VELOSEF '125'
Clinical safety rating: caution
Comprehensive clinical and safety monograph for VELOSEF '125' (VELOSEF '125').
Cephalexin is a first-generation cephalosporin antibiotic that inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), inhibiting peptidoglycan cross-linking, leading to cell lysis.
| Metabolism | Primarily excreted unchanged in urine via glomerular filtration and tubular secretion; minor hepatic metabolism (less than 10%) via deacetylation. |
| Excretion | Renal: 80-90% unchanged via glomerular filtration and tubular secretion; biliary/fecal: <5% |
| Half-life | Terminal elimination half-life: 0.5-1.0 hour (normal renal function); prolonged to 10-20 hours in severe renal impairment (CrCl <10 mL/min) |
| Protein binding | 10-15% bound to serum albumin |
| Volume of Distribution | 0.2-0.4 L/kg (indicates distribution primarily in extracellular fluid) |
| Bioavailability | Oral: 90-95% (capsule); IM: 80-90% (relative to IV) |
| Onset of Action | Oral: 30-60 minutes; Intramuscular: 15-30 minutes; Intravenous: immediate |
| Duration of Action | 6-8 hours (dose-dependent; extended with probenecid co-administration) |
| Molecular Weight | 363.4 |
500 mg orally every 6 hours for uncomplicated infections; 1 g orally every 6 hours for more severe infections.
| Dosage form | FOR SUSPENSION |
| Renal impairment | CrCl 50-80 mL/min: 500 mg every 8 hours; CrCl 10-49 mL/min: 500 mg every 12 hours; CrCl <10 mL/min: 500 mg every 24 hours. |
| Liver impairment | No clinically significant adjustment required; no Child-Pugh based modifications established. |
| Pediatric use | 25-50 mg/kg/day in 4 divided doses every 6 hours; maximum 1 g/day. |
| Geriatric use | No specific adjustment based on age alone; adjust dose for renal function per CrCl. |
| 1st trimester | Generally considered safe; no known teratogenic effects in animal studies. |
| 2nd trimester | Safe; monitor for maternal allergic reactions. |
| 3rd trimester | Safe; potential risk of neonatal sensitization if maternal hypersensitivity occurs. |
Clinical note
Comprehensive clinical and safety monograph for VELOSEF '125' (VELOSEF '125').
| Placental transfer | Crosses placenta; fetal serum levels are low, approximately 10-15% of maternal levels. |
| Breastfeeding | Excreted into breast milk in low concentrations; unlikely to cause adverse effects in nursing infants. Use with caution in infants with glucose-6-phosphate dehydrogenase deficiency. |
| Lactation Rating |
■ FDA Black Box Warning
No FDA boxed warning.
| Serious Effects |
Hypersensitivity to cephalosporins or other beta-lactam antibioticsSevere hypersensitivity to penicillins (cross-sensitivity)
| Precautions | Serious hypersensitivity reactions (anaphylaxis) possible, especially in penicillin-allergic patients, Clostridioides difficile-associated diarrhea (CDAD) may occur, Renal impairment requires dose adjustment (creatinine clearance <30 mL/min), Prolonged use may result in overgrowth of nonsusceptible organisms, Positive direct Coombs' test may develop |
| Food/Dietary | Concurrent administration with food may decrease the rate but not extent of absorption; take with meals to minimize gastrointestinal discomfort. Avoid alcohol during therapy and for 72 hours after completion to reduce risk of disulfiram-like reaction (reported with some cephalosporins). Avoid concurrent use of antacids or iron supplements as they can bind cephalosporins and reduce absorption; separate by at least 2 hours. |
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| Teratogenic Risk | Cephalosporins (FDA category B). No fetal risk observed in animal studies; no adequate human studies. Use only if clearly needed. No known teratogenicity in any trimester. |
| Fetal Monitoring | Monitor maternal renal function, CBC, and stool for signs of superinfection or C. difficile colitis. No specific fetal monitoring beyond routine antenatal care. |
| Fertility Effects | No known adverse effects on human fertility based on animal data and limited human experience; no specific fertility studies. |
| Clinical Pearls | Velosef '125' (cephradine 125 mg) is a first-generation cephalosporin with activity against Gram-positive cocci (except MRSA) and some Gram-negative rods. It is stable to staphylococcal penicillinase. Peak serum levels are achieved 1 hour after oral administration; dose adjustment required in renal impairment (CrCl <30 mL/min). Administer with food to reduce GI upset; avoid concurrent use with bacteriostatic antibiotics (e.g., tetracyclines) as antagonism may occur. Cross-allergenicity with penicillins occurs in ~5-10% of patients; use with caution in penicillin-allergic patients. For pediatric strep pharyngitis, a 10-day course is recommended to prevent rheumatic fever. Not effective against Pseudomonas or Enterococcus. |
| Patient Advice | Take this medication exactly as prescribed; do not skip doses or stop early even if you feel better. · Complete the full course of therapy (usually 7–14 days) to prevent infection recurrence and antibiotic resistance. · Take with food or milk if stomach upset occurs; avoid taking with antacids or iron supplements within 2 hours. · Notify your doctor if you develop rash, diarrhea, or signs of allergic reaction (hives, trouble breathing). · Do not use this medicine if you have had a severe allergic reaction to cephalosporins or penicillins. |