Antimicrobials
Tetracycline

Tetracycline

Low
Good (70 to 90%)

Spectrum of Activity

Dosing

General Information

  • Use during last half of pregnancy, infancy or in children < 8 years can cause permanent yellow discolouration of the teeth.
  • Toxic to human embryos (impaired skeletal development, mental retardation)
  • Tetracyclines have an anti-anabolic effect that can manifest as an increase in BUN. This can aggravate azotemia, raise serum phosphorus levels and worsen acidosis.
  • Drug accumulation can be toxic to the liver.
  • Photosensitivity
  • Tetracycline increases levels of warfarin, digoxin.
  • Major substrate of CYP3A4 - levels affected by co-administration with inducers and inhibitors of CYP3A4.

Derivatives of tetracycline such as doxycycline and minocycline are more active with convenient dosing and therefore are used more often.

Pharmacology: Inhibits bacterial protein synthesis by binding with the 30S and possibly the 50S ribosomal subunit(s) of susceptible bacteria.

Antimicrobial class: Tetracyclines

Pregnancy category: D

Average serum half life: 6 - 11 hours

Biliary penetration: 200 - 3200 % of plasma concentration

CSF penetration: Poor

Metabolism: Majority not metabolised and excreted in urine and faeces.

Route of Elimination: Renal: 30% GI: 20 - 60%