Anti-biotics and antivirals

• -One type of nucleic acid (DNA or RNA)
• -Protein coat- capsid
• -Enclosed by an envelope composed of lipids, proteins and carbohydrates

infectious agents that require a host cell for their replication

bind to the surface of the cell to gain entry

use cellular metabolic activities for replication

results in destruction/damage to host cell resulting in symptoms

the narrow spectrum of host cells in which a virus can multiply

the specific attachment site on the cells surface

• common cold
• influenza
• smallpox
• polio
• HIV

most serious effect is bone marrow suppression

also effect GIT and kidneys

occurs through mutation and subsequent selection of resistant strains

prevent viral infection through the administration of vaccines

able to enter the cells infected with virus

interfere with viral nucleic acid synthesis and regulation

some agents interfere with the ability of virus to bind cells

A disesase caused by a member of the orthomyxviridae family of RNA virsues

clinical feature, fever cough, myalagia, headache, pharyngitis

Oseltamivir 1st line causes GIT side effects

Zanamivir 2nd line

DNA viruses that cause blister like lesions on the skin, genitals and mucosal surfaces

• HSV
• HSV2- gential infections
• VZV- causes shingles (zoster) and chicken pox (varicella)
• CMV- affects multiple body systems (cytomegalovirus)
• EBV-cancer (epstein-barr virus)
• HV6- causes roseola in children

infections treated with ral antiviral 5-10 days

use, acyclovir, famicilovir, valacyclovir

aciclovir (oral/1v), famciclovir and valaciolvir

• use ganciclovir (IV) 
• more toxic

close monitor of bloods

any substance which inhibits the growth or destroyes another organism, usually in bacterial infections

Bactericidal agents- kill bacteroa rapidly, cell wall sysntheis inhibitors e.g. penicillin

bacteriaostatic agents- prevent bacteria from replicating but does not kill them, protein sysnthesis inhibitor

Inhibition of cell wall synthesis

Interference with cell membrane integrity

inhibition of protein sysnthesis

inhibition of nucleic acid synthesis

inhibition of metabolic pathways

• used to treat established infections
•  and as a prophylaxis

Causative organism

Patient

Narrow vs broad

Ability of the antibioic to pentetra the site of infection 

route of admission

Financial costing

Antimicrobial susceptibility testing 

disk-diffusion methid and kirby-bauer test

A1	B1
Inhibitors of cell wall synthesis	B lactam antibacterials, penicillins
A3	B3
A4	B4
A5	B5
A6	B6
A7	B7

inhibit peptidoglycan cell wall synthesis


consists of cephalosproins and others

contain b-lactam ring which is a chemical structure essential for their antibacterial activity

respiratory heart, meningitis, endocarditis, bronchotos, pneumonia and meningococcal meningitis

An enzyme that is resistant to penicllin

Clavulanic acid


prepartions include combinations with amoxicillin (co-amoxiclav)

protein synthesis in the bacteria

Ototoxicity and nephrotoxicity

can cause sepsis. CNS infection, pneumonia

given IV

e.g. gentamicin  ends in mycin or micin

• 4 ring structures
• broad spectrum antibiotic

interferes with protein synthesis

SE, affect teeth must be 12 years older

acne, STI, chronic bronchitis

SE: GIT( nausea vomiting and diarrhea

ends in cycline

Inhibit RNA dependent protein synthesis

e.g erythromycin

uses; respiratory infections

se: normal GIT, ototoxity and hepatotoxixty (jaundice)


e,g azithromycin 

ends in -omycin, -thromycin

Interfere with bacteria use of para aminobenzoic acid (PABA)  precursor of folic acid is essential in cell division


works against briad spectrum of gram postive and gram negative bacteria

e.g. trimethropim

Effective against gram +ve and gram -ve


Respiratory tract infections, UTI's

SE: GIT

Wide bacterial spectrum

can treat UTI or as a prophylactic to UTI

no pateints with renal failure