Demeclocycline

Staphylococcus aureus, Streptococcus pneumonia, Streptococcus pyogenes, Streptooccus agalacticae, Campylobacter jejuni, Enterobacter spp., Neisseria gonorrhoeae, Neisseria meningitides, Pseudomonas pseudomallei, Shigella spp., Clostridium spp., Peptostreptococcus spp., Bacteroides melaninogenicus

Mechanism of Action:

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

Pharmacodynamics:

AUC/MIC ratio predictive of pharmacodynamic activity.

Pharmacokinetics:

Dose of 300mg PO: Cmax: 0.9-1.7 mcg/mL; Tmax: 3-4 hours; Half-life: 10-17 hours; Volume of distribution: 121 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: 150mg, 300mg tablets

Adult dosing (primarily used in syndrome of inappropriate antidiuretic hormone secretion - SIADH):

SIADH: 600mg to 1200mg/day PO in 3 to 4 divided doses

Other indications: 150mg q6h OR 300mg q12h

Pediatric dosing:

6.6-13.2mg/kg/day in 2 to 4 divided doses OR 300mg/m² in 2 to 4 divided doses

Table 4

Disease state based dosing:

Renal failure: Demeclocycline should be avoided in patients with renal failure, as further deterioration of renal function may occur.

Hepatic failure: Demeclocycline should be avoided in patients with hepatic failure, as further deterioration of hepatic function may occur.

Contraindications/Warnings/Precautions:

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

Drug Interactions:

Oral contraceptives: Decreased contraceptive effectiveness

Warfarin: Increased warfarin effect

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 (eg fever), WBC

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:

Declomycin Ò/Lederle