VEETIDS '500'
Clinical safety rating: caution
Comprehensive clinical and safety monograph for VEETIDS '500' (VEETIDS '500').
VEETIDS '500' (cefuroxime axetil) is a second-generation cephalosporin antibiotic that inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), thereby blocking transpeptidation and leading to cell lysis. It has activity against both gram-positive and gram-negative bacteria.
| Metabolism | Cefuroxime axetil is de-esterified to the active cefuroxime. Cefuroxime is primarily eliminated unchanged by the kidneys via tubular secretion and glomerular filtration. It is not significantly metabolized; approximately 50% is excreted unchanged in urine within 24 hours. |
| Excretion | Renal: 60-80% unchanged; biliary/fecal: 15-25% as metabolites |
| Half-life | 4-6 hours (prolonged in renal impairment; requires dose adjustment if CrCl <30 mL/min) |
| Protein binding | 15-25% (primarily albumin) |
| Volume of Distribution | 0.2-0.3 L/kg (limited to extracellular fluid; poor CNS penetration unless inflamed) |
| Bioavailability | Oral: 80-95% (enhanced by food; reduced by antacids) |
| Onset of Action | Oral: 30-60 minutes; IV: immediate |
| Duration of Action | 12 hours (clinical effect wanes as serum levels fall below MIC; dosing interval 12-24 hours depending on infection site) |
| Molecular Weight | 587.6 |
1 tablet (500 mg) orally twice daily for 7 days.
| Dosage form | TABLET |
| Renal impairment | CrCl >= 30 mL/min: no adjustment; CrCl 10-29 mL/min: 500 mg once daily; CrCl < 10 mL/min: 500 mg every 48 hours. |
| Liver impairment | Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 50%; Child-Pugh C: contraindicated. |
| Pediatric use | Not recommended for use in pediatric patients (safety and efficacy not established). |
| Geriatric use | No specific adjustment required; monitor renal function due to age-related decline. |
| 1st trimester | Avoid; associated with fetal nephrotoxicity and ototoxicity. |
| 2nd trimester | Avoid; potential for fetal nephrotoxicity and ototoxicity. |
| 3rd trimester | Avoid; risk of neonatal nephrotoxicity and ototoxicity. |
Clinical note
Comprehensive clinical and safety monograph for VEETIDS '500' (VEETIDS '500').
| Placental transfer | Crosses placenta; detectable in fetal serum and amniotic fluid. |
| Breastfeeding | Small amounts excreted in breast milk; avoid due to risk of infant nephrotoxicity and ototoxicity. Consider alternative if possible. |
| Lactation Rating | L5 (Contraindicated) |
■ FDA Black Box Warning
None
| Serious Effects |
Hypersensitivity to vancomycinPrevious severe ototoxicity with vancomycinAnuria
| Precautions | Warnings: hypersensitivity reactions including anaphylaxis; Clostridioides difficile-associated diarrhea (CDAD); seizure potential, especially in patients with renal impairment; decreased prothrombin activity and bleeding risk; interference with glucose testing (false-positive urine glucose with copper reduction methods). |
| Food/Dietary | No significant food interactions. May be taken with or without food. Maintain adequate fluid intake. |
| Clinical Pearls |
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| Teratogenic Risk | Teratogenic risk profile: FDA Pregnancy Category D. First trimester: Potential for fetal harm based on animal studies and human data; may cause fetal malformations, including neural tube defects and cardiac anomalies. Second trimester: Continued risk of fetal growth restriction and oligohydramnios. Third trimester: Risk of premature closure of ductus arteriosus and pulmonary hypertension in the neonate; avoid use after 20 weeks of gestation. |
| Fetal Monitoring | Maternal-fetal monitoring: Monitor maternal blood pressure, renal function, and serum drug levels (if applicable). Fetal ultrasound for growth assessment and amniotic fluid index; monitor for premature ductus arteriosus closure (if used beyond 20 weeks). |
| Fertility Effects | Fertility effects: No known adverse effects on human fertility. Animal studies have not shown impairment of fertility. |
| VEETIDS '500' is a formulation of valacyclovir (500 mg), an antiviral prodrug of acyclovir. It is used for herpes zoster (shingles), herpes simplex (genital herpes, cold sores), and varicella (chickenpox). Key pearls: (1) Ensure adequate hydration to prevent crystalluria, especially in elderly or renally impaired patients. (2) Dose adjustment required for CrCl <30 mL/min; for CrCl 10-29 mL/min, dose every 12-24 hours depending on indication. (3) May cause thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS) in immunocompromised patients. (4) Faster healing and decreased viral shedding if started within 72 hours of rash onset for herpes zoster. |
| Patient Advice | Take exactly as prescribed; do not skip doses to reduce viral resistance. · Drink plenty of water (at least 8 glasses daily) to prevent kidney problems. · Start treatment at the first sign of symptoms (tingling, burning, or rash) for best results. · Use barrier contraception (condoms) during outbreaks to reduce transmission; medication does not cure herpes or prevent spread. · Avoid sharing personal items like towels or razors during active lesions. |