Anti-Influenza Agents and Treatments

Viral proteins on the surface of influenza A viruses, used to classify the virus's subtype based on their structure. They are responsible for attaching to host cells.

Influenza A viruses can infect multiple animals, including birds, pigs, and humans. This allows the virus to spread more easily and create a reservoir of infection.

The ability of a virus to spread efficiently from person to person through respiratory droplets. Influenza A viruses have a higher potential for pandemics due to their ability to circulate among humans.

Neuraminidase inhibitors are antiviral drugs that block the release of new viral particles from infected cells, preventing the spread of infection. They work against both influenza A and B viruses.

Adamantanes are antiviral drugs that interfere with the uncoating process of influenza A viruses, preventing them from entering and infecting new cells. They are effective against influenza A only.

Amantadine and rimantadine are examples of adamantane drugs which have been highly affected by viral resistance, meaning they are less effective at fighting many influenza strains.

Oseltamivir and zanamivir are neuraminidase inhibitors, often prescribed for influenza treatment, particularly in high-risk individuals or for severe infections.

Influenza A and B viruses are classified by their core proteins and surface proteins. This classification helps track viral evolution and develop targeted treatments.

Oseltamivir is a medicine that is used to treat and prevent influenza (flu). It is taken by mouth and works by blocking a protein called neuraminidase that the flu virus needs to spread.

Oseltamivir works best when started within 48 hours of the onset of flu symptoms. This is because the replication of the flu virus peaks at 24-72 hours after symptoms appear.

Oseltamivir is absorbed into the bloodstream and reaches various parts of the body, including the middle ear and sinus fluid. This allows it to target the flu virus in different areas of the body.

The active form of oseltamivir, called oseltamivir carboxylate, lasts in the body for about 6-10 hours. This means that it takes about 6-10 hours for the drug's concentration to decrease by half.

Oseltamivir can be adjusted for people with kidney problems because their bodies might not process the drug as quickly. The dosage might need to be changed based on their kidney function.

Zanamivir is another medicine for flu, but it is inhaled directly into the lungs instead of being taken by mouth. It works by targeting the flu virus in the respiratory tract.

Zanamivir reaches high concentrations in the lungs, making it effective in fighting the flu virus right at the site of infection. It's designed to stay in the lungs for a longer period of time, which is important for fighting the flu.

Only a small amount of zanamivir is actually absorbed into the bloodstream. Most of it stays in the lungs, where it is needed to fight the flu.

Zanamivir is an antiviral medication used to treat influenza. It works by blocking a key protein called neuraminidase, which is essential for the influenza virus to spread within the body.

Zanamivir can cause side effects like coughing, shortness of breath, and nasal and throat discomfort. However, these side effects are usually mild and temporary.

Although zanamivir is generally effective against influenza, viral resistance has been observed. However, the majority of influenza strains remain susceptible to the drug.

Peramivir is another antiviral medication effective against both influenza A and B. It is administered as a single intravenous dose.

Peramivir is primarily eliminated through the kidneys, so dose adjustments might be necessary in individuals with kidney problems.

While peramivir generally has a good safety profile, diarrhea is a common side effect. In rare cases, it could lead to serious skin reactions or alterations in mental state.

Amantadine and rimantadine belong to a class of drugs called adamantanes, which target a specific protein (M2) on influenza A viruses.

Amantadine and rimantadine inhibit the uncoating process of influenza A viruses, preventing them from releasing their genetic material and replicating.

Amantadine and rimantadine are antiviral drugs that can prevent or shorten influenza A infections, but their effectiveness is limited due to frequent viral resistance.

Amantadine and rimantadine work by interfering with the uncoating process of influenza A viruses, blocking them from entering host cells.

Amantadine and rimantadine are excreted differently by the body. Amantadine is excreted unchanged, while rimantadine is metabolized before excretion.

Both amantadine and rimantadine can cause adverse effects like nausea, nervousness, and insomnia. Serious side effects include behavior changes, hallucinations, and seizures.

Dose adjustments are necessary for patients with renal insufficiency, hepatic insufficiency, and older adults when using either amantadine or rimantadine.

Adamantanes are effective for influenza A but not influenza B. They can prevent clinical illness and shorten its duration if used before exposure.

Amantadine and rimantadine are teratogenic and embryotoxic, meaning they can harm a developing fetus. Birth defects have been reported after exposure during pregnancy.

High plasma concentrations of amantadine or rimantadine can increase the risk of serious side effects, especially in patients with renal insufficiency, seizure disorders, or advanced age.