medicines and drugs

1. medicines and drugs antivirals

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

3. 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

4. bacteria vs virus

5. 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

6. Viral infections are harder to treat because… • viruses mutate much more quickly so: • they can adapt to drugs (new flu vaccine every year) or • 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.

7. 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 • HIV viruses can mutate rapidly • HIV viruses have similar metabolism to the metabolism of the host cell so any drug could also damage host cell • antiretroviral drug targets are white blood cells which meant to protect us against other pathogens • HIV lies dormant for a while • socioeconomic: high price of antiretroviral drugs, cost to state, access to drugs, • cultural issues: discrimination, stigma