CEPHRADINE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for CEPHRADINE (CEPHRADINE).
Cephradine is a first-generation cephalosporin antibiotic that inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), leading to cell lysis and death.
| Metabolism | Cephradine is minimally metabolized in the liver; the majority of the drug is excreted unchanged in the urine via glomerular filtration and tubular secretion. |
| Excretion | Primarily renal (≥90% unchanged via glomerular filtration and tubular secretion); minor biliary/fecal (<10%). |
| Half-life | Terminal elimination half-life 0.5–1.5 hours (normal renal function); prolonged to 6–15 hours in severe renal impairment (CrCl <10 mL/min). |
| Protein binding | 6–20% bound to plasma proteins (primarily albumin). |
| Volume of Distribution | Vd 0.25–0.5 L/kg; reflects distribution into extracellular fluid and tissues (e.g., kidney, liver). |
| Bioavailability | Oral: >90% (capsules and suspension); IM: approximately 100%. |
| Onset of Action | Oral: 30–60 minutes; IM: 15–30 minutes; IV: immediate. |
| Duration of Action | 6–12 hours (dose-dependent; sustained for susceptible organisms). |
250-500 mg orally every 6 hours; 500 mg to 1 g intramuscularly or intravenously every 6 hours. Maximum: 4 g/day.
| Dosage form | FOR SUSPENSION |
| Renal impairment | CrCl >50 mL/min: no adjustment; CrCl 25-50 mL/min: 500 mg every 6 hours; CrCl 10-25 mL/min: 500 mg every 12 hours; CrCl <10 mL/min: 500 mg every 24 hours. |
| Liver impairment | No dose adjustment required as cephradine is primarily renally eliminated. Use with caution in severe hepatic impairment. |
| Pediatric use | Children >9 months: 25-50 mg/kg/day orally in 4 divided doses; 50-100 mg/kg/day intramuscularly or intravenously in 4 divided doses. Maximum: 4 g/day. |
| Geriatric use | Dose based on renal function. Start at lower end of dosing range and monitor renal function. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for CEPHRADINE (CEPHRADINE).
| Breastfeeding | Cephradine is excreted into human milk in small amounts (M/P ratio not established). The American Academy of Pediatrics considers cephalosporins compatible with breastfeeding. However, potential for alteration of infant gut flora and hypersensitivity exists. Use with caution, monitoring infant for diarrhea or allergic reactions. |
| Teratogenic Risk | Cephradine is a first-generation cephalosporin. Animal studies have not revealed evidence of teratogenicity or fetal harm. However, there are no adequate and well-controlled studies in pregnant women. Cephalosporins are generally considered low risk; however, due to limited human data, it should be used during pregnancy only if clearly needed. The FDA pregnancy category is B. No specific fetal risks are known for any trimester. |
■ FDA Black Box Warning
There is no FDA black box warning for cephradine.
| Serious Effects |
["Hypersensitivity to cephradine, other cephalosporins, or any component of the formulation.","Use in patients with known anaphylactic reaction to penicillins (relative contraindication)."]
| Precautions | ["Serious and occasionally fatal hypersensitivity reactions (anaphylaxis) may occur, especially in patients with a history of penicillin allergy.","Clostridium difficile-associated diarrhea (CDAD) has been reported; consider in patients who develop diarrhea.","Dosage adjustment required in renal impairment.","Prolonged use may result in superinfection with non-susceptible organisms.","Use with caution in patients with a history of gastrointestinal disease, particularly colitis."] |
| Food/Dietary | Food delays absorption; avoid taking with meals. No specific food-drug interactions reported. |
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| Fetal Monitoring | Monitor for signs of maternal hypersensitivity reactions (rash, anaphylaxis), gastrointestinal disturbances, and superinfection. Fetal monitoring not routinely required. In prolonged therapy, monitor renal and hepatic function. |
| Fertility Effects | No adverse effects on male or female fertility have been reported in animal studies. Human data are lacking. No known impact on reproduction. |
| Clinical Pearls | Cephradine is a first-generation cephalosporin with activity similar to cephalexin. It is susceptible to hydrolysis by beta-lactamases, limiting coverage against Staphylococcus aureus. Administer on an empty stomach (1 hour before or 2 hours after meals) to maximize absorption. Dose adjustment required in renal impairment (CrCl <50 mL/min). May cause false-positive direct Coombs test and urine glucose tests using copper reduction methods. |
| Patient Advice | Take this medication on an empty stomach, at least 1 hour before or 2 hours after meals. · Complete the full course even if you feel better to prevent resistance. · Report any signs of allergy (rash, itching, swelling, difficulty breathing) immediately. · Notify your doctor if you have kidney disease or a history of penicillin allergy. · Do not stop abruptly without consulting your physician. |