PRIMAXIN
Combination product
Pronunciation: i-mi-PEN-em and sye-la-STAT-in
Combination of Imipenem and Cilastatin.
Each component keeps its own pharmacology page; the combination itself adds no new mechanism.
Components (2)
FDA label
Read the full label on DailyMed ↗
| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Serious infections caused by susceptible bacteria (LRTI, UTI, intra-abdominal, gynecologic, septicemia, bone/joint, skin, endocarditis) | Adults, CrCl ≥90 mL/min | 500 mg every 6 hours or 1000 mg every 8 hours | 500 mg q6h or 1000 mg q8h (susceptible); 1000 mg q6h (intermediate susceptibility) | 4 g/day |
| Serious non-CNS infections caused by susceptible bacteria | Pediatric ≥3 months (non-CNS) | 15-25 mg/kg every 6 hours | 15-25 mg/kg q6h | 4 g/day |
Renal Dose reduction required for CrCl <90 mL/min (per label tables); CrCl <15 should not receive unless hemodialysis instituted within 48 hours; increased seizure risk at CrCl <30
Hepatic Undefined
Maximum total daily dose 4 g/day
Instructions
- Administer by intravenous infusion only (500 mg over 20-30 min; 1000 mg over 40-60 min); slow rate if nausea occurs
- Reconstitute and dilute before administration; do not mix with or physically add to other antibacterials
- Not recommended in pediatric patients with CNS infections (seizure risk) or in pediatric patients <30 kg with renal impairment
Available strengths
- inj 250/250, 500/500 mg
Cautions
- Serious/fatal hypersensitivity (anaphylactic) reactions with beta-lactams
- Seizure potential (especially with CNS disorders or renal impairment)
- Increased seizure risk with valproic acid/divalproex (reduces valproate levels) — concomitant use generally not recommended
- Clostridioides difficile-associated diarrhea
- Development of drug-resistant bacteria
Adverse reactions
- Phlebitis/thrombophlebitis
- Nausea
- Diarrhea
- Vomiting
- Rash
- Injection-site pain
- Fever
- Hypotension
- Seizures
- Pruritus
Pregnancy Insufficient human data; animal studies showed embryonic loss in monkeys at doses similar to human dose
Lactation Insufficient data on presence in human milk or effects on breastfed child
Cost
PRIMAXIN
| Strength | #/mo | generic $/unit | CostPlus | |
|---|---|---|---|---|
| 250/250 mg | inj | per unit | not offered | |
| 500/500 mg | inj | per unit | not offered |
NADAC is a voluntary CMS survey of what retail community pharmacies pay for the drugs they stock. PRIMAXIN is administered under clinical supervision and dispensed outside retail pharmacies, so it rarely appears on surveyed invoices.
Other forms: Imipenem (in PRIMAXIN)
Part D rank #886.