Piperacillin
in ZOSYN
Pronunciation: pi-PER-a-sil-in
What it isExtended-spectrum penicillin, given with tazobactam; hospital-acquired and intra-abdominal infection.
Why this oneVery broad cover including Pseudomonas and anaerobes in one agent.
What limits itAcute kidney injury when combined with vancomycin. It causes falsely positive galactomannan; no MRSA cover.
FDA label
Read the full label on DailyMed ↗
| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Serious infections (septicemia, nosocomial pneumonia, intra-abdominal, gynecologic, skin/soft-tissue) | Adult | 12-18 g/day IV (200-300 mg/kg/d) divided q4-6h | 12-18 g/day IV | 24 g/day |
| Complicated urinary tract infection | Adult | 8-16 g/day IV (125-200 mg/kg/d) divided q6-8h | 8-16 g/day IV | 24 g/day |
| Uncomplicated UTI; most community-acquired pneumonia | Adult | 6-8 g/day IM or IV (100-125 mg/kg/d) divided q6-12h | 6-8 g/day | 24 g/day |
| Uncomplicated gonorrhea | Adult | 2 g IM once (with probenecid 1 g PO 30 min prior) | Single dose | 2 g x1 |
| Surgical prophylaxis (intra-abdominal, hysterectomy, cesarean) | Adult | 2 g IV just prior to surgery (cesarean: after cord clamped), then 2-3 procedure-specific doses | Stop within 24 h post-op |
Renal CrCl 20-40: serious infections 12 g/d (4 g q8h), complicated UTI 9 g/d (3 g q8h); CrCl <20: serious 8 g/d (4 g q12h), UTIs 6 g/d (3 g q12h); hemodialysis: max 6 g/d (2 g q8h) plus 1 g after each dialysis
Hepatic Undefined (in combined renal failure + hepatic insufficiency, guide dosing by serum piperacillin levels)
Usual course 7-10 days (gynecologic 3-10 days); pediatric <12 yr dosing not established
Instructions
- IV: 20-30 min infusion (preferred for serious infections) or slow 3-5 min injection
- IM: limit to 2 g per injection site (upper outer gluteal preferred)
- Do not mix with an aminoglycoside in the same syringe/infusion bottle (inactivates aminoglycoside)
- Treat >=48-72 h after patient becomes asymptomatic; S. pyogenes: >=10 days
- Contains 1.85 mEq sodium per gram — consider in salt-restricted patients
Available strengths
- inj 2, 3, 4 g
Contraindications
- History of allergic reactions to any beta-lactams, including penicillins and/or cephalosporins
Cautions
- Serious, occasionally fatal anaphylactic/anaphylactoid reactions — inquire about penicillin/cephalosporin/allergen history
- C. difficile-associated diarrhea (mild to fatal colitis)
- Bleeding manifestations with coagulation abnormalities, more likely in renal failure — discontinue if they occur
- Neuromuscular excitability or convulsions with higher-than-recommended IV doses
- Hypokalemia — monitor electrolytes in patients with low potassium reserves or on cytotoxics/diuretics
- Leukopenia/neutropenia with prolonged therapy
- Increased fever and rash in cystic fibrosis patients
Adverse reactions
- Local: thrombophlebitis (4%), injection-site pain/erythema/induration (2%)
- Diarrhea/loose stools (2%); nausea, vomiting, LFT elevations
- Rash (1%), pruritus; erythema multiforme, SJS/TEN reported
- Hypersensitivity incl. anaphylaxis
- Renal: elevated BUN/creatinine, interstitial nephritis, renal failure
- Headache, dizziness, seizures
- Cytopenias, eosinophilia, prolonged bleeding time; hypokalemia
- Fever, superinfection incl. candidiasis
Pregnancy Category B — animal studies show no fetal harm; no adequate human studies; use only if clearly needed.
Lactation Excreted in low concentrations in human milk; use caution in nursing mothers.
Cost
| Strength | #/mo | generic $/unit | CostPlus | |
|---|---|---|---|---|
| 2 g | inj | per unit | not offered | |
| 3 g | inj | per unit | not offered | |
| 4 g | inj | per unit | not offered |
Available combined with: piperacillin / tazobactam
Generic entry2009
NO BOXED WARNINGS
Principal riskNephrotoxicity with vancomycin; false-positive galactomannan
Classes and tags
Clinical profile
Legacy pregnancy categoryUnknown / historical label unavailable
Defining liabilitySerious infection and infusion/injection reactions; immune complications vary by molecular target.