tigecycline

Brand: Tygacil

⚠ BBW Prototype Drug
Drug Class: glycylcycline antibiotic
Drug Family: antibiotic
Subclass: expanded-spectrum tetracycline analog
Organ Systems: infectious-disease

Mechanism of Action

Binds 30S ribosomal subunit with higher affinity than tetracyclines due to the 9-glycylamido group; overcomes tetracycline resistance mechanisms including ribosomal protection and efflux pumps; bacteriostatic with extremely broad spectrum.

30S ribosomal subunit

Indications

  • complicated skin/soft tissue infections (cSSSI)
  • complicated intra-abdominal infections (cIAI)
  • community-acquired bacterial pneumonia (CABP)

Contraindications

  • tigecycline hypersensitivity
  • pregnancy
  • children <8 years

Adverse Effects

Common

  • nausea (very frequent, ~30%)
  • vomiting
  • diarrhea

Serious

  • anaphylaxis
  • hepatotoxicity
  • pancreatitis
  • pseudotumor cerebri
  • increased all-cause mortality in severe infections (pooled analysis)

Pharmacokinetics (ADME)

Absorption IV only
Distribution very large volume of distribution (7–9 L/kg); excellent tissue penetration
Metabolism minimal
Excretion biliary/fecal (59%), renal (33%)
Half-life 42 hours
Onset immediate (IV)
Peak end of infusion
Duration 12 hours (twice-daily dosing)
Protein Binding 71–89%
Vd very large (7–9 L/kg)

Drug Interactions

Drug / Agent Mechanism Severity
warfarin tigecycline increases INR via gut flora suppression; monitor INR moderate
oral contraceptives gut flora disruption may reduce enterohepatic recirculation of estrogens minor

Nursing Considerations

  1. Pre-medicate with an antiemetic before each tigecycline dose; nausea and vomiting occur in up to 30% of patients and are the primary tolerability issue.
  2. Administer IV over 30–60 minutes; infusion site reactions including phlebitis can occur.
  3. Given the FDA black box warning of increased mortality in severe infections, reserve tigecycline for infections without a superior alternative.
  4. Tigecycline does NOT achieve adequate blood concentrations for bacteremia; do not use as monotherapy when bacteremia is suspected.

Clinical Pearls

  • Tigecycline overcomes the two main tetracycline resistance mechanisms (ribosomal protection and efflux), giving it activity against many drug-resistant organisms including MRSA, ESBL producers, and Acinetobacter baumannii.
  • Its FDA black box warning notes higher all-cause mortality vs. comparators in pooled analyses of clinical trials; the mechanism is uncertain but may reflect inadequate serum concentrations in bacteremic patients due to its enormous Vd.

Safety Profile

Pregnancy contraindicated
Lactation avoid
Renal Adjustment Not required
Hepatic Adjustment Required
TDM Not required
Guideline Update pending