Antiviral drugs are a branch of the bigger anti microbe family that also includes anti bacterial, anti fungal and other types of drugs. The antiviral drugs are different from antibacterial drugs because the antiviral are looking to stop the propagation of the virus reproduction cycle and therefore lead to seizing its multiplication and minimization of its effect on the body. The situation is different with antibacterial drugs as the bacteria could be killed directly using the antibacterial drugs.
The antiviral drugs differ according to which stage of the virus it attacks so, let us take a quick look about the virus lifecycle to know how the antiviral drugs can attack it. The virus consists of the genetic code of the virus covered with a layer of protein; some viruses have another layer of lipid.
The first stage of the virus life cycle is the attachment of the virus to the host cell receptors. At this stage, the antiviral drugs try to compete with the virus to attach to the cell receptors. There are also some antiviral drugs that attach to the receptors of the virus to stop it from searching for the cell receptors. The prominent example for this type of antiviral drugs is the HIV drugs; the researches successful reached a drug that can prevent the virus from binding to one of the two cell receptors.
The second stage is the uncoating phase. This case starts after the entering of the host cell; the virus begins to lose its protein coat to prepare itself for multiplication. Some of the antiviral drugs that combat flue and common cold act on viruses at this stage; it stops the uncoating process only because the virus cannot multiply without exposing its genetic code.
The other types of antiviral drugs target the stages of genetic code replication; some of them target the replication or what so called the transcriptase drugs. Others stop the reconnection of the two strands of DNA and other processes of DNA and RNA replication.
Antiviral drugs are relatively new drugs, they are still developing and scientists are looking for a method to make these antiviral drugs more effective. The trials are carried out now to make the antiviral drug more effective on the virus and less harmful on the host cell itself. The early trials discovered that the old potent antiviral drugs that were discovered in the 80s of the last century had harmful effect on the virus and the host cell as well.