VELOSEF '500'
Clinical safety rating: caution
Comprehensive clinical and safety monograph for VELOSEF '500' (VELOSEF '500').
Cephradine inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), inhibiting the final transpeptidation step of peptidoglycan synthesis, leading to cell lysis and death. It is a first-generation cephalosporin with bactericidal activity.
| Metabolism | Cephradine is not extensively metabolized; it is primarily excreted unchanged in urine via glomerular filtration and tubular secretion. A small amount may be metabolized via hydrolysis of the beta-lactam ring. No significant hepatic metabolism. |
| Excretion | Renal excretion of unchanged drug: >90% (glomerular filtration and tubular secretion); biliary/fecal: <1% |
| Half-life | Terminal elimination half-life: 1.2 hours in adults with normal renal function; prolonged to 8-15 hours in severe renal impairment (CrCl <10 mL/min); clinical context: dosing interval adjustment required for renal impairment |
| Protein binding | 10-15% bound to plasma proteins (primarily albumin) |
| Volume of Distribution | 0.2-0.3 L/kg; clinical meaning: distributes primarily into extracellular fluid; low Vd consistent with limited tissue penetration |
| Bioavailability | Oral: 90-95% (well absorbed); intramuscular: 100% (complete absorption) |
| Onset of Action | Oral: 30-60 minutes (therapeutic serum levels); intramuscular: 15-30 minutes; intravenous: immediate |
| Duration of Action | 6-12 hours (depending on renal function and dose); clinical note: requires twice-daily or thrice-daily dosing in normal renal function |
500 mg orally every 6 hours for 10 days.
| Dosage form | CAPSULE |
| Renal impairment | For CrCl 20-30 mL/min: 500 mg every 12 hours. For CrCl 10-19 mL/min: 500 mg every 24 hours. For CrCl <10 mL/min: 500 mg every 36 hours. Hemodialysis: 500 mg after dialysis. |
| Liver impairment | No dose adjustment recommended for hepatic impairment as drug is renally excreted. |
| Pediatric use | Children >1 month: 25-50 mg/kg/day in divided doses every 6 hours. Maximum 500 mg/dose. |
| Geriatric use | No specific dose adjustment; monitor renal function and reduce dose per renal adjustment guidelines. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for VELOSEF '500' (VELOSEF '500').
| Breastfeeding | Cefradine is excreted into breast milk in low concentrations (M/P ratio approximately 0.2). Amount ingested by infant is subtherapeutic. Generally considered compatible with breastfeeding; however, monitor infant for potential gastrointestinal disturbances (e.g., diarrhea, candidiasis). |
| Teratogenic Risk | Cefradine (Velosef) is classified as FDA Pregnancy Category B. Animal studies have not demonstrated fetal risk, but no adequate human studies in pregnant women exist. First trimester: No evidence of teratogenicity; however, use only if clearly needed. Second and third trimesters: Generally considered safe; no known fetal adverse effects. Potential for alteration of gut flora in neonate if administered near term. |
■ FDA Black Box Warning
None
| Serious Effects |
["Absolute: Known hypersensitivity to cephradine, any cephalosporin, or any component of the formulation.","Relative: History of immediate-type hypersensitivity reaction (e.g., anaphylaxis) to penicillins (cross-sensitivity occurs in 5-10% of patients); avoid use if severe reaction to penicillins."]
| Precautions | ["Hypersensitivity reactions: Cross-allergenicity with penicillins and other beta-lactams; serious and occasionally fatal hypersensitivity reactions (anaphylaxis) have been reported.","Antibiotic-associated pseudomembranous colitis (Clostridioides difficile infection) can occur with use.","Renal impairment: Dosage adjustment required in patients with creatinine clearance <30 mL/min to avoid accumulation and neurotoxicity.","Prolonged use may result in overgrowth of nonsusceptible organisms, including Candida and Clostridium difficile.","Caution in patients with history of gastrointestinal disease, particularly colitis."] |
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| Fetal Monitoring | No specific monitoring required beyond routine prenatal care. In prolonged use, monitor maternal renal function and complete blood count (CBC) due to potential for neutropenia. Fetal monitoring: No specific indications, but standard fetal surveillance if maternal infection severe. |
| Fertility Effects | No known adverse effects on human fertility. Animal studies show no impairment of fertility. |