Staphylococcus aureus, Streptococcus pneumonia, Streptococcus pyogenes, Streptooccus agalacticae, Campylobacter jejuni, Haemophilus influenzae, Neisseria gonorrhoeae, Neisseria meningitides,Clostridium spp., Peptostreptococcus spp., Peptococcus spp. Bacteroides melaninogenicus, Bacteroides fragilis
Inhibits bacterial protein synthesis by binding with the 30S ribosomal subunit.
Tetracyclines produce a combination of concentration and time-dependent killing (AUC:MIC ratio).
Dose of 500mg PO: Cmax: 1.5-5 mcg/mL; Tmax: 2-4 hours; Half-life: 6-12 hours; Volume of distribution: 108 L/kg; Table 3
GI: epigastric burning, abdominal discomfort, nausea, vomiting, anorexia, diarrhea, esophagitis, esophageal ulcers, dysphagia, candidal superinfections
Teeth and bone: (dose/duration related) yellow discoloration of teeth, which turns into a gray-brown permanent discoloration, hypoplasia of enamel, teeth demineralization, skeletal growth retardation
Hepatotoxicity: rare, but fatal; intrahepatic cholestasis, jaundice, azotemia, acidosis, irreversible shock
Renal Toxicity: hyperphosphatemia, acidosis, polyuria, polydipsia
Photosensitivity and hyperpigmentation: red rash to blistering on sun-exposed areas; photoallergic reactions manifested by paresthesias of hands, feet, nose, photo-onycholysis
Auditory: tinnitus, hearing loss
Vision: visual disturbances
CNS: lightheadedness, dizziness, ataxia, drowsiness, headache
Oral: 250mg, 500mg capsules
Acne vulgaris: 250 mg PO q other day to 500 mg PO q24h
Bartonellosis: 1-2 g/day divided PO in 2-4 doses
Brucellosis: 500 mg PO q6h 4 x 3 plus streptomycin
Chlamydia psitacci infection: 1-2 g/day divided PO in 2-4 doses
Rickettsial disease: 1-2 g/day divided PO in 2-4 doses
Nongonococcal urethritis: 500 mg PO q6h x 7 days
25-50mg/kg/day in 2 to 4 divided doses OR 0.6-1.2g/m2 in 2 – 4divided doses
Renal failure: CrCl > 50mL/min: 250mg to 500mg q6h
CrCl 10-50 mL/min: 250mg to 500mg q12h to q24h
CrCl < 10 mL/min: Not recommended
Hepatic failure: No dosing changes recommended at this time.
Contraindications: Hypersensitivity to tetracycline antibiotics.
Precautions: Usage in newborns, infants, and children less than 8 years of age; risk for tooth discoloration; Renal or liver impairment; Phototoxicity; Veneral disease with suspected coexistent syphilis
Oral contraceptives: Decreased contraceptive effectiveness
Warfarin: Increased warfarin effect
Barbiturates, phenytoin, carbamazepine: Decreased serum concentrations of doxycycline
Ethanol: Decreased doxycyline serum concentrations
Antacids, didanosine, sucralfate, multivitamins: decreased tetracycline absorption
Kaolin, bismuth subsalicylate: decreased absorption of tetracycline
Food: Decreased absorption of tetracycline
Milk: Decreased absorption of tetracycline
Category D: Risk established, but benefits may outweigh risk.
Therapeutic: Culture and sensitivities, serum levels, signs and symptoms of infection, white blood cell count
Toxic: Hypersensitivity syndrome reaction, serum sickness like reaction or single organ dysfunction – Monitor: CBC, LFTs, urinalysis, urea, creatinine, chest radiograph; Drug-induced lupus: monitor antinuclear antibody and hepatic transaminases; General long-term therapy: Liver and renal function tests, Hematopoietic studies
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