Doxycycline

General

  • Type: Tetracyclines
  • Dosage Forms: PO and IV (20mg, 50mg, 75mg, 100mg, 150mg, 25mg/5 mL)
  • Common Trade Names: Adoxa, Avidoxy, Doryx, Monodox, Oracea, Periostat, Vibramycin

Adult Dosing

General Infections

  • 100mg PO/IV QD or q12h depending on severity
    • Variable duration




Indications by Disease

DiseaseDoseContext
Acne vulgaris100mg PO dailySevere acne vulgaris
Acute diarrhea300mg PO as single doseVibrio cholerae
Acute necrotizing ulcerative gingivitis100 mg PO BID x 10 daysUncomplicated
Anthrax100mg IV q12hrs x 60 daysInhalation/cutaneous with systemic illness; only if allergic to ciprofloxacin
Anthrax100mg PO q12hrs x 60 daysPostexposure prophylaxis
Anthrax100mg PO q12hrs x 60 daysCutaneous anthrax, not systemically ill
Bell's palsyempiric dosingLyme Suspicion
Cellulitis100mg PO/IV q12hrs dailySaltwater
Cervicitis100 mg PO BID x 7 daysGC/Chlamydia, Nonpregnant
Chlamydia trachomatis100mg PO q12h x 7 days; Also prophylaxis for sexual assault victimsChlamydia
Diabetic foot infection100mg PO q12hrs daily x 14 daysMild DFI
Ehrlichiosis100mg PO/IV BID x 14 daysAdults
Encephalitis200 mg IV once followed by 100 mg IV twice dailyTick Associated
Epididymitis100 mg orally twice a day for 10 daysSTI
Gonorrheal conjunctivitis100mg PO BID for 7 daysChlamydial Conjunctivitis
Infectious tenosynovitis100mg PO twice dailyGonococcal
Lymphogranuloma venereum100mg PO BID x 21 daysFirst Choice
Malaria100mg PO dailyProphylaxis
Mammalian bites100mg PO BID x 14 daysCat and dog bites penicillin allergic
Pelvic inflammatory disease100mg PO or IV q12hrInpatient
Pelvic inflammatory disease100mg PO BID x 14 daysOutpatient
Periodontitis100mg PO daily (as adjunct to scaling and root planing)Periodontitis
Plague200mg (2.2mg/kg) PO/IV dailyActive disease
Plague100mg (2.2mg/kg) PO q12hrsPostexposure prophylaxis
Pneumonia (main)100 mg BIDOutpatient, Unhealthy
Pneumonia (main)100mg IV/PO BIDInpatient, CAP Non-ICU
Pneumonia (main)100 mg twice dailyOutpatient, Healthy
Postpartum endometritis100mg IV/PO q12hrs<48hrs postpartum; combined with Ampicillin/Sulbactam or Cefoxitin
Postpartum endometritis100mg IV or PO q12hrs>48hrs postpartum; combined with Metronidazole
Proctitis100mg PO q12h x 7 daysProctitis
Prostatitis100mg PO q12 hrs x14 daysSTD Associated
Rocky mountain spotted fever100mg PO BID x 5-7 daysFirst line
Syphilis100mg oral twice daily for 4 weeksLate Stage, Alternative
Syphilis100mg oral twice daily for 14 daysEarly Stage, Alternative
Tularemia100mg (2.2mg/kg) IV q12hrs x 14 daysActive disease
Tularemia100mg PO q12hrs x 14 daysPostexposure prophylaxis
Urethritis in men100 mg PO BID x 7 daysUncomplicated, Chlamydia

Pediatric Dosing

General Infections

  • >8 years old
  • 2.2mg/kg PO/IV QD
    • Start: 2.2mg/kg PO/IV q12h x 1 day
    • Max 100mg/kg/dose
    • Frequency for severe infections is q12h








Indications by Disease

DiseaseDoseContext
Acne vulgaris>8 years old: weight <45kg: 2.2mg/kg/dose PO QD-BID; weight >45kg: adult dosingSevere acne vulgaris
Anthrax2.2mg/kg PO q12hrs x 60 daysPediatric postexposure prophylaxis
Anthrax2.2mg/kg IV q12hrsPediatric; only if allergic to cipro
Chlamydia trachomatis>8 years old; 100mg PO q12h x 7 days; Also prophylaxis for sexual assault victimsChlamydia
Ehrlichiosis2.2mg/kg PO/IV BIDPediatric under 45kg
Encephalitis2.2mg/kg IV q12hrs (max 100mg/dose)Pediatric Tick Associated
Lyme disease>8 years old; 100mg PO q12h x14-21 days; Treat for 28 days if Lyme arthritisLyme Disease
Malaria2.2 mg/kg/day PO daily (max 100mg/day), >8 years oldProphylaxis
Neisseria gonorrhoeae>8 years old/>45 kg; 100mg PO q12h x 7 days; Not first line- use with ceftriaxoneGonorrhea
Plague2.2mg/kg PO/IV q12hrs (max 100mg/dose)Pediatric Active Disease/Prophylaxis
ProctitisAdolescents; 100mg PO q12h x 7 daysProctitis
Rocky mountain spotted fever2.2mg/kg PO/IV BID (max 100mg/dose) x 5-7 days or until afebrile x 3 daysPediatric First Line
Tularemia2.2mg/kg PO/IV q12hrs x 14 days (max 100mg/dose)Pediatric Active Disease/Prophylaxis

Special Populations

  • Pregnancy: D
  • Lactation: Possibly Unsafe; consider alternatives
  • Renal Dosing Adult and Pediatric
    • No adjustment
  • Hepatic Dosing Adult and Pediatric
    • Not defined

Contraindications

  • Allergy to class/drug
  • Pregnancy
  • Age <8 years
    • Doxycycline is less likely to cause dental staining, especially short course
    • AAP now permits Doxycyline use if less than 21 days treatment duration[1]
  • Caution:
    • Lupus
    • Child bearing potential
    • Hepatic impairment
    • Candidiasis
    • Recent colitis due to antibiotics

Adverse Reactions

Serious

  • Tooth discoloration children <8 years old (Controversial)[2]
  • Photosensitivity
  • C. Diff diarrhea
  • Hypersensitivity reaction
  • Skin reaction
  • Vasculitis
  • Pericarditis
  • Autoimmune hepatitis
  • Hepatotoxicity
  • Nephrotoxicity
  • Esophagitis/ulcer
  • Pancreatitis
  • Thrombocytopenia
  • Neutropenia
  • Hemolytic anemia
  • Pseudotumor cerebri
  • Bulging fontanelles
  • Jarisch-Herxheimer reaction
  • Fetal harm

Common

  • Headache
  • Nausea
  • Dyspepsia
  • Arthralgia
  • Diarrhea
  • Rash
  • Dysmenorrhea
  • Photosensitivity
  • Vulvovaginal candidiasis
  • Skin discoloration
  • Elevated BUN

Pharmacology

  • Half-life: 18 hours
  • Metabolism: Unknown and minimal liver/CYP450
  • Excretion: Feces and urine
  • Mechanism of Action: Bacteriostatic

Antibiotic Sensitivities[3]

Group Organism Sensitivity
Gram Positive Strep. Group A, B, C, G I
Strep. Pneumoniae S
Viridans strep X1
Strep. anginosus gp X1
Enterococcus faecalis R
Enterococcus faecium R
MSSA I
MRSA I
CA-MRSA S
Staph. Epidermidis R
C. jeikeium R
L. monocytogenes S
Gram Negatives N. gonorrhoeae I
N. meningitidis S
Moraxella catarrhalis S
H. influenzae S
E. coli S
Klebsiella sp I
E. coli/Klebsiella ESBL+ I
E coli/Klebsiella KPC+ R
Enterobacter sp, AmpC neg R
Enterobacter sp, AmpC pos R
Serratia sp X1
Serratia marcescens R
Salmonella sp I
Shigella sp I
Proteus mirabilis X1
Proteus vulgaris R
Providencia sp. X1
Morganella sp. X1
Citrobacter freundii X1
Citrobacter diversus X1
Citrobacter sp. X1
Aeromonas sp X1
Acinetobacter sp. R
Pseudomonas aeruginosa R
Burkholderia cepacia R
Stenotrophomonas maltophilia X2
Yersinia enterocolitica R
Francisella tularensis S
Brucella sp. S
Legionella sp. X2
Pasteurella multocida X1
Haemophilus ducreyi R
Vibrio vulnificus S+'
Misc Chlamydophila sp S
Mycoplasm pneumoniae S
Rickettsia sp S
Mycobacterium avium R
Anaerobes Actinomyces S
Bacteroides fragilis I
Prevotella melaninogenica S
Clostridium difficile X1
Clostridium (not difficile) S
Fusobacterium necrophorum X1
Peptostreptococcus sp. S

Key

  • S susceptible/sensitive (usually)
  • I intermediate (variably susceptible/resistant)
  • R resistant (or not effective clinically)
  • S+ synergistic with cell wall antibiotics
  • U sensitive for UTI only (non systemic infection)
  • X1 no data
  • X2 active in vitro, but not used clinically
  • X3 active in vitro, but not clinically effective for Group A strep pharyngitis or infections due to E. faecalis
  • X4 active in vitro, but not clinically effective for strep pneumonia

See Also

References

  1. American Academy of Pediatrics. Tetracyclines. In: Red Book: 2018 Report of the Committee on Infectious Diseases, 31st ed, Kimberlin DW, Brady MT, Jackson MA, Long SS (Eds), American Academy of Pediatrics, Itasca, IL 2018. p.905.
  2. The end of a dogma: the safety of doxycycline use in young children for malaria treatment https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5390373/
  3. Sanford Guide to Antimicrobial Therapy 2014