Antimicrobials
Doxycycline

Doxycycline

C difficile risk
Low
Oral Bioavailability
Excellent
Cost
See below under General Info

Dosing

100mg PO BID

General Information

Hospital Formulary Status Yes (PO solid)

In-Hospital Cost will be updated

PharmaCare Formulary Status Yes (PO solid)

Special Authority None

PharmaCare Coverage 100mg PO - $0.6329/tab or cap

Outpatient Cost 100mg PO - $0.69-1.10/tab or cap

  • Skin and soft tissue infection

  • Community acquired pneumonia

  • Malaria prophylaxis

  • Zoonoses

  • Susceptible MRSA infections

Gastritis (PO)

  • sx: abdominal discomfort, epigastric pain, nausea, vomiting, anorexia, esophageal ulcerations and strictures

  • may alter gut flora to cause large bulky stools and diarrhea, which usually subsides after discontinuation

  • patient with continued diarrhea, fever, and rising WBC count should be evaluated for antibiotic-associated diarrhea caused by C. Difficile

  • less risk than tigecycline

  • advise patient to take with food, plenty of water and not before bedtime

Allergic skin reactions (PO)

  • uncommon: hypersensitivity and photosensitivity reactions (red rash or blistering on areas exposed to the sun)

  • if patient is allergic to one tetracycline, they should be considered allergic to all

  • advise patient to avoid direct sunlight or wearing protective clothing and sunscreen

Teeth and bone toxicity (PO)

  • can cause brown to yellow teeth discoloration in children < 8 years old, which is associated with hypoplasia of enamel

  • discoloration on permanent teeth is dose-related and does not occur in adults

  • may deposit in bone due to chelate formation with calcium

  • avoid in children < 8 years old, but if tetracyclines must be used, doxycycline may be preferred

Hepatotoxicity (PO)

  • rare but can be fatal

  • more common with tetracycline and minocycline

  • less common with doxycycline

  • cholestatic liver injury is rare with a long latency of over 1 year but most recover after discontinuation

Renal failure exacerbation (PO)

  • tetracyclines inhibit protein synthesis

  • may exacerbate preexisting renal failure by increasing azotemia from amino acid metabolism

Jarisch-Herxheimer type reaction (PO)

  • can occur in patients with spirochetal infections (syphilis, tick-borne relapsing fever and louse-borne relapsing fever)

  • sx: fever, chills, headache, malaise, muscle aches, leukocytosis and exacerbation of cutaneous lesions

  • prevention: use of tumor necrosis factor antibodies and steroids

  • pretreatment: acetaminophen or meptazinol may reduce the symptoms and duration

Other uncommon ADRs

  • hemolytic anemia

  • thrombocytopenia

  • neutropenia

  • eosinophilia

  • pericardial effusions

  • Divalent cations - decreased absorption

  • Increased digoxin levels

  • Increased INR with warfarin

  • Some anticonvulsants can decrease doxycycline levels

Antimicrobial class: Tetracycline

Pregnancy category: D

Average serum half life: 18.0 hr

Urine penetration: Therapeutic

Lung penetration: Therapeutic

CSF penetration: Poor

Biliary penetration: Therapeutic