medicines and drugs antivirals

Diseases caused by viruses influenza SARS measles smallpox AIDS avain flu polio meningitis

antivirals treat viral infections usually virus specific – not broad not that many antivirals available do not destroy but inhibit development of target virus pills, liquids, inhalers, intravenous harmless to host viral infections: HIV, influenza, herpes, hepatitis

bacteria vs virus bacteriavirus  bacteria are self-reproducing i.e. by cell division  viruses are not self-reproducing as they need a host cell to multiply; viruses insert DNA into host cells  bacteria are able to grow, feed and excrete  viruses lack any metabolic functions so they do not grow, feed or excrete  bacteria contain various cell subunits or organelles such as cytoplasm and cell wall which all perform specific functions  viruses consist only of genetic material and protective coating  bacteria are (many times) larger than viruses  viruses are smaller than bacteria  bacteria have more complex DNA  viruses have simpler DNA  bacteria mutate/multiply slower than viruses  viruses mutate/multiply (much) faster than bacteria

Ways in which antiviral drugs work altering the host cell’s genetic material so that the virus cannot use it to multiply preventing the viruses from multiplying by blocking enzyme activity within the host cell. preventing viruses from entering host cell and binding to cellular receptors targeted by the viruses preventing the release of viruses from the cell

Viral infections are harder to treat because… viruses mutate much more quickly so: o they can adapt to drugs (new flu vaccine every year) or o they can evade human immune system response bacteria are more complex and thus can be targeted in more ways - viruses lack subunits/functions which are normally targeted by antibacterials bacteria can be killed or their actions reduced by simple chemical agents but viruses cannot be killed and must be targeted on genetic level different types of bacteria employ similar metabolic processes and thus can be targeted by common antibacterials whilst each kind of virus usually requires special drugs.

AIDS AIDS is syndrome caused by HIV which invades T4 cells which are a type of white blood cell. Treatment of AIDS is problematic because o HIV viruses can mutate rapidly o HIV viruses have similar metabolism to the metabolism of the host cell so any drug could also damage host cell o antiretroviral drug targets are white blood cells which meant to protect us against other pathogens o HIV lies dormant for a while o socioeconomic: high price of antiretroviral drugs, cost to state, access to drugs, o cultural issues: discrimination, stigma