12.COMPREHENSIVE OFANTIMICROBIAL AGENTS AND CHEMOTHERAPY ( CLASSIFICATION AND MECHANISM)

BYBY
Dr.Dr. SAMINATHAN KAYAROHANAMSAMINATHAN KAYAROHANAM
M.PHARM, M.B.A, PhDM.PHARM, M.B.A, PhD
COMPREHENSIVE OF CHEMOTHERAPHY
(CLASSIFICATION AND MECHANISAM)
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III. MECHANISMS OF ANTIMICROBIAL AGENTS
1.INHIBITION OF CELL WALL SYNTHESIS
2.INHIBITION OF FUNCTIONS OF CELLULAR MEMBRANE
3. INHIBITION OF PROTEIN SYNTHESIS
4.INHIBITION OF NUCLEIC ACID SYNTHESIS
5.INHIBITION OF FOLIC ACID SYNTHESIS
CON ...
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BACTERIAL CELL STRUCTURE
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

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MECHANISMS OF ANTIBACTERIAL RESISTANCE
1.Inhibition of drug uptake or blocking the
entry (Change their cell membrane and cell
wall permeability to the drug)
2. Produce enzymes that destroy the chemical
structures of drugs
3.Alter or modified the target molecule.
4. Activation of drug efflux pump.
3

RESISTANCE TO ANTIBIOTICS
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A) TRANSFERMATION
When naked DNA (Antibiotic-resistance Gene) is released on
lysis of an organism and is taken up by another organism.
B) TRANSDUCTION
Antibiotic-resistance genes are transferred from one bacterium
to another by means of bacteriophages.
C) CONJUGATION
Direct contact between two bacteria:
Plasmids form a mating bridge across the bacteria and DNA is
exchanged, which can result in acquisition of antibiotic-
resistance genes by the recipient cell. Transposons can also
carry antibiotic-resistance genes
GENETIC TRANSFER

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VI. IDEAL ANTIMICROBIAL DRUG
Have highly selective toxicity to the pathogenic
microorganisms in host body
Have no or less toxicity to the host.
Low propensity for development of resistance.
Not induce hypersensitive in the host.
Have rapid and extensive tissue distribution
Be free of interactions with other drugs.
Be relatively inexpensive7

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VII. PREVENTION OF ANTIBIOTIC RESISTANCE
Patients :
•Take antibiotics exactly as the doctor prescribes.
•Do not skip doses.
•Complete the prescribed course, even when you feeling better.
•Only take antibiotics prescribed for you.
•Do not save antibiotics for the next illness.
•Discard any leftover medication once the treatment is completed.
•Do not ask for antibiotics to your doctor.
•Prevent infections by practicing hygiene and recommended vaccines.
Health professionals:
•Do not treat viral infections with antibiotics.
•Prescribe antibiotics only when they are absolutely necessary –
giving them at the right dose and only for as long as they are needed.
•Avoid unnecessary overlaps in antibiotics.
•Become familiar with resistance trends in your region.
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7.CLASSIFICATION OF CELL WALL INHIBITORS
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1.Natural Penicillins:
•Aqueous penicillin G
•Penicillin G
•Penicillin VK
2.Beta lacatamse resistant
Penicillins
•Methicillin
•Nafcillin
•Oxacillin
•Cloxacillin
•Dicloxacillin
3. Aminopenicillins
/extended spectrum
•Ampicillin
•Amoxicillin
4. Carboxypenicillins/
antipseudomonal
penicillins /extended
spectrum
•Carcenicillin
•Ticarcillin
5. Ureidopenicillins /
antipseudomonal
penicillins / extended
spectrum
•Mezlocillin
•Piperacillin
6. Penicillins/inhibitor
combination
•Ampicillin/sulbactam
•Ticarcillin/clavulanate
•Piperacillin/tazobactam
•Amoxicillin/clavulanate
8.CLASSIFICATION OF PENICILLIN
Con…Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

10. MECHANISM OF ACTION OF PENICILLINS
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1.Penicillin-binding proteins:
Penicillins inactivate numerous proteins on the bacterial cell membrane. These
penicillin-binding proteins (PBPs) are bacterial enzymes involved in the synthesis of
the cell wall and in the maintenance of the morphologic features of the bacterium.
2.Inhibition of transpeptidase:
Penicillins inhibit this transpeptidase-catalyzed reaction, thus hindering the formation
of cross-links essential for cell wall integrity. As a result of this blockade of cell wall
synthesis.
3.Production of autolysins:
Many bacteria, particularly the gram-positive cocci, produce degradative enzymes
(autolysins) that participate in the normal remodeling of the bacterial cell wall.

Con…
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4. CLASSIFICATION OF PROTEIN SYNTHESIS INHIBITORS

3. GENERAL MECHANISM OF ANTIBIOTIC
13 Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

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1) Effective against many organisms.
2) Well-absorbed orally.
3) Well-distributed in tissues.
4) Relatively long serum half-lives and minimal toxicity.
5) Deep-tissue and cell penetration.
6) Urinary tract infections, prostatitis.
7) Infections of the skin and bones.
8) Penicillin-resistant sexually transmitted diseases.
9) lower cost in synthesis with the excellent activities.
2. ADVANTAGES OF QUINOLONES

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4. CLASSIFICATION OF QUINOLONES

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7. MECHANISM OF QUINOLONES

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Con…
10.CLASSIFICATION OF SULFONAMIDE

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12. MECHANISM OF SULFONAMIDES AND TRIMETHOPRIM
Con…

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8. CLASSIFICATION OF ANTIMYCOBACTERIALS

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8. CLASSIFICATION OF ANTIMYCOBACTERIALS
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0
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40
60
80
100
120
一月二月三月四月
亚洲区
欧洲区
北美区
9. MECHANISM OF ANTIMYCOBACTERIALS
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9. MECHANISM OF ANTIMYCOBACTERIALS

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5.CLASSIFICATION

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6.SITES OF ACTION OF COMMON ANTIFUNGAL DRUGS
Con…
POLYENES
IMIDAZOLES
TRIAZOLE
ALLYLAMINES
OTHER
GLUCAN
SYNTHASE
INHIBITORS
BIND TO ERGOSTEROL
AND FORM PORES
(CHANNELS)

FLUCYTOSINE
IMIDAZOLES
TRIAZOLES
POLYENES
CANDINS
GRISEOFULVIN
OTHERS
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7. ANTI FUNGAL DRUGS MECHANISAM

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5.CLASSIFICATION OF ANTIVIRAL DRUGS
1
2
3

6.MECHANISM OF ANTIVIRAL AGENTS
27Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

8.HIGHLY ACTIVE ANTIRETROVIRAL (HIV) THERAPY (HAART)
28 4Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

9.DRUGS USED TO PREVENT HIV FROM REPLICATING
Con…29 Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

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6. ANTHELMINTIC DRUGS
roundworms
(flukes) are leaf-
shaped flatworms
tapeworms

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Diethylcarbamazine is used in the treatment of filariasis because of
its ability to immobilize microfilariae and render them susceptible to
host defense mechanisms.
 Combined with albendazole, diethylcarbamazine is effective in the
treatment of Wuchereria bancrofti and Brugia malayi infections.
It is rapidly absorbed following oral administration with meals and is
excreted primarily in urine.
Symptoms include fever, malaise, rash, myalgias, arthralgias, and
headache, and their severity is related to parasite load.
Most patients have leukocytosis. Antihistamines or steroids may be
given to ameliorate many of the symptoms.
6.1. DIETHYLCARBAMAZINE

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Ivermectin is the drug of choice for the treatment of
onchocerciasis (river blindness) caused by Onchocerca volvulus and
for cutaneous larva migrans and strongyloidiasis.
Ivermectin targets the parasite’s glutamate-gated chloride
channel receptors. Chloride influx is enhanced, and
hyperpolarization occurs, resulting in paralysis of the worm.
The drug is given orally. It does not cross the blood-brain barrier
and has no pharmacologic effects in the CNS.
Ivermectin is also contraindicated in pregnancy.The killing of the
microfilaria can result in a Mazotti-like reaction (fever, headache,
dizziness, somnolence, and hypotension).
6.2. IVERMECTIN

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 Mebendazole a synthetic benzimidazole compound, is
effective against a wide spectrum of nematodes.
 It is a drug of choice in the treatment of infections by
whipworm (Trichuris trichiura), pinworm (Enterobius
vermicularis), hookworms (Necator americanus and
Ancylostoma duodenale), and roundworm (Ascariasis
lumbricoides).
 Mebendazole acts by binding to and interfering with
the assembly of the parasites' microtubules and also
by decreasing glucose uptake. Affected parasites are
expelled with the feces.
 Mebendazole is relatively free of toxic effects, although
patients may complain of abdominal pain and diarrhea. It is,
however, contraindicated in pregnant women ,because it has
been shown to be embryotoxic and teratogenic in
6.3. MEBENDAZOLE

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Pyrantel pamoate along with mebendazole,
is effective in the treatment of infections caused by
roundworms, pinworms, and hookworms.

Pyrantel pamoate is poorly absorbed orally and exerts its
effects in the intestinal tract.
It acts asa depolarizing, neuromuscular-blocking
agent, causing persistent activation of the parasite’s
nicotinic receptors.
The paralyzed worm is then expelled from the host’s
intestinal tract. Adverse effects are mild and include nausea,
vomiting, and diarrhea.
6.4. PYRANTEL PAMOATE

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Thiabendazole another synthetic benzimidazole,is effective against
strongyloidiasis caused by Strongyloides stercoralis (threadworm),
cutaneous larva migrans, and early stages of trichinosis (caused by
Trichinella spiralis;
Thiabendazole, like the other benzimidazoles, affects microtubular
aggregation.
 Although nearly insoluble in water, the drug is readily absorbed on oral
administration.
It is hydroxylated in the liver and excreted in urine. The adverse effects
most often encountered are dizziness, anorexia, nausea, and vomiting.
There have been reports of central nervous system (CNS) symptomatology.
There have been a number of fatalities among the
cases of erythema multiforme and Stevens-Johnson syndrome
reportedly caused by thiabendazole. Its use is contraindicated during
pregnancy.
6.5. THIABENDAZOLE

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Trematode infections are generally treated with praziquantel. This drug is
an agent of choice for the treatment of all forms of schistosomiasis and
other trematode infections and for cestode infections like cysticercosis.
Permeability of the cell membrane to calcium is increased, causing
contracture and paralysis of the parasite.
Praziquantel is rapidly absorbed after oral administration and distributes
into the cerebrospinal fluid. High levels occur in bile. The drug is extensively
metabolized oxidatively, resulting in a short half-life.
Common adverse eff ects include drowsiness, dizziness, malaise, and
anorexia as well as gastrointestinal upsets. The drug is not recommended
for pregnant women or nursing mothers. Drug interactions due to
increased metabolism have been reported .
Praziquantel is contraindicated for the treatment of ocular cysticercosis,
because destruction of the organism
in the eye may damage the organ.
6.6. PRAZIQUANTEL

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 Broad spectrum
 Drug of choice for treatment of hydatid disease and
cysticercosis.
 Used for the treatment of ( intestinal nematodes )
e.g. ascariasis , tricurasis and strongyloidiasis,
pinworm, hookworm
 Inhibits microtubule synthesis that irreversibly
impairs glucose uptake , intestinal parasites are
immobilized and die slowly.
 larvicidal in : hydatid ,cysticercosis , ascariasis and
hook worm infections.
 Ovicidal in ascariasis ,hookworm , trichuriasis
6.7. ALBENDAZOLE

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Niclosamide is the drug of choice for most cestode
(tapeworm) infections.
Its action has been ascribed to inhibition of the
parasite’s mitochondrial phosphorylation of adenosine
diphosphate, which produces usable energy in the form
of adenosine triphosphate. anaerobic metabolism may
also be inhibited.
Alcohol should be avoided within 1 day of niclosamide.
6.8. NICLOSAMIDE

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4. CLASSIFICATION OF ANTIPROTOZOAL DRUGS

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6.LIFE CYCLE OF ENTAMOEBA HISTOLYTICA

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7.LIFE CYCLE OF THE MALARIAL PARASITE

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3. RISK FACTORS
1.Tobacco
2.Sunlight
3.Ionizing radiation
4.Certain chemicals and other substances
5.Some viruses and bacteria
6.Certain hormones
7.Family history of cancer
8.Alcohol
9.Poor diet, lack of physical activity, or being overweight

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categorized based on the functions/locations of the
cells from which they originate:
Carcinoma: a tumor derived from epithelial cells, those cells
that line the surface of our skin and organs (80-90% of all
cancer cases reported)
Sarcoma: a tumor derived from muscle, bone, cartilage, fat
or connective tissues.
Leukemia: a cancer derived from white blood cells or their
precursors.
Lymphoma: a cancer of bone marrow derived cells that
affects the lymphatic system.
Myelomas: a cancer involving the white blood cells
responsible for the production of antibodies (B lymphocytes)
6. CANCER TYPES

13.ANTI CANCER DRUG CLASSIFICATION
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14.CHEMOTHERAPEUTIC DRUGS AFFECTING RNA /DNA PRECURSORS.
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2.B. TYPE OF ACQUIRED IMMUNITY
Con…

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11. CLASSIFICATION OF
IMMUNOSUPPRESSANTS

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16.ACTION OF IMMUNOSUPPRESSANTS

12.COMPREHENSIVE OFANTIMICROBIAL AGENTS AND CHEMOTHERAPY ( CLASSIFICATION AND MECHANISM)

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