Rocephin | Pharmacology Mentor

Generic Name

Rocephin

Inhibition of bacterial cell‑wall synthesis by binding to penicillin‑binding proteins (PBPs) – particularly PBP2, PBP3, and PBP4.
This prevents cross‑linking of the peptidoglycan layer, leading to osmotic lysis and bacterial death.
Exhibits bactericidal activity against Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, and many Enterobacteriaceae.
Resistant to most betalactamases; circumscribed by β‑lactamase‑producing organisms such as *Pseudomonas aeruginosa* and *Acinetobacter* spp.

Administration: intravenous (IV) or intramuscular (IM); no oral formulation.
Absorption: 90‑95 % bioavailable after IV/IM.
Distribution: Volume of distribution ≈ 0.3 L/kg; crosses the blood‑brain barrier and colonizes bile, amniotic fluid, and the CSF at adequate levels.
Protein binding: ~90 % (unbound fraction <10 %).
Half‑life: 8‑12 h in adults; 10‑11 h in pediatric patients.
Metabolism & Elimination: Primarily biliary excretion (~70 % fecal), with renal excretion contributing 20–25 %.
Special populations: Dose adjustments typically unnecessary in mild‑to‑moderate renal impairment; caution in severe renal dysfunction (creatinine clearance <30 mL/min) because of rising plasma levels and risk of tremor.
Drug interactions: May displace bilirubin from albumin, precipitating hyperbilirubinemia in infants; can precipitate with calcium‑containing solutions (e.g., calcium gluconate), or aqueous vancomycin solutions.

Infection	Recommended Dose	Frequency
Community‑acquired pneumonia	1–2 g IV/IM once daily	Once daily
Meningitis (bacterial)	2 g IV/IM 12 h apart → 1–2 g q24 h	Once daily
Septicemia	1–2 g IV/IM q24 h	Once daily
Gram‑positive osteomyelitis	1–2 g IV/IM q24 h	Once daily
H. influenzae meningitis	1–2 g IV with lactulose	Once daily
Uncomplicated gonorrhea	1 g IM single dose	Single dose
Pre‑operative prophylaxis (e.g., CIED surgery)	1 g IV 30 min prior to incision	Single dose

> *Note:* Pediatric dosing is weight‑based (50–75 mg/kg/day; usually divided once daily).

Hypersensitivity to β‑lactam antibiotics (penicillin, cephalosporins).
History of anaphylactic reaction to ceftriaxone or other cephalosporins.
Disulfiram: Concurrent use may precipitate an alcohol‑disulfiram reaction.
Cholestatic liver disease: Can worsen jaundice; monitor LFTs.
Neonates <28 days: Contraindicated due to risk of neonatal hyperbilirubinemia and needle irritation.
Pregnancy: Category B; generally considered safe but avoid in first trimester if alternatives available.
Concurrent anticonvulsants (e.g., phenytoin, carbamazepine) may increase ceftriaxone clearance; monitor efficacy.

Adults (≥18 yrs)
*Severe infections* (e.g., meningitis, septicemia): 2 g IV/IM q24 h (or 1 g q12 h if special circumstances).
*Moderate infections* (e.g., pneumonia, uncomplicated gonorrhea): 1–1.5 g IV/IM q24 h.
Pediatrics
50–75 mg/kg/day, divided once daily.
*Severe infections* can be increased to 100 mg/kg/day.
Infusion time: 30–60 min IV; IM injection uses 25 mg/kg up to 2 g per dose.
Reconstitution: Dissolve powder in normal saline (NS) or 5% dextrose; do not mix with calcium or magnesium solutions.
Route: Prefer IV over IM for deep infections to ensure consistent absorption.
Duration: Typically 7–14 days for uncomplicated infections; shorter for uncomplicated gonorrhea (single dose).

Adverse Effect	Incidence	Notes
Allergic rash / urticaria	Mild	Cross‑reactivity with penicillins.
Infusion site pain / phlebitis	Common	Slow infusion reduces incidence.
Gastro‑intestinal upset	Mild	Occurs in ~10 %; nausea, diarrhea.
Hepatotoxicity (elevated LFTs, cholestatic jaundice)	<5 %	Monitor in patients with liver disease.
Thrombocytopenia	<2 %	Can be severe; consider platelet counts in prolonged therapy.
Pseudomembranous colitis	Rare	Similar to other cephalosporins.
Neonatal hyperbilirubinemia	Rare (neonates)	Avoid in infants 10 % for key organisms.

Baseline: CBC, serum creatinine, bilirubin, alkaline phosphatase, liver enzymes.
During therapy:
Renal/hepatic function every 3–5 days (or more frequently if impaired).
CBC if prolonged (>10 days) to screen for thrombocytopenia.
LFTs if signs of cholestasis (jaundice, dark urine).
Patient History: Evaluate for history of seizures, hepatic or renal insufficiency, drug allergies.
Infusion reaction monitoring: Observe for anaphylaxis during first 30–60 min.

Once‑daily dosing is practical owing to ceftriaxone’s long half‑life; facilitates outpatient therapy or clinic settings.
CSF penetration is robust (≈ 25‑30 % of serum levels): ideal first‑line for bacterial meningitis.
Avoid mixing ceftriaxone with calcium‑containing solutions (e.g., calcium gluconate, calcium chloride); precipitation can cause local complications and reduce efficacy.
Use caution in patients with known cross‑reactivity to cephalosporins; a penicillin allergy history warrants skin testing before use.
Bilirubin displacement: In neonates and infants, ceftriaxone can displace unconjugated bilirubin from albumin, precipitating kernicterus; hence contraindicated in infants <28 days.
Renal impairment: Since 30‑35 % of the drug is renally cleared, but predominately biliary, a dose adjustment is rarely required unless CrCl  Key Takeaway: Rocephin is a versatile, long‑acting cephalosporin favored for acute bacterial infections, particularly when CSF penetration and once‑daily dosing are desired. Balance its broad spectrum with vigilance for allergic reactions, hepatic effects, and potential bilirubin displacement.