Dr. Qadria AL-Deab
Dr. Areej Altaweel
-a broad-spectrum antibiotics.
-It is commonly used to treat acne,
infection, and other infections caused by
-The first of these compounds was
chlortetracycline followed by
oxytetracycline and tetracycline.
Tetracycline divided into:
a) Naturally occurring:
Total Synthesis of the
Structure and chemical characteristics
Structure activity relationship
• R5 R4 R3 R2 R1.
Chlortetracycline H H OH CH3 Cl
Oxytetracycline H OH OH CH3 H
Tetracycline H H OH CH3 H
Demethylchlortetracycline H H OR H CI
Rolitetracycline + H OH CH3 H
Metacycline H OH CH2 H
Doxycycline H OH H CH3 H
Minocycline H H H N(CH3)2
• Retention of the configuration of the
asymmetric centres C-4, C-4a and C-12a is
essential, whereas the configurations at C-5,
C-5a and C-6 may be altered:
• 1- The amide hydrogen may be replaced
with a methyl group, but larger groups have
a deleterious effect except for those which
are eliIminated spontaneously in water .
• 2-The dimethyl amino group may be
replaced by a primary amino group
without loss of in vitro activity but all
other changes so far lead to decreased
bacteriostatic action .
• The hydrophobic part of the molecule
from C-5 to C-9 may be altered in
• modifications at C-6 and C-7 in
particular afford products having
greater chemical stability.
• increased antibiotic activity and more
• Dehydrogenation to form a double
bond between C-5a and C-11a
markedly decreases activity
• Polar substituents at C-5 and C-6
contribute decreased lipid versus water
solubility to the tetracycline
• . The drugs are amphoteric, meaning
they will form salts with both strong
acids and bases. Thus, they may exist
as salts of sodium or chloride.
-The tetracyclines are broad-spectrum
-They are active against the following
1_ gram-positive and gram-negative bacteria
6_ Candida albicans
12_ Campylabacter fetus
Mechanism of action:
Mechanism of resistance :
There are three types of tetracycline
Types of tetracyclines:
-treat cancer patients with SIADH.
-combined with hydrocortisone in a paste used
by dentists .
Dermatological:-Skin reactions, photosensitivity
GIT:-nausea, vomiting, and diarrhea.
Immune System:-allergic reactions.
Other:-yellowish-grayish-brown discoloration of the
-Absorption: ~50% to 80%.
-Protein binding: 41% to 50%
-Half-life elimination: 10-17 hours
-Time to peak, serum: 3-6 hours
-used as antibacterial and antiprotozoal agent.
-In veterinary medicine, it is commonly used
to treat conjunctivitis in cats.
-treat Spirochaetal infection.
-treating Clostridial wound infection and Anthrax.
-Local irritation after intramuscular injection.
-Gastrointestinal:-anorexia, nausea, vomiting.
-Hypersensitivity reactions: Urticaria.
-Blood: Hemolytic anemia, thrombocytopenia,
-Tetracycline's primary use is for the
treatment of acne vulgaris and rosacea.
-It is also used to treat a very wide range
-Gastrointestinal: anorexia, nausea,
-Skin: rashes, dermatitis.
Miscellaneous: Dizziness and headache
-typhus fever and Q fever.
-GI :Anorexia, nausea, vomiting, diarrhea.
-Hepatic toxicity: Hyperbilirubinemia.
-Blood:Agranulocytosis, hemolytic anemia.
-CNS: Convulsions, dizziness,sedation.
-Oral cavity discoloration.
-rapidly absorbed from the GIT.
-The peak plasma concentrations slightly
-serum half-life ranged from 11 to 16 hours in
hepatic dysfunction, and from 18 to 69 hours
with renal dysfunction.
used in the treatment of chronic adult
Drug interaction of tetracyclines::
antacids containing aluminum, Impaire the Absorption of
calcium, or magnesium, and tetracyclines
anticoagulant therapy Because tetracyclines have
been shown to depress plasma
prothrombin activity, patients
who are on anticoagulant
therapy may require downward
adjustment of their
bacteriostatic drugs interfere with the bactericidal
action of penicillin, it is
advisable to avoid giving
tetracycline-class drugs in
conjunction with penicillin.
oral contraceptives Concurrent use of tetracyclines
with oral contraceptives may
render oral contraceptives less
ergot alkaloids or their Increased risk of ergotism
derivatives are given with
Bile acid sequestrants May decrease tetracycline
Iron preparations May decrease absorption of
Methoxyflurane: when concurrent with
Methoxyflurane tetracycline) may
anesthes cause fatal
concurrent use is
Methotrexate: Clearance of
dose therapy) may be
TETRACYCLINES AVAILABLE IN THE UNITED STATES
Generic name Trade names Preparations
Demeclocycline Declomycin Oral
Doxycycline Vibramycin, Oral and
Doryx, Doxycin, parenteral
Minocycline Minocin Oral and
Oxytetracycline Terramycin Oral and
Tetracycline Achromycin V, Oral and