C. diff Risk


Oral Bioavailability


Approximate Cost

Spectrum Of Activity


100mg PO BID

General Information

Common Usage

Skin and soft tissue infection, Methicillin resistant staphylococcus aureus infections, community acquired pneumonia, Malaria prophylaxis, Zoonoses

Adverse Effects

GI upset and erosive esophagitis

Photosensitivity rash

Teeth staining

Major Interactions

Divalent cations - decreased absorption

Some anticonvulsants can decrease doxycycline levels

Increased digoxin levels

Increased INR with warfarin

Di- & Trivalent cations including Al, Ca, Fe, Mg (anatacids, dairy products, iron supplements, some enteral feeds) - decreased absorption

Additional Information

May exacerbate muscle weakness in persons with myasthenia gravis. Contraindicated.


Antimicrobial class: Tetracycline

Pregnancy category: D

Average serum half life: 18.0

Biliary penetration: Therapeutic

CSF penetration: Poor

Lung penetration: Therapeutic

Urine penetration: Therapeutic