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