Antimicrobials
Imipenem-Cilastatin

Imipenem-Cilastatin

Restricted

Medium
N/A
See below under General Info

Spectrum of Activity

Dosing

General Information

Hospital Formulary Status Yes (parenteral inj)

In-Hospital Cost will be updated

PharmaCare Formulary Status Yes (parenteral inj)

Special Authority None

PharmaCare Coverage 500mg powder for soln/inj - $40.0809/vial

Outpatient Cost 250mg powder for soln/inj - $12.68-13.95/vial 500mg powder for soln/inj - $47.39-52.13/vial

Restrictions Status: Yes (inj)

Restricted to:

1) Empiric therapy: Severe Gram-negative or polymicrobial infections in patients with risk factors for resistance, or when other antibiotics are contraindicated due to allergy or intolerance

OR

2) Empiric or directed therapy of Nocardia or non-tuberculous mycobacterial infections where indicated

OR

3) Directed therapy: Gram-negative or polymicrobial infections resistant to other antibiotics (e.g. ceftriaxone, fluoroquinolones, cotrimoxazole), or when other antibiotics are contraindicated due to allergy or intolerance.

Note: Pharmacists are NOT required to enforce compliance with new provincial ‘indication based’ restrictions at the time of order verification.

For additional assistance in optimizing this order, contact an Antimicrobial Stewardship pharmacist, medical microbiologist on call or an ID physician.

Acute liver injury (mainly with IV)

  • usually mild and self-limiting
  • involves cholestatic hepatitis and elevations in ALT, AST and alkaline phosphatase
  • liver failure is rare

Neutropenia (mainly with IV)

  • associated with immune-mediated destruction of polymorphonuclear leukocytes
  • sx: abrupt onset of fever, rash, and eosinophilia

Thrombocytopenia (mainly with IV)

  • acute immune-mediated
  • usually platelet count normalizes within 2 weeks after discontinuation

Allergic interstitial nephritis (mainly with IV)

  • sx: acute and often severe renal failure, with active urinary sediment (hematuria, proteinuria, and pyuria) but no red cell casts
  • usually signs of hypersensitivity are present (fever, peripheral eosinophilia, eosinophiluria and rash)
  • several cases of cross-sensitivity between beta-lactam antibiotics

Pulmonary infiltrate with eosinophilia (PIE) syndrome (mainly with IV)

  • sx: abrupt onset of fever, chills, dyspnea, pulmonary infiltrates and peripheral eosinophilia

CNS toxicity (mainly with IV)

  • sx: seizures
  • onset: 7 days after initiation
  • correlates with high doses, renal dysfunction, or underlying CNS disease
  • greater convulsive activity than meropenem

Allergic reaction (PO and IV)

  • IgE-mediated
  • sx: pruritus, flushing, urticaria, angioedema, wheezing, laryngeal edema, hypotension, and/or anaphylaxis
  • sx usually appear within 4 hrs of administration but may begin within mins

Serum sickness (PO and IV)

  • late allergic reaction
  • sx: fever, rash, adenopathy, arthritis and glomerulonephritis
  • associated with circulating immune complexes

Rash (PO and IV)

  • includes morbilliform rash, erythema multiforme, SJS, exfoliative dermatitis, toxic epidermal necrolysis and vasculitis
  • sx: photosensitivity, skin lesions, mucosal membrane ulceration, erythema, scaling, palpable purpura and/or positive Nikolsky's sign

Note: EBV-related rash - not an allergy

  • morbilliform rash, occurring 48 hrs to weeks after initial amoxicillin exposure in patients with Epstein Barr Virus, does not appear to be a true drug allergy

May decrease serum concentrations of valproic acid.

May increase risk of seizures with ganciclovir, valganciclovir.

Cyclosporine may increase risk of seizures with imipenem.

Antimicrobial class: Carbapenem

Imipenem-cilastatin is the preferred carbapenem for polymicrobial infections where Enterococcus faecalis is prominent in culture.

Average serum half life: 1.0 hr

CSF penetration: yes, but meropenem preferred for CNS infections due to seizure risk with imipenem-cilastatin