This document defines various types of anti-infective agents and provides examples of each. It discusses antibiotics such as penicillins, cephalosporins, macrolides, quinolones, tetracyclines, and aminoglycosides. It also covers antiviral drugs, antifungal agents, antiparasitic drugs, and anti-tuberculosis agents. For each class, it provides the definition, examples of drugs, and their mechanisms and uses.
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Unit 6 Anti-Infective agent.pdf
1. Unit 6 : Anti-Infective Agents
HCSP 1232 Intro to Pharma
Roszan Sapon
2. Objective
• Definition, class, mode of action and
example of drug ;
• Anti-infective
• Antibiotic
• Antiviral
• Antifungal
• Antiparasites
3. Some terminology
• Pathogen: Disease causing microorganism.
• Empiric: Therapy that is started based upon on
experience and precedent in the observation
and treatment of disease.
• Normal flora: Organisms found in various parts
of the body living symbiotically.
• Aerobic: Requires oxygen to survive.
• Anaerobic: Does not require oxygen to survive.
4. • Gram Stain: Laboratory test used to determine
if an organism is gram-positive or gram-
negative.
• C & S: Culture and sensitivity. Determines the
organism present in the culture and the
antibiotic to which it is sensitive (susceptible to).
• Fungicide / fungistatic: To kill fungus
• Mycosis: Disease cause by fungus
Some terminology - cont
5. Definition
• Anti-infective : An agent that is capable of
acting against infection, either by inhibiting the
spread of an infectious agent of by killing the
infectious agent outright.
• Antibiotic: Substance that kills microorganism
growth (mostly bacteria).
• Antiviral : Class of medication used for treating
viral infections
• Antifungal : Pharmaceutical fungicide used to
treat and prevent mycosis
• Antiparasites : Drugs used to treat parasitic
diseases.
7. 1. Antibiotic
• An antibiotic is a type of anti-infective substance
active against bacteria.
• It is the most important of antibacterial agent for
fighting infection.
• Widely used in treatment and prevention of such
infection.
• Bacteriostatic: Inhibits replication of
microorganisms and prevents growth. Does not
kill bacteria.
• Bacteriocidal: Kills the bacteria.
8. Antibiotic - Mode of action
• Mode of action :
• They may either kill or inhibit the growth of
bacteria.
• Bacteriostatic: Inhibits replication of
microorganisms and prevents growth. Does
not kill bacteria.
• Bacteriocidal: Kills the bacteria. Its may
attack he structures of the microb including
their nucleus.
11. Antibiotics - Penicillins
• In 1928, Alexander Fleming noted that mold
belonging to the genus Penicillium inhibited the
growth of bacteria. Fleming called this unknown
antibacterial substance penicillin. Ten years later, a
group at Oxford University began to investigate
penicillin in laboratory mice. Penicillin was hailed as
a miracle drug and saved countless lives in World
War II
• Penicillins are antibiotics used to treat bacterial
infections that are derived from the antibiotic
penicillin.
12. Uses for Penicillin
• Penicillin antibiotics are used to treat many
types of infections caused by susceptible
bacteria. They are used to treat infections of
the middle ear, sinuses, stomach and
intestines, bladder, and kidney. They also are
used for treating
• pneumonia,
• blood infections (sepsis),
• uncomplicated gonorrhea,
• meningitis,
• endocarditis, and
• other serious infections.
13. • Penicillin V
• Penicillin G (P
fi
zerpen, Permapen)
• Amoxicillin/clavulonate (Augmentin)
• Ampicillin (Unasyn)
• Nafcillin (Nallpen)
• Oxacillin (Bactocill)
• Dicloxacillin
• Cloxacillin
Example of penicillin antibiotics
14. Antibiotics - Cephalosporins
• Cephalosporins are a large group of antibiotics derived from
the mold Acremonium (previously called Cephalosporium).
• Cephalosporins are bactericidal (kill bacteria) and work in a
similar way to penicillins.
• They bind to and block the activity of enzymes responsible
for making peptidoglycan, an important component of the
bacterial cell wall.
• They are called broad-spectrum antibiotics because they
are effective against a wide range of bacteria.
15. Use for Cephalosporins
• Cephalosporins may be used to treat infections
caused by susceptible bacteria, such as:
• Bone infections
• Ear infections (eg, otitis media)
• Skin infections
• Upper respiratory tract infections
• Urinary tract infections.
Cephalosporins are not usually used as a
fi
rst-
choice antibiotic. They tend to be reserved for
use when other antibiotics (often penicillins)
cannot be used.
16. Example of Cephalosporins
• There are currently five “generations” of
cephalosporins, with each generation
differing slightly in their antibacterial
spectrum (ie, how effective they are at
killing certain types of bacteria).
• Within each generation, there are
differences in terms of administration
(such as oral or intravenous
administration), absorption, excretion,
and how long the activity of the
cephalosporin lasts for in the body.
17. Example of Cephalosporins - cont
• Ancef and Kefazol (cefazolin)
• Ceclor and Cefaclor (cefaclor)
• Cefdinir.
• Ceftin and Zinacef (cefuroxime)
• Duricef (cefadroxil)
• Keflex and Keftabs (cephalexin)
• Maxipime (cefepime)
• Rocephin (ceftriaxone)
18. Antibiotics - Macrolides
• Macrolide: One in a class of antibiotics that includes
Biaxin (Clarithromycin), Zithromax (Azithromycin),
Dificid (Fidoximycin), and Erythromycin.
• The macrolides inhibit the growth of bacteria and are
often prescribed to treat rather common bacterial
infections.
• In more technical terms, the macrolides are a group of
antibiotics produced by various strains of
Streptomyces (spore forming bacteria that grow slowly
in soil or water as a branching filamentous mycelium
similar to that of fungi) and have a complex chemical
(macrocyclic) structure. They act by inhibiting protein
synthesis, specifically by blocking the 50S ribosomal
subunit. They are broad spectrum antibiotics.
19. Antibiotics - Quinolones
• A quinolone antibiotic is a member of a large group
of broad-spectrum bacteriocidals that share a bicyclic
core structure related to the substance 4-quinolone.
• They are used in human and veterinary medicine to
treat bacterial infections, as well as in animal
husbandry.
• Nearly all quinolone antibiotics in use are
fluoroquinolones, which contain a fluorine atom in
their chemical structure and are effective against
both Gram-negative and Gram-positive bacteria.
• One example is ciprofloxacin, one of the most widely
used antibiotics worldwide.
20. Antibiotics - Tetracyclines
• Tetracyclines have a broad spectrum of activity
against many gram-positive and gram-negative
bacteria as well as Mycoplasma, Chlamydia,
Rickettsiae, Plasmodia, and amoebae.
• They are usually bacteriostatic.
• Tetracyclines bind reversibly to the small subunits of
bacterial (and eukaryotic) ribosomes where they
interfere with binding of charged-tRNA to the
"Acceptor" site.
• Tetracyclines can also inhibit protein synthesis in the
host, but are less likely to reach the concentration
required because eukaryotic cells do not have a
tetracycline uptake mechanism.
21. Use of Tetracyclines
• Tetracyclines are used widely in both human and veterinary
medicine; for example, tetracyclines have been used:
• For the prevention of malaria
• For the treatment of moderate-to-severe acne or rosacea
• To treat anthrax
• To treat infections of the eye, gastrointestinal tract,
genitourinary tract, gums, respiratory tract, and skin
• To treat infections caused by lice, mites, or ticks (such as
Rocky Mountain spotted fever, typhus fever)
• To treat infections caused by Campylobacter, Chlamydiae,
Yersinia pestis (plague), Vibrio cholerae (cholera) and other
atypical organisms
• To treat respiratory tract infections caused by Mycoplasma
pneumoniae
• As a growth promoter in animals.
22. Use of Tetracyclines
• Because many strains of microorganisms are now
resistant to some tetracyclines, culture and susceptibility
testing is recommended before beginning treatment.
• Doxycycline is a tetracycline that may be considered
when penicillin is contraindicated.
23. Antibiotics - Aminoglycosides
• Aminoglycosides are natural or semisynthetic antibiotics
derived from actinomycetes.
• Aminoglycosides are potent, broad-spectrum antibiotics
that act through inhibition of protein synthesis.
• They are commonly used in combination with drugs
such as ampicillin.
• For example, gentamicin, an aminoglycoside antibiotic
that has gram-negative coverage, is used in
combination with both an agent against gram-positive
organisms and one that covers anaerobes. Because of
their potential nephrotoxicity, aminoglycosides should
be reserved as a last resort, for use in resistant or life-
threatening infections.
• In addition, aminoglycosides should be avoided during
pregnancy.
24.
25.
26. 2. Anti-Viral Agents
• Antiviral drugs are a class of medication used for
treating viral infections.
• Most antivirals target specific viruses, while a
broad-spectrum antiviral is effective against a
wide range of viruses.
• Unlike most antibiotics, antiviral drugs do not
destroy their target pathogen; instead they inhibit
its development.
27. Anti-viral
• Most of the antiviral drugs now available are
designed to help deal with
• HIV,
• herpes viruses,
• COVID-19,
• the hepatitis B and C viruses, and
• influenza A and B viruses.
• Researchers are working to extend the range of
antivirals to other families of pathogens.
28. Anti-viral
• Mechanism of Action (in combination or single
action)
• Inhibit viral attachment
• Prevent genetic copying of virus
• Prevent viral protein production, vital for
reproduction of virus.
30. Example of Anti-viral
• Antiherpesvirus
• acyclovir and ganciclovir
• Anti-influenza
• Amantadine and rimantadine Zanamivir, peramivir, and
oseltamivir
• Anti-HIV
• zidovudine, didanosine, zalcitabine, lamivudine, and
stavudine
• Anti Respiratory syncytial virus (RSV)
• Ribavirin
• Inteferon
• Represent a group of nonspecific antiviral proteins
produced by host cells in response to viral infections
31. 3. Anti-Fungal Agent
• Pharmaceutical fungicide used to treat and
prevent mycosis
• Fungi include mushrooms, yeasts & molds.
• Fungal infections or mycosis occur in
immunocompromised patients.
• Common examples include athlete's foot, ringworm.
• Histoplasmosis capsulatum, Aspergillosis,
Blastomycosis, & Candida albicans (oral thrush).
• Mode of action;
• killing the fungus
• preventing the fungus from growing
32. Example of Anti-Fungal drug
• Amphotericin
• Clotrimazole
• Fluconazole
• Griseofulvin
• Itraconazole
• Ketonazole
• Metronidazole
• Micronazole
• Nystatin
• Terbination
33. 4. Anti-parasites agent
• Antiparasitic drugs are a group of medications
used in the management and treatment of
infections by parasites, including protozoa,
helminths, and ectoparasites.
• Antiparasitic drugs include several classes of
drugs that cover a broad range of diseases
caused by parasites.
• Some common protozoa infections are malaria,
leishmaniasis, trypanosomiasis, amebiasis,
gardiasis and trichomoniasis.
•
34. Mode of action - Anti-parasites
• Anti malarial drugs differ depending on chemical
family to which they belong
• The 4-aminoquinoline deriatives work by inhibiting
deoxyribonucleic acid and ribonucleic acid
polymerase, enzymes essential to DNA and RNA
synthesis by the parasite cells.
35.
36. NON-AEROSOLIZED ANTI-INFECTIVE
DRUGS ANTI-TUBERCULOSIS AGENTS
• The standard approach to treating tuberculosis
(TB) today consists of multiple first line drugs
for a period of either 6 or 9 months.
• First line drugs are:
• Rifapentine
• Isoniazid
• Rifampin
• Ethambutol
• Pyrazinamide
• Streptomycin used to be a front-line drug, but has been
replaced by Rifapentine.
37. NON-AEROSOLIZED ANTI-INFECTIVE
DRUGS ANTI-TUBERCULOSIS AGENTS
• 9 Month approach
• Isoniazid and Rifampin are given for 9 months and in an initial
2 to 8 week period these two drugs are supplemented with one
of the other first line drugs.
• 6 Month approach
• Four drugs are used for 2 months followed by 4 months of
Isoniazid and Rifampin.
• There is an association of TB and HIV infection.
• Along with the disturbing increase in the number of TB
cases in conjunction with AIDS, there has been an
emergence of drug resistant strains of TB. The cure
rate is poor in this subset.
