Imipenem/Cilastin
Mechanism :
The bactericidal activity of imipenem results from the inhibition of cell wall synthesis. Its greatest affinity is for penicillin-binding proteins (PBPs). Imipenem has a high degree of stability in the presence of beta-lactamases, including penicillinases and cephalosporinases produced by gram-negative and gram-positive bacteria. Cilastatin sodium is the sodium salt of a derivatized heptenoic acid.
Indication :
- Pseudomonas infection Burkholderia cepacia infection Aerobic and anaerobic gram positive and gram-negative infections.
Contraindications :
Contraindicated in patients who have shown hypersensitivity to any component of this product, in patients with a known hypersensitivity to local anesthetics of the amide type as lidocaine is used as a diluent, and in patients with severe shock or heart block.
Dosing :
Under 1 week, >1.5 kg:
25 mg/kg given intravenously twice daily for infections not related to CNS.
1-4 weeks, >1.5 kg:
25 mg/kg given intravenously four times a day for infections not related to CNS.
4 weeks-3 months, 1.5 kg:
25 mg/kg given intravenously four times a day for infections not related to CNS.
>3 months:
15-25 mg/kg given intravenously every four hours for infections not related to CNS; maximum dose; 2 g/day for completely susceptible and 4 g/day for moderately susceptible organisms.
>12 years:
10-15 mg/kg given intravenously every four hours for mild to moderate infections.
For patients with cystic fibrosis:
Upto 100 mg/kg/day given intravenously in four divided doses; maximum dose: 4 g/day.
Adverse Effect :
Nausea, vomiting, diarrhea, rash, eosinophilia, decreased erythrocytes, decreased hemoglobin and hematocrit, increased and decreased platelets, increased and decreased WBC, and increased prothrombin time, thrombophlebitis, increased bilirubin, AST, alkaline phosphatase, ALT, increased creatinine and BUN, presence of white blood cells, red blood cells, casts, and bacteria in the urine, false positive Coomb’s test, seizures.
Interaction :
Probenecid: results in only minimal increases in plasma levels of imipenem and its plasma half-life.
Use with caution with nephrotoxic drugs and general seizures may occur on concurrent use with ganciclovir.
Renal Dose :
Dose in Renal Impairment GFR (mL/min)
| 31-70 | 500 mg every 6–8 hours |
| 21-30 | 500 mg every 8–12 hours |
| <20 | 250–500 mg (or 3.5 mg/kg whichever is lower) every 12 hours |
Dose in Patients undergoing Renal Replacement Therapies
| CAPD | Dialysed. Dose as in GFR<20 mL/ min |
| HD | Dialysed. Dose as in GFR<20 mL/ min |
| HDF/High flux | Dialysed. Dose as in GFR<20 mL/ min |
| CAV/VVHD | Dialysed. 250 mg every 6 hours or 500 mg every 8 hours |
| CVVHD/HDF | Dialysed. 250 mg every 6 hours or 500 mg every 6–8 hours |
Hepatic Dose :
No dosage adjustments are recommended.