1.Introduction

2.Mechanish of action

3.Use

4.Pharmacokinetics

5.Side effect

6.Contraindicated

7.Monograph

1.Introduction

Tetracyclines is a group of antibiotics that include Tetracycline ; it was discovered in 1948 , exhibited activity against a wide range of microorganisms including gram - positive and gram - negative bacteria , Chlortetracycline was the first Tetracycline to be identified .. Since then five additional tetracyclines have been isolated or derived ( oxytetracycline , tetracycline , Demeclocycline , Doxycycline and minocycline ) 

2.Mechanism of action

Tetracycline inhibits bacterial protein synthesis by blocking the attachment of charged tRNA at the P site peptide chain, binding to the 30S and 50S subunits of microbial ribosomes.

This interference prevents the formation of a peptide chain, making tetracycline bacteriostatic. The drug's mechanism is reversible and not inhibitory even after drug withdrawal.

 Bacteria develop resistance through gene transfer encoding efflux pumps or ribosomal protection proteins, counteracting tetracycline's effects.

3.Use

Tetracycline is an antibiotic commonly used to treat a variety of bacterial infections. Here are some of its main uses and considerations

Common Uses:

Respiratory Tract Infections: Such as pneumonia and bronchitis.

Skin Infections: Including acne and rosacea.

Urinary Tract Infections (UTIs): Infections of the urinary tract.

Gastrointestinal Infections: Including Helicobacter pylori, which can cause ulcers.

4.Pharmacokinetics

Tetracycline has the following pharmacokinetic properties:

Absorption is variable and incomplete, ranging from 25-60% after oral administration34. Absorption is enhanced when taken on an empty stomach.

It is not significantly metabolized, with only 5% converted to a less active metabolite.

Tetracycline is primarily eliminated unchanged via renal excretion.

Tissue penetration is limited due to its low lipophilicity compared to later generation tetracyclines.

Bile concentrations are 10-25 times higher than serum levels.

High concentrations are also found in the kidneys, liver and intestines.

Factors like renal impairment can lead to excessive blood levels and potentially fatal acute fatty degeneration of the liver, especially in pregnancy.

5.Side effect

The most common side effects of tetracycline include:

Gastrointestinal issues like nausea, vomiting, diarrhea, anorexia, and esophageal irritation or ulcers (especially 

 when taken with little liquid before bedtime)

Increased sensitivity to sunlight, potentially leading to severe sunburns

Permanent teeth discoloration  in children under 8 years old

Skin rashes, hives, and photosensitivity

6.Contraindicated

Tetracycline is contraindicated in pregnancy due to hepatotoxicity and fetal tooth discoloration. It's also contraindicated in children under 8 years, except for severe illnesses when benefits outweigh risks. Tetracycline can cause increased intracranial pressure and is contraindicated with certain medications like acitretin and flibanserin. It's crucial to consult healthcare professionals before using tetracycline.