Tetracycline

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Contents 1 More Specific Terms 2 Introduction 3 Indications 4 Contraindications 5 Dosage 6 Dosage-adjustment-in-renal-failure 7 Pharmacokinetics 8 Adverse-effects 9 Drug-interactions 10 Mechanism-of-action 11 More General Terms 12 Additional Terms 13 Internet Database 14 References

More Specific Terms

• demeclocycline (Declomycin)
• doxycycline (Vibramycin, Doryx, Periostat, Oracea)
• minocycline (Minocin, Solodyn)
• oxytetracycline (Terramycin, Clinamycin)

Introduction

• Tradenames: Achromycin, Sumycin.

Indications

• treatment of infections caused by susceptible bacteria, including mycoplasma & chlamydia, spirochetes, rickettsiae & some protozoa
• stage 1 Lyme disease
• treatment of non gonococcal urethritis caused by Chlamydia trachomatis & Ureaplasma urealyticum
• used in combination with other agents for severe acne
• used in combination with other agents for Helicobacter pylori ( H pylori)

Contraindications

• pregnant women
• children
• avoid in ESRD
  

• pregnancy category = d
• safety in lactation = -

Dosage

• take on an empty stomach (food impairs absorption)
• 250-500 mg IV/ PO QID
• maximum dose is 1 g/day with hepatic insufficiency

• Tabs: 250 & 500 mg.
• Suspension: 125 mg/5 mL.
• Ophthalmic: 1-2 drops BID- QID PRN or ointment every 2-12 hours
• Ointment: 1% (3.72 g).
• Suspension: 1% (1 mL).

Dosage-adjustment-in-renal-failure

*   creatinine clearance             dosage 
*    50-80 mL/min                   8-12 hour dosing 
*    10-50 mL/min                  12-24 hour dosing 
*     < 10 mL/min                     24 hour dosing

Pharmacokinetics

• well distributed to most body tissues & fluids
• approximately 60% excreted unchanged in the urine
• hemodialysis removes 20-30%, 5-20% [6]
• peritoneal dialysis has no effect
• elimination 1/2life is 11 hours with normal renal function & 57-108 hours in anuric patients
• dose adjustment indicated for renal insufficiency
  

• elimination via liver
• elimination via kidney

Adverse-effects

• common (> 10%)

• discoloration of teeth & enamel hypoplasia (infants)

• less common (1-10%)

• nausea, diarrhea, photosensitivity

• uncommon (< 1%)

• increased intracranial pressure, bulging fontanels in infants, paresthesia, diabetes insipidus, vomiting, erosive esophagitis, anorexia, abdominal cramps, acute renal failure, azotemia, superinfections, pericarditis, anaphylaxis, pruritis, pigmentation of nails, exfoliative dermatitis, thrombophlebitis, pseudotumor cerebri, pseudomembranous colitis, staphylococcal enteritis, hepatotoxicity, renal damage, hypersensitivity reactions, candida superinfection

• other

• phototoxicity
• tooth deposition

Drug-interactions

• decreased absorption of tetracycline with:

• aluminum
• bismuth
• iron
• magnesium
• bicarbonate
• sucralfate

• decreased serum concentrations of tetracyclines when coadministered with:

• barbiturates
• carbamazepine
• hydantoins

• tetracyclines can increase serum concentration of:

• digoxin

• food & dairy products interfere with absorption of tetracycline
  
• drug interaction(s) of antibiotics with warfarin

Mechanism-of-action

• bacteriostatic
• inhibits bacterial protein synthesis
• inhibits matrix metalloproteinases ( matrixins)

More General Terms

• antibacterial agent

Additional Terms

• matrixin or matrix metalloproteinase

Internet Database

Kegg: [1]

References

1. The Pharmacological Basis of Therapeutics, 9th ed. Gilman et al, eds. Permagon Press/McGraw Hill, 1996
2. Harrison's Principles of Internal Medicine, 13th ed. Companion Handbook. Isselbacher et al (eds), McGraw-Hill Inc. NY, 1995, pg 164
3. Sanford Guide to antimicrobial therapy 1997
4. Drug Information & Medication Formulary, Veterans Affairs, Central California Health Care System, 1st ed., Ravnan et al eds, 1998
5. Prescriber's Letter 6(10):58, Oct, 1999
6. Kaiser Permanente Northern California Regional Drug Formulary, 1998

tetracycline (Achromycin, Sumycin, Bristacycline)