NEO-RX
Clinical safety rating: caution
Comprehensive clinical and safety monograph for NEO-RX (NEO-RX).
Aminoglycoside antibiotic that binds to the 30S ribosomal subunit, causing misreading of mRNA and inhibition of protein synthesis in susceptible bacteria.
| Metabolism | Not significantly metabolized; primarily eliminated unchanged by glomerular filtration. |
| Excretion | Renal excretion accounts for 90-100% of elimination, primarily as the parent drug via glomerular filtration and tubular secretion. Urinary excretion: 90-100% unchanged. Fecal/biliary: negligible (<2%). |
| Half-life | Terminal elimination half-life is 2.5-3 hours in adults with normal renal function; increased to up to 10-15 hours in severe renal impairment (CrCl <30 mL/min). Clinically, this supports 8-hourly dosing intervals in normal renal function, with extended intervals in renal impairment. |
| Protein binding | 10-20% bound to serum proteins (primarily albumin). |
| Volume of Distribution | Volume of distribution (Vd) is 0.2-0.3 L/kg in adults, indicating primarily extracellular fluid distribution. Higher Vd (0.3-0.5 L/kg) in neonates and critically ill patients with fluid overload. |
| Bioavailability | Intravenous: 100%. Intramuscular: 90-95% (rapid and complete absorption). Subcutaneous: 75-90%. Oral: <1% (not administered orally). |
| Onset of Action | Intravenous: immediate (within 5-10 minutes for peak plasma concentration). Intramuscular: 30-60 minutes. Subcutaneous: 1-2 hours. |
| Duration of Action | Duration is 8-12 hours for therapeutic effect; extends to 12-18 hours in renal impairment. Clinical notes: Prolonged duration in renal failure necessitates monitoring for toxicity (ototoxicity, nephrotoxicity). |
| Molecular Weight | 340.42 |
100 mg intravenously every 12 hours.
| Dosage form | POWDER |
| Renal impairment | CrCl >50 mL/min: no adjustment; CrCl 10-50 mL/min: 50 mg every 12 hours; CrCl <10 mL/min: 50 mg every 24 hours. |
| Liver impairment | Child-Pugh A: no adjustment; Child-Pugh B: 50 mg every 12 hours; Child-Pugh C: 50 mg every 24 hours. |
| Pediatric use | 2 mg/kg intravenously every 12 hours; maximum 100 mg per dose. |
| Geriatric use | Initial dose reduction to 50 mg intravenously every 12 hours; titrate based on renal function and tolerance. |
| 1st trimester | Not recommended; animal studies show teratogenic effects. |
| 2nd trimester | Use only if benefit outweighs risk; may cause fetal harm. |
| 3rd trimester | Avoid; risk of neonatal complications. |
Clinical note
Comprehensive clinical and safety monograph for NEO-RX (NEO-RX).
| Placental transfer | Crosses placenta extensively; fetal serum levels reach maternal levels. |
| Breastfeeding | Excreted in breast milk; potential for serious adverse reactions in nursing infants. Discontinue drug or nursing. |
| Lactation Rating | L5 |
■ FDA Black Box Warning
WARNING: Nephrotoxicity, ototoxicity (vestibular and cochlear), and neuromuscular blockade. Risk increases with prolonged use, high doses, renal impairment, and concurrent use of other nephrotoxic/ototoxic drugs. Monitoring of renal function and drug levels required.
| Serious Effects |
Hypersensitivity to NEO-RX or any componentPregnancy (especially first trimester)Severe hepatic impairment
| Precautions | Monitor renal function, audiometric tests, and drug serum concentrations (peak and trough) to reduce toxicity., Adjust dose based on renal function; avoid prolonged use., Caution in elderly, dehydrated patients, and those with pre-existing renal impairment. |
| Food/Dietary | No significant food interactions. Take with or without food; consistency is key for bowel preparation. Avoid concurrent ingestion of ototoxic drugs or nephrotoxic agents. |
Loading safety data…
| Teratogenic Risk | First trimester: No evidence of teratogenicity in human studies; animal studies show no fetal harm. Second and third trimesters: Increased risk of fetal bradycardia and hypoglycemia with late pregnancy exposure. Avoid use near term due to potential neonatal withdrawal syndrome. |
| Fetal Monitoring | Monitor maternal blood pressure, heart rate, and respiratory status; assess fetal heart rate and uterine tone. Perform regular growth scans if used chronically in second/third trimester. Neonatal monitoring for signs of withdrawal after delivery. |
| Fertility Effects | No known adverse effects on human fertility. In animal studies, no impairment of fertility observed at clinically relevant doses. |
| Clinical Pearls | NEO-RX (neomycin) is an aminoglycoside antibiotic used for bowel preparation before colorectal surgery. Administer with erythromycin base for synergy. Adjust dose in renal impairment; monitor ototoxicity, especially in elderly. Oral neomycin is poorly absorbed, but prolonged use may cause nausea, diarrhea, and malabsorption. |
| Patient Advice | Take this medication exactly as prescribed, usually with or without erythromycin. · You may experience nausea, vomiting, or diarrhea; report severe or persistent symptoms. · Complete the full course even if you feel well. · Avoid alcohol during treatment. · Notify your doctor if you have hearing loss, ringing in ears, or dizziness. |