Antibiotics Flashcards
B- Lactams
Spectrum: G+ cocci, bacilli
Not active on G- bact (except the sythetic ones)
Actions: on actinomycetes and spirochetes
Penicilin and ce`phalosporine are bactericidal
Side efffects on pencilin: high doses are neurotoxic (SNC)
AMYNOGLICOSIDES
Associated to B-lactamos
active on G+ and G-
More active on acid alcohol resistant bacillus
Mode of action: Bactericidal in the multiplication and resting phase bacteria
Side effects: neurotoxic (cranial nerve pait VII) and nephrotoxic (during renal elimination -> degenerative process)
Side effect on streptomycin: affects vestibular branch, balance problems
Side effect on dihydrostreptomycin: alters cochlear branch-> deafness or decreased hearing capacity
Macrolides
SPECTRUM: More active on : G+ cocci and bacilli Less active over: G- cocci and G- bact More: actynomices, mycoplasma, protozoa Action: bactericidal or bacteriolytic (depends on the dose) Indications: respiratory, genitourinary, enteritis Farmacs: - Erythromycin lactobionate - Erythromycin Thyocinate - Tylocin
Sinergistine
cocci G+ and G- and G+ bacilli
NOT ACTIVE over G- bacilli
Acts on actinomycete, mycoplasma and some protozoa
Cyclic Polypeptides
Structure: amino acids and a fatty acid
Side effects: extremely toxic
Head pf series: Polymyxin (A, B, C, D, E)
Action: bactericidal or bacteriostatic (regardless of the development stage of the bact)
Active on (spectrum): G-. E.coli, pseudomonas
Farmac:
- Bacitracin: bacteriostatic, cocci G+ and G- and G+ bact
Tetracyclines
Wide Spectrum: cocci (G+ and -), rickettsiae, spirochetes, mycoplasmas, actinomycetes, some protozoa
Action: bacteriostatic (by chelating metals that are necessary for the development and multpl of the bact)
SIde effects: Hepatotoxic (degenerativ phenomena on hepatocytes) specially when using chlortetracycline
Chloramphenicol
Mode of action: bacteriostatic (cannot b associated w b- lactams)
Side effects: in high doses / long ttmnts-> degenerative process on hematopoietic organs (bone marrow)
Spectrum: wide (Cocci both, bacillus both…)
Crosses the HEB
Metab by feces, kidney and bile
Esters of Penicilin G
Association w:
- crystalized penicilin G
- crystialine penicillin G
- procaine penicillin (tripedine, propamicin)
Example: Benzathine peniciline, procaine peniciline (ester of benzyl penicilin G)
The antibiotic base: the quantity of a pure antibiotic, w/out taking into account its actual salt
Ampicillin
Semisynthetic penicilin
Spectrum: wide (max action on G- bacilus)
Adm (oral/parenteral)
Ticarcillin
Semisynthetic Penicilin
Spectrum: (aerobic and anaeribic G+ and -)
Cephalosporines
Structure: contains b-lactames ring More resistant to b-lactamases produced by staphilococcus, They can have_ - Total resistance to all lactamases - Resistant to one or more lactamases - No resistance
Classes of cephalosporins:
- Extraction
- Semisynthetic
- Synthetic
Pharmacokinectics of Cephalosporines
Great diffusion
Good penetration in parenchima, pleura, peric, synovialis
Bad penetration: eyes, CSF
Last gen penetrates HEB
Mode of action: bactericidal (mechanismo similiar to penicilins)
1st Gen Cephalosporines
Spectrum:
- Great action: G+ bact and G+ cocci
- Avarage action: G-cocci (more intensive in staphylococcus)
Restricted act: Gram - bact
2nd gen cephalosporines
Action: G+ bact
Active: G-: E.coli, Proteus, Klebsiella, Pasteurella, Salmonella
Very active against: Indole + species (Proteus)
Resistance: Citro and Enterobacter and P.aeuriginosa
2nd gen cephalosporines
Action: G+ bact
Active: G-: E.coli, Proteus, Klebsiella, Pasteurella, Salmonella
Very active against: Indole + species (Proteus)
Resistance: Citro and Enterobacter and P.aeuriginosa
2nd gen cephalosporines
Action: G+ bact
Active: G-: E.coli, Proteus, Klebsiella, Pasteurella, Salmonella
Very active against: Indole + species (Proteus)
Resistance: Citro and Enterobacter and P.aeuriginosa
2nd gen cephalosporines
Action: G+ bact
Active: G-: E.coli, Proteus, Klebsiella, Pasteurella, Salmonella
Very active against: Indole + species (Proteus)
Resistance: Citro and Enterobacter and P.aeuriginosa
3rd gen cephalosporines
Spectrum:
- The widest (representative against P. aureginosa)
- Weaker action against G+
- Stronger against: G-
- Active against: pseudomonas, B. bronchioseptica
Side effects cephalosporines
Consideren non - toxic High doses: hepatotoxic and nephrotoxic (human) In animals irritation on th injection site Recommended in: - Resp infec - Excret systm infec -Osteomyelitis Mastitis
Cefiotour
(Cephalosporin)
Mode of action: inhibition of the bacterial wall synthesis
Spectrum: wide (effective on most germs) (not active against mycoplasma)
Comercial: Vetimast (cefacetril), Pathozone, Excenel (ceftiofur)
Side effects: the ones in general
Rifampicin (A, B, C, D)
Mode of action: bactericidal or bacteriostatic
Spectrum: wide, resistant to digestive juices. Acts on G+
Not toxic to the eight cranial pair
Intervenes on general enteric infec
Antagonist: Penicilin and tetracyclines
Elim: feces and urine
Bacitracin
Cyclic Polypeptide
Action: bacteriostatic (bactericidal) G+ and - cocci and G+ bact
Mix of 4 polypeptides: A, B, C, F
Batracin A is more used in vet
Solvocilin
Tetracycline
Injectable
Widely used
Doxycycline
Tetracycline Semisynthetic Comercial: Dizenter Most active Associanted w vit K3 Ttmt of : dysentery and enteritis
Clortetrasol
Tetracycline
Tto: bronchoneumonia, sepsis in newborns, arthritis, mastitis
Mix of: tretracycline, chloramphenicol, prednisolone acetate and lidocaine
Terapentane T
Tetracycline
GET in calves
Mix of: aureloin, oxychinolein, gallin bismuth, astringent
Trierra
Tetracycline
Antimiclobial and anti - stress factor
Broad spectrum of activity
Most often introduced on the feed
Milbazon
Tetracycline
Mix: basic tetracycline, neomycin sulfate, tetracyclin sulfate, prednisolone, excipients
Pristinamycin
Various antib (group of sinergistines) Elimin renal In powders, sol, ointments Admin oral or external
Tiamulin (Dynamutilin)
Spectrum: mycoplasma, treponema, leptospira, germs G+ and -
Granules or injection
Toxic if mixed with: mosesin and ionophores
Organic acids
(Topical antifungals)
Mode of action: fungistatic
Commercial: Zicudan (oinment), Mycosid (pulv)
Tolfanate
Topical antifungal
Effect on: Epidermopython, Tricopython, Microsporum
No effect on candida
example: Benzuldazic: tto of dermatophyte
Imidazoles (Topical)
Topical antifungals
Spectrum: antifungal, antiprotozoan, antibact, antiparasitic
Mode of action
1. Block ergosterol synthesis -> enzimatic inhibition
2. Dteremine (through the inhibition): amplifies the ampunt of peroxide in the cells
Most popular: Clotrimazole, Econazole, Miconazole, Ketoconazole, Thiabendazole
Clotrimazole
Imidazol (topical antifungal)
Mode of action: similar imidazol
Spectrum: Aspergillus, Epidermopython, Microsporum, C. albicans
Side effects: rarely produces-> irritation, itching, erithema and edema
Commercial: Canesten
Miconazole
Imidazol (Topical Antiungals)
Mode of action: similar to ketoconazol
In associated preparation: Canoderm, Surolan, OE therapy
Natamycin
Imidazol (Topical Antifungal)
Has cell mb as site of action
Candicidin
Imidazol (Topical Antifungal)
Mode of action: Fungistatic
In ovules, or ointemts
Saramicedin
Imidazol (Topical Antifungal)
Fungistatic
In subcut fung infections
Tricomin
Imidazol (Topical Antifungal)
Fungistatic: Hard to be absorbed
active in tto of candidiasis and trichomoniasis
Variorin
Imidazol (Topical Antifungal)
Fungistatic and fungicidal in trichipythosis
Griseofulvin
Antifungal antibiotic (systemic antifungal)
No effect on candida,
effect on: trichophytosis, epidermophytosis
Teratogen in advanced pregnancies
Stamycin (Nystatin)
Antifungal antibiotic (systemic antifungal)
Polyene macrolide
Mode of action: antifugal -> it occupies the places of stearolic coupling on the fungal cell mb permeability and ion depletion
Spectrum of action: Candida and trichophyton
Not recommended the parenteral admn-> toxic
Commercial: Nysatin tablets
Imidazoles (systemical)
Systemic antifungals
Mode of action: Interferes with ergosterol synthesis and coupling of phospholipids in the fungal cell mb-> rupturing and loss of cell content
Spectrum: candidiasis, criptococcidiosis, aspergillosis, coccidiomycosis
Eliminated through bile
Ketoconazole (metab in liver)
Triazoles
Systemic antifungals
Mode of action : excellent antifungal actv (coupled to aromatic rings)
Spectrum: Aspergillus, Candida, Cryptococcus, coccidioides, histoplasma
Low toxicity
Most known:
- Itraconazole: couples highly to plasma protein
- Fluconazole: penetrates weakly to plasma protein
- Mycetin: in dermatomycosis (fungicidal)
Antiviral antibiotics (other antibiotcs)
Block the protein synthesis and degrades DNA
Intervenes in:
- RNA synthesis
- Stimulates the elaboration of interferon by aproppiate cells
HELENIN-> antiviral activity produced by penicilium
CYTIN-> from cultures of fungis that parasite tea leaves, results in sarcomatosis
PUROMYCIL
Antiprotozoals (other antb)
Interferes with enzymes which ensures purine metab
Inhibits: nuleic acid synthesis
Allicin
Phytonicide (other antib)
Action: germicide
From garlic and onion
Action: G+ and - germs, viruses and acidoresistents
Tomatine
Phytonicide (other antib)
From tomato
Action: germicide
Soectrum: inhibits G+ bact and fungi
Dicumarine
Phytonicide (other antib) Action: germicide From red clover and melilot Spectrum: G+ germs insolv water, solub in organic solv
Lysozime
Zoonicide (other antib)
Action: germicide
In most animal tissues
spermine
Zoonicide (other antib)
Action: germicide
Spectrum: G+
Ecmoline
Zoonicide (other antib)
Action: germicide
From fish roe
G+ and G-
