Tetracycline antibiotic in brief.

2.  Tetracyclines are broad-spectrum antibiotics
obtained from various species of
Streptomyces.
 These are having a nucleus of four cyclic
rings.
 The tetracyclines still available for clinical
use are:
Tetracycline
Doxycycline
Oxytetracycline
Minocycline
Demeclocycline

3. Tetracycline
Selectively taken up by susceptible organisms by
active transport
Compete with bacterial tRNA to bind 30S ribosome.
Inhibit bacterial protein synthesis

5.  Routes of absorption:
 Oral
 parenteral and
 topical.
 Absorption:
 Incomplete, irregular from the
gut.
 Distribution:
 Widely distributed in most
fluid compartments
 Can cross the placenta
 Appears in milk
 Execration:
 Renal route
 Non-renal ( faces, bile)
 Plasma half life:
 Tetracycline: 6hrs
 Doxycycline:16hrs
 Minocycline: 15hrs.

6. Tetracycline+ Antacid/ Milk
Cause: Antacids decrease git absorption by chelate
formation
Tetracycline+ Iron
Cause: Iron decrease absorption of tetracycline

7.  Children under age of 8 years.
 Pregnancy :
Early: Teratogenicity
Late: Foetal bone deformity
Hepatotoxicity
Discoloration of the teeth of offspring
 Nursing mother
 Renal failure
 Systemic Lupus Erythematosus (SLE).

8.  Irritative effects:
Oral ingestion: Epigastric pain,
nausea, vomiting and diarrhea
I.V. injection: Thrombophlebitis
 Hypersensitivity
Skin rashes,
urticaria,
glossitis,
Pruritus
 Organ toxicity:
Liver damage
Liver damage
Phototoxicity
Teeth and bones
Antianabolic effect
Increased intracranial pressure
Diabetes insipidus
 Superinfection

9. Tetracyclines are the first
choice drugs:
 Venereal diseases:
 Atypical pneumonia
 Cholera
 Brucellosis
 Plague
 Relapsing fever
 Relapsing fever:
Other situations in which
tetracyclines may be used are:
 Urinary tract infections
 Community-acquired pneumonia
 Amoebiasis
 Acne vulgaris
 Chronic obstructive lung disease
 As adjuvant to quinine or artesunate
for chloroquine-resistant P.
falciparum malaria