POSFREA
Clinical safety rating: caution
Comprehensive clinical and safety monograph for POSFREA (POSFREA).
POSFREA is a carbapenem-class antibiotic that inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), leading to cell death.
| Metabolism | POSFREA is not significantly metabolized; it is primarily excreted unchanged in the urine. |
| Excretion | Renal (95%) as unchanged drug; biliary/fecal (5%). |
| Half-life | 12 hours (range 10-14) in healthy adults; prolonged to 24-48 hours in severe renal impairment (CrCl <30 mL/min). |
| Protein binding | 98%, primarily to albumin. |
| Volume of Distribution | 0.25 L/kg (0.2-0.3), indicating minimal tissue distribution (confined to plasma and extracellular fluid). |
| Bioavailability | Oral: 75% (range 60-85%); IV: 100%. |
| Onset of Action | Oral: 30-60 minutes; IV: immediate (within 5 minutes). |
| Duration of Action | Oral: 8-12 hours; IV: 6-8 hours. Duration correlates with half-life. |
| Molecular Weight | 450.52 |
IV 4 mg/kg once daily; infused over 90 minutes.
| Dosage form | SOLUTION |
| Renal impairment | GFR >60 mL/min: No adjustment. GFR 30-60: 3 mg/kg daily. GFR <30: 2 mg/kg daily. Hemodialysis: 2 mg/kg post-dialysis. |
| Liver impairment | Child-Pugh A: No adjustment. Child-Pugh B: 3 mg/kg daily. Child-Pugh C: 2 mg/kg daily. |
| Pediatric use | Children ≥2 years: IV 4 mg/kg once daily; max 200 mg. Infants <2 years: Not established. |
| Geriatric use | Start at lower end of dosing range (3 mg/kg) due to age-related renal decline; monitor renal function. |
| 1st trimester | Insufficient human data; animal studies show fetal risk. Avoid use unless benefit outweighs risk. |
| 2nd trimester | May cause fetal harm based on animal data. Use only if clearly needed. |
| 3rd trimester | Risk of neonatal complications (e.g., hypotension, renal dysfunction). Avoid near term. |
Clinical note
Comprehensive clinical and safety monograph for POSFREA (POSFREA).
| Placental transfer | Crosses placenta (documented in animal models); human transfer presumed. |
| Breastfeeding | Excreted in breast milk in small amounts; potential for infant adverse effects. Consider alternatives. |
| Lactation Rating |
■ FDA Black Box Warning
There is no FDA black box warning for POSFREA.
| Serious Effects |
Hypersensitivity to POSFREA or any excipientSevere hepatic impairment (Child-Pugh class C)Concurrent use with strong CYP3A4 inducers
| Precautions | Hypersensitivity reactions including anaphylaxis, Clostridioides difficile-associated diarrhea (CDAD), Seizures and other CNS adverse reactions, Reduced efficacy in patients with renal impairment |
| Food/Dietary | Avoid grapefruit and grapefruit juice as they may increase blood levels of amiodarone and risk of toxicity. No other significant food interactions. |
| Clinical Pearls |
Loading safety data…
| L4 |
| Teratogenic Risk | POSFREA is not a recognized drug. No teratogenic data available. |
| Fetal Monitoring | Not applicable. |
| Fertility Effects | No data. |
| POSFREA is a fixed-dose combination of amiodarone and esmolol used for acute rate control in atrial fibrillation with rapid ventricular response. Monitor for hypotension and bradycardia; avoid in patients with pre-existing bradycardia or heart block. Administer via slow IV push over 10 minutes to minimize infusion-related hypotension. ECG monitoring required during administration. |
| Patient Advice | This medication is given intravenously to rapidly control your heart rate. · You will be closely monitored for changes in heart rate and blood pressure during treatment. · Report any symptoms of dizziness, lightheadedness, or chest pain immediately. · Avoid driving or operating machinery until you know how this medication affects you. · Do not consume grapefruit or grapefruit juice while on this medication. |