Слайд 1Antibiotics
having a β-lactam ring.
Слайд 2Antibiotics - antimicrobial substances of natural origin, produced by certain
types of fungi and bacteria. Usually they are used as
chemotherapy drugs.
There are antibiotics: antibacterial, antifungal, antineoplastic.
Depending on the method of obtaining: natural and semi-synthetic.
Слайд 3Classification (chemical structure):
β-Lactam antibiotics: Penicillins, Cephalosporins, Monobactams, Carbapenems;
Macrolide antibiotics:
Erythromycin, Clarithromycin, Azithromycin;
Tetracyclines: Oxytetracycline, Doxycycline;
Nitrobenzene derivative: Chloramphenicol;
Aminoglycosides: Streptomycin, Gentamycin,
Amikacin, Neomycin;
Lincosamide antibiotics: Lincomycin, Clindamycin;
Glycopeptide antibiotics: Vancomycin.
Слайд 4Mechanism of action:
Inhibit cell wall synthesis: Penicillins, Cephalosporins, Vancomycin,
Cause leakage
from cell membranes: Polymyxins, Polyenes—Amphotericin B, Nystatin;
Inhibit protein synthesis: Tetracyclines,
Chloramphenicol, Erythromycin, Clindamycin,
Cause misreading of m-RNA code and affect permeability: Aminoglycosides;
Interfere with DNA function: Rifampicin
Слайд 6Type of antimicrobial action:
Bactericidal (complete destruction of bacterial cells)
Bacteriostatic (stopping of the growth and division of bacterial cells)
Spectrum
of activity:
Narrow-spectrum: Penicillin G, Erythromycin
Broad-spectrum: Tetracyclines, Chloramphenicol
Слайд 8Toxicity and side effects:
Practically all AMA, especially erythromycin, tetracyclines, certain
cephalosporins and chloramphenicol are irritant.
Systemic toxicity: Almost all AMAs produce
dose related and predictable organ toxicities. Some have a high therapeutic index—doses up to 100-fold range may be given without apparent damage to host cells. These include penicillins, some cephalosporins and erythromycin.
Others have a lower therapeutic index—doses have to be individualized and toxicity watched for, e.g.:
Aminoglycosides: 8th cranial nerve and kidney toxicity.
Tetracyclines: liver and kidney damage.
Chloramphenicol: bone marrow depression.
Слайд 9Others have a very low therapeutic index— use is highly
restricted to conditions where no suitable alternative is available (Polymyxin
B, Vancomycin, Amphotericin B)
Practically all AMAs are capable of causing hypersensitivity reactions. These are unpredictable and unrelated to dose.
Drug resistance (Natural resistance, Mutation, Gene transfer, Cross resistance)
Superinfection (Suprainfection).
Слайд 10PENICILLIN was the first antibiotic to be used clinically in
1941.
Chemical structure of penicillins:
Thiazolidine ring;
β-lactam ring;
Слайд 11Ps. inhibit synthesis of the bacterial cell wall. The cell
wall is composed of a polymer called peptidoglycan that consists
of glycan units joined to each other by peptide cross-links.
Ps. inhibit transpeptidase, but activate production of autolysins
Ps. interfere with the last step of bacterial cell wall synthesis (transpeptidation or cross-linkage). Cell lysis can then occur, either through osmotic pressure or through the activation of autolysins. The type of action is bactericidal.
Слайд 13Classification
Biosynthetic ps:
A. For parenteral use:
Short acting: Benzylpenicillin
Long acting: Procaine-benzylpenicillin,
Benzylpenicillin-benzatine (bicilline 1), Bicilline-5
For oral use (acid-stable): phenoxymethylpenicillin
Слайд 14Antibacterial spectrum of biosynthetic ps.:
Cocci: Streptococci, Pneumococci, Staphylococci, Neisseria gonorrhoeae
and N. meningitidis;
B. anthracis, Corynebacterium diphtheriae,
Clostridia (tetani and others),
Listeria,
spirochetes (Treponema pallidum, Leptospira),
Actinomyces
Staph. Aureus produces penicillinase (a narrow spectrum β-lactamase which opens the β-lactam ring and inactivates Ps)
Слайд 16Benzylpenicillin is injected I.M. and I.V. 4-6 times a day.
It penetrates well into the tissues, through BBB only in
inflammation. It is excreted by the kidneys in the active form.
Bicillins are poorly water soluble salts, they are administered only I.M. They are long-term acting drugs.
Phenoxymethylpenicillin is acid-stable, its bioavailability is 30-60%. It is less active. It is used for respiratory infections.
Слайд 18Uses:
Streptococcal infections (pharyngitis, otitis media, scarlet fever, rheumatic fever)
Pneumococcal
infections
Meningococcal infections (meningitis)
Gonorrhoea
Syphilis, Leptospirosis
Diphtheria
Tetanus and gas gangrene
Prophylactic uses (Benzathine penicillin
- bicillins): rheumatic fever, bacterial endocarditis
Слайд 19Classification of semysinthetic ps.
Penicillinase-resistant penicillins: Methicillin, Oxacillin, Cloxacillin, Dicloxacillin.
Extended spectrum
penicillins
a) Aminopenicillins: Ampicillin, Amoxicillin.
b) Act on Pseudomonas aeruginosa: Carbenicillin, Ticarcillin,
Piperacillin, Mezlocillin.
β-lactamase inhibitors: Clavulanic acid, Sulbactam, Tazobactam
Слайд 21Oxacillin, Cloxacillin, Dicloxacillin are highly penicillinase and acid resistant. Activity
against PnG sensitive organisms is weaker. They do not effect
on Treponema and Borrelia.
They are incompletely absorbed from oral route, especially if taken in empty stomach. Elimination occurs primarily by kidney, also partly by liver. They are administered 4-6 times a day p/o, IV, IM.
Uses: staphylococcal infections.
Слайд 22Ampicillin, Amoxicillin inhibit H. influenzae, E. coli, Proteus, Salmonella, Shigella
and Helicobacter pylori. They are active against all organisms sensitive
to PnG (except treponema). They are destroyed by penicillinase and inactive against staphylococci
They are absorbed from GIT (absorption of amoxicillin is better). They are eliminated by kidneys and they are partly excreted in bile and reabsorbed—enterohepatic circulation occurs.
Ampicillin is used 4-6 times a day,
Amoxicillin – 3 times a day.
Слайд 23Uses:
Urinary tract infections;
Respiratory tract infections: including bronchitis, sinusitis, otitis media;
Gonorrhoea;
Bacillary
dysentery;
Cholecystitis;
H. pylori-infections (ulcer)
Septicaemias and mixed infections
Слайд 24Carbenicillin, Ticarcillin, Piperacillin, Mezlocillin are active against Pseudomonas aeruginosa and
indole positive Proteus, Bacteroides, many Enterobacteriaceae, Klebsiella,.
They are neither penicillinase-resistant
nor acid resistant. They are inactive orally and are excreted rapidly in urine. They are used 4-6 times a day.
Uses: serious infections caused by Pseudomonas or Proteus, e.g. burns, urinary tract infection, septicaemia.
Слайд 25Combination of drugs with inhibitors of β-lactamases (clavulanic acid, sulbactam,
tazobactam): amoxicillin + clavulanic acid
Clavulanic acid has a structural similarity
with penicillins and it is subject to destruction. Antibiotic retains its structure.
Uses: skin and soft tissue infections, intraabdominal and gynaecological sepsis, urinary, biliary and respiratory tract infections.
Слайд 26Allergic reactions (urticaria,
anaphylactic shock, fever, dermatitis)
Irritant effect (gingivitis, stomatitis,
dyspepsia, phlebitis, infiltrates)
Neurotoxicity (seizures)
Dysbacteriosis, superinfection
Resistance of microorganisms
Thrombosis and embolism (bicillin)
Carboxypenicillins
and Ureidopenicillins: violation of blood (leukopenia, thrombocytopenia), interstitial nephritis, disorders of coagulation
Слайд 27The cephalosporins are β-lactam antibiotics. Most cephalosporins are produced semisynthetically
by the chemical attachment of side chains to 7-aminocephalosporanic acid.
They
act bactericidally; inhibit transpeptidase, disrupt the synthesis of peptidoglycan, violate the synthesis of the cell wall.
Слайд 28The first-generation cephalosporins act as Pn G. They are resistant
to the staphylococcal penicillinase and also have activity against Proteus
mirabilis, E. coli, and K. pneumoniae. These drugs are destroyed by cephalosporinase.
Cephalexin (p/o), cefazolin (IM,IV) pass into the tissues, go through the BBB poorly, they are excreted by the kidneys by tubular secretion, appointed 3-6 times a day.
Слайд 29The second-generation cephalosporins display greater activity against three additional gram-negative
organisms: H. influenzae, Enterobacter aerogenes, and some Neisseria species, whereas
activity against gram-positive organisms is weaker.
Cefuroxime, cefaclor pass through the BBB in inflammation. They are excreted by the kidneys by filtration. They are appointed 3 times a day.
Слайд 30Cefotaxime, ceftriaxone, ceftazidime, cefixime -drugs of 3 generation are less
potent than first-generation cephalosporins against MSSA, have enhanced activity against
gram-negative bacilli. They act on Pseudomonas aeruginosa, Bacteroides, they are resistant to cephalosporinase.
They distribute very well into body fluids.
Adequate therapeutic levels in the CSF, regardless of inflammation, are achieved.
They are administered 1-2 times a day.
Слайд 314: Cefepime. Cefpirome.
The spectrum is very wide (gram-negative and
gram-positive), they are resistant to β-lactamases, but do not act
on Bacteroides.
They are administered IM, IV 2-4 times a day. They do not pass through the BBB. They are excreted by kidneys.
Слайд 325. Ceftaroline and Ceftobiprole are active against MRSA and used
for the treatment of serious infections. They are injected IV
2-3 times a day.
Слайд 33Uses:
Respiratory, urinary and soft tissue infections caused by gram-negative
organisms, especially Klebsiella, Proteus, Enterobacter, Serratia;
Penicillinase producing staphylococcal infections;
Septicaemias caused
by gram-negative organisms;
Surgical prophylaxis;
Meningitis;
Gonorrhoea;
Mixed aerobic-anaerobic infections;
Infections of GIT
Слайд 34Side effects:
Allergic reactions: rash, anaphylactic shock;
Local irritant effect: infiltrates,
phlebitis, dyspeptic disorders;
Nephrotoxicity (1 generation);
Neurotoxicity (nystagmus, hallucinations, seizures);
Hematotoxicity (thrombocytopenia, neutropenia,
reduction of blood clotting);
Alcohol intolerance(diarrhea, nausea, tachycardia, redness of the face);
Dysbacteriosis. Diarrhoea.
Слайд 35MONOBACTAMS - Aztreonam
Spectrum: gram-negative enteric bacilli, H.influenzae, Pseudomonas.
Aztreonam is
resistant to the action of most β-lactamases.
It is administered IV
and IM.
Side effects: phlebitis, skin rash, abnormal liver function tests.
This drug may be a safe alternative for treating patients who are allergic to other penicillins, cephalosporins, or carbapenems.
Слайд 36CARBAPENEMS
Imipenem-cilastatin, Meropenem
Spectrum: gram-positive cocci, Enterobacteriaceae, Ps. aeruginosa, Listeria, Bact.
fragilis., Cl.difficile.
They are resistant to most β-lactamases; inhibit penicillinase producing
staphylococci.
Uses: serious hospital-acquired respiratory, urinary, abdominal, pelvic, skin and soft tissue infections.
Side effects: nephrotoxicity, diarrhoea, vomiting, skin rashes and other hypersensitivity reactions.
Слайд 37The macrolides are a group of antibiotics with a macrocyclic
lactone structure to which one or more sugars are attached.
1
generation - Erythromycin
2 generation - Clarithromycin, Roxithromycin, Spiramycin, Josamycin
3 generation (azalid) - Azithromycin (Sumamed)
Type of action – bacteriostatic.
Слайд 38The macrolides bind irreversibly to a site on the 50S
subunit of the bacterial ribosome, thus inhibiting translocation steps of
protein synthesis. They may also interfere with other steps, such as transpeptidation.
Слайд 39Erythromycin is active against:
Str. pyogenes and Str. Pneumoniae, N.
gonorrhoeae, Str. viridans, N. meningitidis
Mycoplasma, H. influenzae, B. pertussis,
Clostridia, C. diphtheriae and Listeria,
Campylobacter, Legionella, Rickettsiae
Gardnerella vaginalis
Chlamydia trachomatis
Слайд 402 generation has activity similar to erythromycin, but it is
also effective against Haemophilus influenzae, Helicobacter pylori, Moraxella, Legionella, Mycoplasma
pneumoniae, toxoplasms.
Azithromycin: H. influenzae, Mycoplasma, Chlamydia pneumoniae, Legionella, Moraxella, Campylobacter, Ch. trachomatis, Mycobacterium avium, N. gonorrhoeae.
Слайд 41They are absorbed from the gastrointestinal tract, pass well into
the tissue. They do not pass through the BBB They
are excreted partially by the kidneys, partly by the liver (the bile).
They are used: Erythromycin 4-6 times a day.
2 generation-2 times a day.
Azithromycin is captured by leukocytes, passes with them into the focus of inflammation.
Its concentration is higher in the focus of inflammation than that in the blood.
It is eliminated slowly from the focus of inflammation and the body and used once a day.
Слайд 42Uses:
Bronchitis, tonsillitis, otitis, sinusitis, diphtheria;
Diseases of soft tissues (erysipelas,
mastitis),
Conjunctivitis,
Pneumonia caused by chlamydia, Mycoplasma, Legionella, Moraxella),
Sexually transmitted infections (syphilis,
gonorrhea),
Urogenital infection (prostatitis, adnexitis, urethritis, vaginitis).
Cholecystitis, cholangitis.
Ulcer.
Слайд 43Side effects:
Dyspeptic disorders (nausea, vomiting, diarrhea),
Stomatitis, gingivitis,
Cholestasis, liver dysfunction,
Allergic reaction,
Arrhythmias,
Deafness.
Слайд 44Literature
1. Tripathi K.D. Essentials of Medical Pharmacology. Eighth Edition. -2019.-
Jaypee Brothers Medical Publishers. The Health Sciences Publisher. -New Delhi.
London. Panama
2. D.A.Kharkevich. Pharmacology. Textbook for medical students. Translation of 12th edition of Russion textbook “Pharmacology” (2017). – М., ГЭОТАР-Медиа, 2017.
3. Review of pharmacology. Gobind Rai Garg, Sparsh Gupta. 13th edition. - 2019.- Jaypee Brothers Medical Publishers. The Health Sciences Publisher. -New Delhi. London. Panama
4. Whalen Karen. Lippincott Illustrated Reviews: Pharmacology. Sixth Edition. - Wolters Kluwer. - 2015.-Philadelphia
5. Color Atlas of Pharmacology. 2nd edition, revised and expanded. Heinz Lüllmann.- 2000 Thieme
6. Pharmacology Examination & Board Review. Tenth Edition. Trevor Anthony J., Katzung Bertram G., Kruidering-Hall Marieke, Susan B. Masters. - a LANGE medical book. - 2013.-New York
7. Medical Pharmacology at a Glance. Eighth Edition. Neal Michael J. – 2016. John Wiley & Sons, Ltd.
8. USMLE Step 1. Lecture Notes. Pharmacology. Lionel P.Raymon and others.- Kaplan Medical.Inc. -2009