Doxycycline

Antibiotic Class:

Tetracyclines

Antimicrobial Spectrum:

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

Mechanism of Action:

Inhibits bacterial protein synthesis by binding with the 30S ribosomal subunit.

Pharmacodynamics:

Tetracyclines produce a combination of concentration and time-dependent killing (AUC:MIC ratio).

Pharmacokinetics:

Dose of 200mg PO: Cmax: 1.5-3.6 mcg/mL; Tmax: 1.5-4 hours; Half-life: 14-24 hours; Volume of distribution: 50 L/kg; Table 3

Adverse Effects:

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

Dosage:

Oral: 20mg, 50mg, 100mg capsules

         25mg/5mL suspension

         50mg, 75mg, 100mg tablets

IV: 100mg Solution for injection

Dosing in adults (common indications):

Lyme disease: 100-200 mg/day PO x 10-20 days

Periodontitis: 20mg 20 mg PO q12h for up to 9 months

Chlamydial infection: 100 mg PO q12h x 7 days

Bacterial infectious disease, Susceptible infections due to Vibrio cholerae, Brucella species, Rickettsiae, Yersinia pestis, Francisella tularensis, M. pneumoniae: 100 mg PO q12h

Table 4, Table 7

Dosing in pediatrics:

2.2-4.4 mg/kg/day in 1-2 divided doses

Table 4, Table 7

Disease state based dosing:

Renal failure:     None necessary           

Hepatic failure:  No dosing changes recommended at this time.

Contraindications/Warnings/Precautions:

Precautions:  Usage in newborns, infants, and children less than 8 years of age risk for tooth discoloration; Phototoxicity

Drug Interactions:

Warfarin: Increased anticoagulant effect

Barbiturates, phenytoin, carbamazepine: Decreased serum concentrations of doxycycline

Oral contraceptives: Decreased contraceptive effectiveness

Ethanol: Decreased doxycyline serum concentrations

Table 6

Pregnancy:

Category D: Risk established, but benefits may outweigh risk.

Monitoring Requirements:

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

Brand names/Manufacturer: 

ABADOX (Lafar - ITALY)

ACNE-CY-CLEAN (Brovar - SOUTH AFRICA)

ACTIDOX (Saninter - PORTUGAL)

ADOXA (Bioglan - USA)

AKNEFUG DOXY (Wolff - GERMANY)

AK-RAMYCIN CAPSULE  (AKORN - U.S.)

AK-RATABS TABLET (AKORN - U.S.)

ALIUDOX (Aliud - AUSTRIA)

AMBRODOXY (Hexal- GERMANY)

AMBROXOL AL COMP (Aliud - GERMANY)

AMDOX-PUREN (Alpharma-Isis - GERMANY)

AMERMYCIN - (Unison, Thai. THAILAND, HONG KONG)

ANTODOX (Q-Pharm - GERMANY)

APOCICLINA (Protein - MEXICO)

APODOXIN (Alpharma - FINLAND)

APO-DOXY (Apotex CANADA, SINGAPORE, CZECH REPUBLIC)

ATRIDOX (Meda FINLAND, SWEDEN, DENMARK, GERMANY, SWITZERLAND, USA, UNITED KINGDOM)

AZUDOXAT (Azupharma, Ger. - GERMANY)

AZUDOXAT-T (Azuchemie GERMANY)

DORYX (Faulding AUSTRALIA, SINGAPORE, SWEDEN, SOUTH AFRICA)

DORYX (Warner Chilcott - USA)

DORYX (Parke, Davis, CANADA)

DOSIL ENZIMATICO (Llorens - SPAIN)

DOSYKLIN (Leiras- FINLAND)

DOTUR (Biochemie- AUSTRIA)

DOXACLEN (Hortel - SPAIN)

DOXACYNE (Pharmaniaga- MALAYSIA)

DOXAKNE (Bioglan - GERMANY)

DOXY (1A - GERMANY)

DOXY (Vitamed - ISRAEL)

DOXYCYCLINE (Various Manufacturers U.S.)

VIBRAMICINA (Pfizer PORTUGAL, BRAZIL, MEXICO, CHILE)

VIBRAMYCIN (Pfizer  UNITED KINGDOM, GERMANY, NETHERLANDS, SOUTH AFRICA, SWEDEN, NORWAY, AUSTRIA, IRELAND, HONG KONG, ISRAEL, THAILAND, SINGAPORE, AUTRALIA, MALAYSIA, GREECE, HUNGARY, USA, SWITZERLAND, BELGIUM, FRANE, CANADA, DENMARK, GERMANY)