Antivirals

=** Antivirals **=

What are Viruses??

 * Microscopic organisms that are made up of either DNA or RNA.
 * They have a protective outer layer of protein.
 * They infect cells in our body in order to reproduce.
 * Once they infect the cell, the cell continues to reproduce, but it reproduces the virus instead.
 * Therefore, viruses can also be classified as a "parasite".
 * Can be passed on either by person to person, or hereditary.
 * Because they latch on to the cells, it is very difficult to fight viruses without harming the host's cells.

What are antivirals??

 * Drugs that are used to treat or to prevent the __**viruses**__ **(Not bacterias)** to grow or spread.
 * __**Virals infections** are harder to treat than bacterial infections__. This is because viruses live in our cells, which makes it harder for our immune system to detect and attack them.
 * Therefore antiviral drugs are constantly developed to protect our body from virals.
 * Antivirals do not  destroy their target pathogen, but inhibit their development <span style="font-family: Verdana,Geneva,sans-serif;">.
 * <span style="font-family: Verdana,Geneva,sans-serif;">There are variety of drugs and specific antivirals that are used for specific viruses.
 * <span style="font-family: Verdana,Geneva,sans-serif;">Most of the antiviral drugs that are available nowadays are designed to help the following infections:
 * **HIV, Herpes Viruses** (causes sores, genital herpes, chicken pox, etc.), **Hepatitis B and C** (causes liver cancer) and **influenza A and B viruses**
 * <span style="font-family: Verdana,Geneva,sans-serif;">An example of an antiviral drug is Acyclovir, which is a drug that targets herpes viruses.
 * <span style="font-family: Verdana,Geneva,sans-serif;">It is difficult to design a safe and effective antiviral drug due to viruses that use the host's cell to replicate themselves. (limitation)
 * <span style="font-family: Verdana,Geneva,sans-serif;">Therefore, this is hard to find a target for a drug that does not interfere with the virus and at the same time does not harm the host organism's cells.

<span style="font-family: Verdana,Geneva,sans-serif;">* **__Difference Between Viruses and Bacterias__** * (additional information & is needed for Chem Paper 3 for HL students)

a coat of protein || have DNA and RNA floating freely in cytoplasm and have cell membrane and cell wall || cell to make copies of the viral DNA or RNA. It destroys host cell and releases new viruses || Binary Fission ||
 * ||= **Viruses** ||= **Bacterias** ||
 * **Drugs Used to Cure** ||= Antiviral Drugs ||= Antibacterials ||
 * **Structure** || have DNA or RNA enclosed inside
 * **Reproduction** || Invades host cell and takes over the
 * **Can cause disease?** || YES || YES ||
 * **Infection** || Systemic || Localized ||

This is a diagram that shows different types of viruses (influenza) in different regions of America <span style="font-family: Verdana,Geneva,sans-serif;">


 * __ Common Antiviral Drugs __**
 * <span style="color: #ff0000; font-family: Verdana,Geneva,sans-serif;">Aciclovir
 * <span style="color: #f4a052; font-family: Verdana,Geneva,sans-serif;">Adefovir
 * <span style="color: #eeee49; font-family: Verdana,Geneva,sans-serif;">Famciclovir
 * <span style="color: #00ff00; font-family: Verdana,Geneva,sans-serif;">Ganciclovir
 * <span style="color: #008000; font-family: Verdana,Geneva,sans-serif;">Interferon alfa
 * <span style="color: #0c00ff; font-family: Verdana,Geneva,sans-serif;">Lamivudine
 * <span style="color: #c908e7; font-family: Verdana,Geneva,sans-serif;">Oseltamivir
 * <span style="color: #ff00ff; font-family: Verdana,Geneva,sans-serif;">Ribavirin
 * <span style="color: #f1acf1; font-family: Verdana,Geneva,sans-serif;">Valaciclovir
 * <span style="color: #c0c0c0; font-family: Verdana,Geneva,sans-serif;">Zanamivir

<span style="color: #b21010; font-family: Impact,Charcoal,sans-serif; font-size: 110%;">How do they work?? <span style="color: #b21010; font-family: Impact,Charcoal,sans-serif; font-size: 110%;">- <span style="color: #000000; font-family: Verdana,Geneva,sans-serif; font-size: 110%;">simplified way of how viruses enter and antiviral drugs work <span style="font-family: Verdana,Geneva,sans-serif;">1) Viruses invade body cells <span style="font-family: Verdana,Geneva,sans-serif;">2) They use human genetic material (DNA) to reproduce <span style="font-family: Verdana,Geneva,sans-serif;">3) Antiviral drugs are used to block this process <span style="font-family: Verdana,Geneva,sans-serif;">4) Antivirals can change within body cells to prevent from replicating or entering <span style="font-family: Verdana,Geneva,sans-serif;">5) When the treatment starts, it relieves symptoms within a few days <span style="font-family: Verdana,Geneva,sans-serif;"> (Amantadine blocks viral internalization and uncoating. Neuraminidase inhibitors prevent the neuraminadase from releasing budding viruses and dispersing virions)

<span style="font-family: Verdana,Geneva,sans-serif;">Antidrugs may work by altering the cell's genetic material so that the virus cannot use it to multiply. <span style="font-family: Verdana,Geneva,sans-serif;">Alternatively, they can prevent the viruses from multiplying by blocing enzyme activity within the hosts cell. <span style="color: #0c00ff; font-family: Verdana,Geneva,sans-serif;">__**Different Ways Antivirals WORK!**__ ** (Need to know this for IB CHEM paper 3 for HL students! - vacation assignment!! **<span style="color: #0c00ff; font-family: Verdana,Geneva,sans-serif;">)
 * <span style="color: #0c00ff; font-family: Verdana,Geneva,sans-serif;">Antivirals prevent the virals/viruses from increasing/multiplying by blocking enzyme activity within in the host cell
 * <span style="color: #0c00ff; font-family: Verdana,Geneva,sans-serif;">They also change the binding site of the virus in order for the viruses to NOT bind to cell wall
 * <span style="color: #0c00ff; font-family: Verdana,Geneva,sans-serif;">It has the function to permit the viruses from entering or leaving the cell
 * <span style="color: #0c00ff; font-family: Verdana,Geneva,sans-serif;">Lastly, it changes the host cell's genetic information so that virals cannot use it to multiply

<span style="color: #b21010; font-family: Impact,Charcoal,sans-serif; font-size: 110%;">How are they used?? <span style="font-family: Verdana,Geneva,sans-serif;">
 * <span style="font-family: Verdana,Geneva,sans-serif;">Antivirals can be administrated in __different ways__
 * <span style="font-family: Verdana,Geneva,sans-serif;">Most of the times, it is administrated **orally** in form of __pills, tablets, liquid form__ or even as an __inhaled medication__
 * <span style="font-family: Verdana,Geneva,sans-serif;">Often times, patients receive antiviral drugs __through an IV line__, which enables the medication to enter the bloodstream more rapidly
 * <span style="font-family: Verdana,Geneva,sans-serif;">However, it also depends on the severity and the site of the infection
 * <span style="font-family: Verdana,Geneva,sans-serif;">For instance, herpes infections can be treated by a drug named aciclovir that can be taken by orally or as a topical preparation
 * <span style="font-family: Verdana,Geneva,sans-serif;">If the infection is fairly mild, topical antivirals can be easily bought from a farmacy
 * <span style="font-family: Verdana,Geneva,sans-serif;">However, in the case of drugs like Ganciclovir, they are given via __injection__ from a hospital
 * <span style="font-family: Verdana,Geneva,sans-serif;">More examples:
 * <span style="font-family: Verdana,Geneva,sans-serif;">Ribavirin can be given by **inhaler** to babies with bronchiolitis
 * <span style="font-family: Verdana,Geneva,sans-serif;">By **injection** for Lassa fever
 * <span style="font-family: Verdana,Geneva,sans-serif;">**Orally** for hepatitis C and Oseltamivir
 * <span style="font-family: Verdana,Geneva,sans-serif;">By **inhaler** for influenza and zanamivir

<span style="color: #932525; font-family: Impact,Charcoal,sans-serif;">Side-Effects

 * <span style="font-family: Verdana,Geneva,sans-serif;">Some viruses are resistent to antivirals
 * <span style="font-family: Verdana,Geneva,sans-serif;">Not all antivirals are all-cure medications but can help with fatal illnesses or increase the life expectancy
 * <span style="font-family: Verdana,Geneva,sans-serif;">Most __ common side-effects__<span style="font-family: Verdana,Geneva,sans-serif;"> are:
 * **<span style="font-family: Verdana,Geneva,sans-serif;">gastrointestinal problems **
 * <span style="font-family: Verdana,Geneva,sans-serif;">**sinus** (space within the body) **problems**
 * **<span style="font-family: Verdana,Geneva,sans-serif;">headache **
 * <span style="font-family: Verdana,Geneva,sans-serif;">There are side-effects for different antiviral drugs
 * <span style="font-family: Verdana,Geneva,sans-serif;">When antiviral drugs (like <span style="color: #aa00ff; font-family: Verdana,Geneva,sans-serif;">aciclovir, calaciclovir and famciclovir <span style="font-family: Verdana,Geneva,sans-serif;"><span style="font-family: Verdana,Geneva,sans-serif;">) are taken orally, it is possible to cause **nausea**
 * <span style="font-family: Verdana,Geneva,sans-serif;">When antiviral drug (like <span style="color: #8b07ca; font-family: Verdana,Geneva,sans-serif;">aciclovir <span style="font-family: Verdana,Geneva,sans-serif;">) is taken by injection, it can cause **kidney damage** or **seizures**
 * <span style="color: #9f14db; font-family: Verdana,Geneva,sans-serif;">Ganciclovir <span style="font-family: Verdana,Geneva,sans-serif;"> can cause **skin rashes**, **nausea** and **reduction in red and white blood cell production**
 * <span style="color: #ab11e4; font-family: Verdana,Geneva,sans-serif;">Oseltamivir <span style="font-family: Verdana,Geneva,sans-serif;"> can cause **nausea**, **vomiting**, **intestinal disturbances**, **headache** and **insomnia**
 * <span style="color: #c908e7; font-family: Verdana,Geneva,sans-serif;">Zanamivir <span style="font-family: Verdana,Geneva,sans-serif;"> may cause **breathlessness** (*Therefore, those who have asthma or respiratory problems have to be cautious when taking this antiviral drug*)
 * <span style="color: #ab11e4; font-family: Verdana,Geneva,sans-serif;">Ribavirin <span style="font-family: Verdana,Geneva,sans-serif;"> can cause **anaemia** (disorder in which there is haemoglobin defficiency).


 * <span style="color: #0c00ff; font-family: Verdana,Geneva,sans-serif;">__**Side-effects of treament of AIDS**__ <span style="color: #ff0000; font-family: verdana,geneva,sans-serif;">(*HL students need to know this for the CHEM paper 3!!*)
 * <span style="color: #0c00ff; font-family: Verdana,Geneva,sans-serif;">It is hard to treat AIDS with antiviral drugs because:
 * <span style="color: #0c00ff; font-family: Verdana,Geneva,sans-serif;">HIV uses host cell - this is not good because it the antiviral can damage the host cell when HIV is targeted.
 * <span style="color: #0c00ff; font-family: Verdana,Geneva,sans-serif;">HIV viruses mutate rapidly
 * <span style="color: #0c00ff; font-family: Verdana,Geneva,sans-serif;">Specific proteins on the HIV virus bind to a receptor protein on certain white blood cells
 * <span style="color: #0c00ff; font-family: Verdana,Geneva,sans-serif;">The metabolism is linked closely with that of the cell

//** * For Further Information, Check Out: __Food and Drug Administration (FDA) website__ * **//

<span style="color: #b21010; font-family: Impact,Charcoal,sans-serif; font-size: 110%;">Positive Aspects
 * <span style="font-family: Verdana,Geneva,sans-serif;">Safe for children and pregnant women
 * <span style="font-family: Verdana,Geneva,sans-serif;">Can benefit for those who have higher risk of getting symptoms
 * <span style="font-family: Verdana,Geneva,sans-serif;">Lesson pain and shorten the time of the symptom for 1 or 2 days
 * <span style="font-family: Verdana,Geneva,sans-serif;">Can prevent serious flu like pneumonia

<span style="color: #b21010; font-family: Impact,Charcoal,sans-serif; font-size: 110%;">Negative Aspects
 * <span style="font-family: Verdana,Geneva,sans-serif;">Does not remove the virus itself, just prohibits it from reproducing.
 * <span style="font-family: Verdana,Geneva,sans-serif;">Due to the nature of viruses, it is better to let "nature run its course" by leaving the immune system of the victim to fight it alone.
 * <span style="font-family: Verdana,Geneva,sans-serif;">Various side-effects, such as stated above.
 * <span style="font-family: Verdana,Geneva,sans-serif;">Viruses mutate against the antivirals.

<span style="color: #b21010; font-family: Impact,Charcoal,sans-serif; font-size: 110%;">Antiviral Resistance


 * <span style="font-family: Verdana,Geneva,sans-serif;">Viruses mutate over time, making the antivirals less effective against them.

<span style="color: #b21010; font-family: Impact,Charcoal,sans-serif;">Video <span style="color: #b21010; font-family: Impact,Charcoal,sans-serif;">media type="youtube" key="uwiPidO7K2s" height="315" width="560"

<span style="color: #cb0606; font-family: Impact,Charcoal,sans-serif; font-size: 120%;">Citations

** Works Cited **


 * Barnhart, Amanda, and C. Wilborn. "What Are Antivirals?" //WiseGeek//. Conjecture, n.d. Web. 20 Dec. 2012. <http://www.wisegeek.com/what-are-antivirals.htm>.


 * Crosta, Peter. "What Is A Virus? What Is A Viral Infection?" //MedicalNewsToday.//Medical News Today, 20 July 2009. Web. 23 Jan. 2013. <http://www.medicalnewstoday.com/articles/158179.php>


 * "Influenza and Antiviral Drugs." //Centers for Disease Control and Prevention//. Centers for Disease Control and Prevention, 06 Mar. 2009. Web. 05 Jan. 2013. <http://www.cdc.gov/features/dsfluview2009/index.html>.


 * Kindersley, Dorling. "Antiviral Drugs." //What Are Antiviral Drugs?// N.p., 30 June 2010. Web. 21 Dec. 2012. <http://health.doctissimo.com/drug-treatments/infections-infestations-drugs/antiviral-drugs.html>.


 * "What Are Antivirals?" //What Are Antivirals?// N.p., 01 Sept. 2003. Web. 21 Dec. 2012. <http://www.antibioticresistance.org.uk/ARFAQs.nsf/2f87bc309e63df2d80256c8c004c707d/05f3fbd444ded42780256caa003aa936?OpenDocument>.


 * <span style="font-family: Verdana,Geneva,sans-serif; font-size: 115%;">Worden, Jenni. "Viruses and Bacteria." Netdoctor. Netdoctor, 11 Apr. 2011. Web. 23 Jan. 2013. <http://www.netdoctor.co.uk/health_advice/facts/virusbacteria.htm>.