» Rat Guide     » Health Guide     » Care Guide     » Medication Guide     » Breeding Guide    


Antimicrobial Agents
Back to Antimicrobial Agents




Tablets: 250 mg & 500 mg
Suspension: 125 mg/5mL & 250 mg/5mL


Clarithromycin is a semi-synthetic macrolide antibiotic chemically related to erythromycin. It is bacteriostatic or bactericidal depending on the concentration given. Clarithromycin binds to the 50S subunit of bacterial ribosomes thereby blocking protein synthesis. It is active against both aerobic and anaerobic Gram-positive and Gram-negative microorganisms, as well as Mycoplasma pneumoniae and Mycobacterium avium.

Clarithromycin is absorbed rapidly from the gastrointestinal tract and distributed into body tissue and fluids, as well as crossing the placental barrier.

The drug is principally excreted via the liver and kidneys, hence caution should be used in hepatic and renal impairment.


Used for respiratory infections as well as uncomplicated skin and skin structure infections

Drug Interactions or Contraindications

Do not give with cisapride, pimozide, astemizole or terfendadine.

Clarithromycin may increase serum plasma levels of the following:

  • Cyclosporine
  • Digoxin
  • Disopyramide
  • Ranitidine bismuth citrate
  • Theophylline

Clarithromycin may also increase serum plasma levels of benzodiazepines and prolong CNS effects if given together.

Adverse Reactions

CNS:  loss of balance, behavioral changes

GI:  Abdominal pain, diarrhea, poor appetite.

Skin:  itching

Dosage Recommendations

*Rat approved dosages still being determined. Dosage in rats is empirical.*
1.5 mg/lb to 5 mg/lb , PO , BID  3

Consider prolonging dose intervals in severe renal impairment.


  • Because of it’s rapid absorption into tissue, there is less GI distress than with erythromycin.
  • May be given with or without food.
  • Store at room temperature in a tightly closed container, away from light.
  • Do not refrigerate the suspension.

Posted on June 23, 2003, 14:29, Last updated on August 31, 2013, 19:42 | Antimicrobial Agents

Rat Guide Logo
All other written and visual materials used by permission of specific authors for the sole use of the Rat Guide.
Brought to you by KuddlyKorner4u
See Logos page for linking to the Rat Guide.
Rat Guide brought to you by KuddlyKorner4u