 g IV every 12 hours (may increase risk of seizures)

N/A

1 g IV every 8 hours

2 g IV every 8 hours

N/A

20–40 mg/kg IV every 8 hours

0.5 g IV every 24 hours

For meningitis

N/A

2g IV every 8 hours

2 g IV every 8 hours

N/A

40 mg/kg IV every 8 hours

1 g IV every 24 hours

N/A

4 g IV every 8 hours

N/A

1g IV every 12 hours

N/A

0.5 g IV every 8 hours

N/A

0.25 g IV every 24 hours

Fluoroquinolones[e]

0.5–0.75 g every 12 hours

0.2–0.4 g IV every 8–12 hours

0.4 g IV every 8 hours

10–15 mg/kg IV every 12 hours (in select circumstances)

0.5–0.75 g orally every 24 hours

0.2–0.4 g IV every 24 hours

Extended-release for uncomplicated cystitis

0.5 g every 24 hours for 3 days

N/A

450 mg every 12 hours

300 mg IV every 12 hours

N/A

320 mg every 24 hours

N/A

160 mg orally every 24 hours

0.25–0.75 g every 24 hours

0.25–0.75 IV g every 24 hours

0.75 g IV every 24 hours

N/A

0.25–0.5 g orally or IV every 48 hours

0.4 g every 24 hours

0.4 g IV every 24 hours

N/A

0.4 g every 24 hours orally or IV

Norfloxacin[c]

0.4 g every 12 hours

N/A

0.4 g orally every 24 hours

0.2–0.4 g every 12 hours

0.4 g IV every 12 hours

0.2–0.4 g IV every 12 hours

N/A

0.1–0.2 g orally or IV every 24 hours

Macrolides

0.5 g on day 1, then 0.25 g every 24 hours for 4 days

0.5 g IV every 24 hours

—

N/A

0.5 g orally on day 1, then 0.25 g orally every 24 hours for 4 days or 0.5 g IV every 24 hours

For nongonococcal cervicitis and urethritis

1 g for 1 dose

N/A

For traveler’s diarrhea

1 g for 1 dose

N/A

5–10 mg/kg for 1 dose

N/A

For tonsillitis or pharyngitis

N/A

12 mg/kg for 5 days

N/A

For otitis media or community-acquired pneumonia

N/A

10 mg/kg on day 1, then 5 mg/kg once/day on days 2–5

N/A

0.25–0.5 g every 12 hours

Extended-release: 1 g every 24 hours

N/A

7.5 mg/kg every 12 hours

N/A

0.25–0.5 g orally every 24 hours

[c]

0.25–0.5 g every 6 hours

N/A

10–16.6 mg/kg every 8 hours

7.5–12.5 mg/kg every 6 hours

N/A

0.25 g orally every 6 hours

For gastrointestinal preoperative bowel preparation

1 g for 3 doses

N/A

20 mg/kg for 3 doses

N/A

0.5–1 g IV every 6 hours

1 g IV every 6 hours

N/A

3.75–5.0 mg/kg IV every 6 hours

0.5 g IV every 6 hours

N/A

0.5–1 g IV every 6 hours

1 g IV every 6 hours

N/A

3.75–5.0 mg/kg IV every 6 hours

0.5 g IV every 6 hours

for Clostridioides difficile (formerly Clostridium difficile) infection

200 mg 2 times a day for 10 days

N/A

Weight-based dosing for infants ≥ 6 months and children:

16 mg/kg 2 times a day for 10 days; maximum: 200 mg/dose

Fixed dosing for infants ≥ 6 months, children, and adolescents:

4 to < 7 kg, oral suspension: 80 mg 2 times a day for 10 days
7 to < 9 kg, oral suspension: 120 mg 2 times a day for 10 days
9 to < 12.5 kg, oral suspension: 160 mg 2 times a day for 10 days
≥ 12.5 kg, oral suspension, tablets: 200 mg 2 times a day for 10 days

N/A

N/A (minimal systemic absorption)

Sulfonamides and

Sulfisoxazole

1.0 g every 6 hours

25 mg/kg IV every 6 hours (not available in the US)

N/A

30–37.5 mg/kg every 6 hours

20–25 mg/kg every 4 hours

N/A

1 g orally every 12–24 hours

Sulfamethizole

0.5–1 g every 6–8 hours

N/A

7.5–11.25 mg/kg every 6 hours

N/A

Sulfamethoxazole

1 g every 8–12 hours

N/A

25–30 mg/kg every 12 hours

N/A

1 g orally every 24 hours

0.1 g every 12 hours

0.2 g every 24 hours

N/A

2 mg/kg every 12 hours for 10 days for urinary tract infection

N/A

0.1 g orally every 24 hours

[f]

0.16/0.8 g every 12 hours

3–5 mg TMP/kg IV every 6–8 hours

5 mg TMP/kg IV every 6 hours

3–6 mg TMP/kg every 12 hours

3–6 mg TMP/kg IV every 12 hours

Not recommended if other alternatives are available

For Pneumocystis jirovecii pneumonia[f]

0.32/1.6 g every 8 hours for 21 days

5 mg TMP/kg IV every 8 hours for 21 days

5 mg TMP/kg IV every 6–8 hours

5–6.6 mg TMP/kg every 8 hours

3.75–5 mg TMP/kg every 6 hours

5–6.6 mg TMP/kg IV every 8 hours

3.75–5 mg TMP/kg IV every 6 hours

If essential, 5 mg TMP/kg IV every 24 hours

1.25 mg TMP/kg IV every 6 hours

Tetracyclines

0.1 g every 12 hours

0.1 g IV every 12 hours

0.1 mg IV every 12 hours

Age > 8 years: 2–4 mg/kg every 24 hours

1–2 mg/kg every 12 hours

Age > 8 years: 2–4 mg/kg IV every 24 hours

1–2 mg/kg IV every 12 hours

0.1 g IV or orally every 12 hours

N/A

1 mg/kg IV every 12 hours

Same as adult dose

N/A

Same as adult dose

0.1 g every 12 hours

0.1 g IV every 12 hours

N/A

0.1 g IV or orally every 12 hours

0.45 g every 24 hours x 2 doses, then 0.3 g every 24 hours

0.2 g IV on day 1, then 0.1 g IV every 24 hours

Same as adult dose

N/A

Same as adult dose

[c]

0.25–0.5 g every 6 hours

N/A

Age > 8 years: 6.25–12.5 mg/kg every 6 hours

N/A

100 mg, then 50 mg (25 mg for severe hepatic dysfunction) IV every 12 hours

Same as adult dose[g]

N/A

Same as adult dose

Others

0.15–0.45 g every 6 hours

0.6 g IV every 6 hours to 0.9 IV g every 8 hours

0.9 g IV every 8 hours

2.6–6.6 mg/kg every 8 hours

2–5 mg/kg every 6 hours

6.6–13.2 mg/kg IV every 8 hours

5–10 mg/kg IV every 6 hours

0.15–0.45 g orally every 6 hours

0.6–0.9 g IV every 6–8 hours

0.25–1 g every 6 hours

0.25–1.0 g IV every 6 hours

1 g IV every 6 hours

N/A

12.5–18.75 mg/kg IV every 6 hours

0.25–1.0 g IV every 6 hours

For meningitis

N/A

12.5 mg/kg every 6 hours (maximum: 4 g/day)

12.5 mg/kg IV every 6 hours (maximum: 4 g/day)

N/A

18.75–25 mg/kg IV every 6 hours

12.5 mg/kg IV every 6 hours (maximum: 4 g/day)

Colistin (polymyxin E)

N/A

2.5–5 mg/kg/day IV in 2–4 doses

2.5–5 mg/kg/day IV in 2–4 doses[g]

N/A

1.5 mg/kg every 36 hours

N/A

1500 mg as a single dose or 1000 mg once, followed by a 500-mg dose 1 week later

N/A

1125 mg as a single dose or 750 mg once, followed by a 375-mg dose 1 week later

N/A

4–6 mg/kg IV every 24 hours

8–10 mg/kg IV every 24 hours[g]

N/A

4–6 mg/kg IV every 48 hours

0.2 g every 12 hours

N/A

0.2 g orally every 12 hours

A single dose of 3 g in 3–4 oz of water

Not available in the US

N/A

A single dose of 3 g in 3–4 oz of water

0.6 g every 12 hours

0.15 g IV every 12 hours

Same as adult dose

N/A

Same as adult dose

0.6 g every 12 hours

0.6 g IV every 12 hours

10 mg/kg every 8 hours

10 mg/kg IV every 8 hours

0.6 g IV or orally every 12 hours

For anaerobic infection

7.5 mg/kg every 6 hours (not to exceed 4 g/day)

7.5 mg/kg IV every 6 hours (not to exceed 4 g/day)

7.5 mg/kg every 6 hours

7.5 mg/kg IV every 6 hours

3.75 mg/kg IV or orally every 6 hours (not to exceed 2 g/day)

For trichomoniasis

2 g for 1 dose

0.5 g every 12 hours for 7 days

N/A

For Clostridioides difficile–induced diarrhea (pseudomembranous colitis)

0.5 g every 6–8 hours for 10–14 days

500 mg IV every 6–8 hours

500 mg IV every 6 hours

7.5 mg/kg every 8 hours

7.5 mg/kg IV every 6 hours

250 mg orally or IV every 8 hours

For amebiasis

11.6–16.6 mg/kg every 8 hours for 7–10 days

11.6–16.6 mg/kg IV every 8 hours for 7–10 days

N/A

For giardiasis

0.25 g every 6–8 hours for 5–7 days

N/A

5 mg/kg every 6–8 hours for 5 days

N/A

50–100 mg every 6 hours

N/A

1.25–1.75 mg/kg every 6 hours

N/A

Not recommended

100 mg every 12 hours

N/A

1200 mg as a single dose

N/A

1200 mg as a single dose

Quinupristin/dalfopristin

N/A

7.5 mg/kg IV every 8–12 hours

7.5 mg/kg IV every 8 hours

N/A

7.5 mg/kg IV every 12 hours for complicated skin or skin structure infection

7.5 mg/kg every 8 hours for serious infections

7.5 mg/kg IV every 8–12 hours

For tuberculosis (as part of a 3- or 4-drug regimen)

0.6 g every 24 hours

0.6 g IV every 24 hours

N/A

5–10 mg/kg every 12 hours

10–20 mg/kg every 24 hours

10–20 mg/kg IV every 24 hours

0.3–0.6 g IV or orally every 24 hours

For meningococcal exposure

0.6 g every 12 hours for 4 doses

N/A

Age ≥ 1 month: 10 mg/kg every 12 hours for 2 days

Age < 1 month: 5 mg/kg every 12 hours for 2 days

N/A

0.6 g orally every 12 hours for 4 doses

For Haemophilus influenzae exposure

20 mg/kg every 24 hours for 4 days (not to exceed 600 mg every 24 hours)

N/A

20 mg/kg every 24 hours for 4 days

Age < 1 month: 10 mg/kg every 24 hours for 4 days

N/A

20 mg/kg every 24 hours for 4 days (not to exceed 600 mg every 24 hours)

0.3 g every 8 hours

0.6–0.9 g every 24 hours

0.3 g IV every 8 hours

0.6–0.9 g IV every 24 hours

0.3 g IV every 8 hours

0.6–0.9 g IV every 24 hours

—

0.3 g IV or orally every 8 hours

0.6–0.9 g IV or orally every 24 hours

For pulmonary tuberculosis (as part of a 3- or 4- drug regimen)

Initial phase (2 months): 0.6 g twice/week

Continuation phase (4 months): 0.6 g once/week

N/A

0.9 g once/week (3 months)

N/A

200 mg every 24 hours

200 mg IV every 24 hours

N/A

200 mg orally or IV every 24 hours

N/A

10 mg/kg IV every 24 hours

N/A

125 mg every 6 hours (only effective for C. difficile–induced diarrhea)

15 mg/kg IV every 12 hours (often 1 g every 12)

25 mg/kg once, then 15–20 mg/kg IV every 8–12 hours[g]

N/A

13 mg/kg IV every 8 hours

10 mg/kg IV every 6 hours

0.5–1.0 g IV every week[h]

For meningitis[i]

N/A

15–20 mg/kg IV every 8–12 hours[h]

N/A

15 mg/kg IV every 6 hours

15 mg/kg IV every week[h]

[b] Initial loading dose should be equivalent to the usual dose for patients with normal renal function, followed by a dose adjusted for renal failure. Dosing adjustments of aminoglycosides should be assisted by measuring peak (drawn 1 hour after the start of a 30-minute IV infusion) and trough (drawn 30 minutes before next dose) serum levels.

[c] Rate or extent of absorption is decreased when the drug is taken with food.

[d] Dosage should not exceed that for adults.

[e] These drugs are generally avoided in children.

[f] Dose is based on TMP.

[g] The standard of care for dosing of this antibiotic for serious infections is complex and rapidly evolving (see discussion of individual drug for more information).

[h] Doses should be adjusted to achieve a steady-state trough concentration of 15–20 mg/L. When technically possible, it is preferable to adjust doses using AUC24/MIC ratio.

AUC24 = 24-hour area under the concentration-time curve; MIC = minimum inhibitory concentration; N/A = not applicable; TMP =