Nelfinavir

With the pharmacological substance Nelfinavir is a drug that is counted among the so-called HIV protease inhibitors. It is available on the medical market under the trade name Viracept®. The drug nelfinavir is indicated for the antiretroviral therapy of patients infected with HIV-1. The special protease inhibitors are used as part of a so-called 'highly active antiretroviral therapy', where they are administered together with other antiviral substances.

What is nelfinavir?

Basically, nelfinavir is a protease inhibitor that plays an important role in the drug therapy of infections with HIV (human immunodeficiency virus). The approval of the drug nelfinavir for the European market ended in 2013. Due to the decreasing demand for the drug, its distribution by the manufacturer in this region was stopped for the time being.

The salt of methanesulfonic acid is used for pharmaceutical purposes. It should be noted that the synthesis of certain drugs may produce carcinogenic impurities.

This is especially the case when certain sulfonic acids are converted and the production conditions are not ideal. For this reason, the drug nelfinavir was temporarily withdrawn from the pharmaceutical market in 2007. Because in some preparations with nelfinavir, corresponding impurities were detected. However, it is possible to ensure a relatively safe product through appropriate safety measures during manufacture. It is important to ensure that the specified limit values ​​are not exceeded.

Pharmacological effect

The drug nelfinavir has a characteristic mechanism of action, making it suitable for treating infections with the HI virus. After ingestion, the active substance nelfinavir binds almost completely to the proteins that are in the plasma of the blood.

The drug is broken down via the so-called cytochrome system. This is a system of the liver. If a second HIV protease inhibitor is taken at the same time, it delays the breakdown of the drug nelfinavir in the liver.

As a result, the duration of action of the drug nelfinavir is increased. If the drug is taken together with a meal, this has a positive effect on the absorption of the active ingredient.

Basically, the half-life of the substance nelfinavir is around four hours. All metabolites are then excreted from the body in the stool. It can also be taken together with special nucleoside reverse transcriptase inhibitors.

The active ingredient nelfinavir is linked to the so-called viral HIV protease. This plays an important role in the multiplication of the viruses. The main thing is the affinity that the substance has for the HIV-1 and HIV-2 protease. As a result, the viral enzyme is impaired so that the viruses no longer multiply. This reduces the viral load for the patient's organism. Basically, the way nelfinavir works is similar to that of other types of HIV protease inhibitors.

However, the mechanism by which nelfinavir binds to the corresponding enzyme is unique. This means that there is no cross-resistance to other protease inhibitors. Unlike most other HIV protease inhibitors, the active ingredient nelfinavir is able to reduce HIV-1 and HIV-2 proteases evenly. The viruses only develop slight resistance to the drug. However, this development of resistance can largely be avoided by combining nelfinavir with other antiviral substances.

Another advantage is that the absorption of the active ingredient is considerably improved if nelfinavir is taken with a meal. In this case, the drug binds almost completely to the proteins in the blood plasma. The substance is metabolized in the liver. The drug's plasma half-life averages between three and a half and five hours.

Medical application & use

The drug nelfinavir is used in the majority of cases for the drug treatment of infections with HIV type 1. It is used primarily against the background of a so-called 'highly active antiretroviral therapy'.

The drug is suitable for the therapy of adult patients as well as children older than three years. Basically, it is used for antiviral combination therapy for people infected with HIV.

Risks & side effects

During treatment with the substance nelfinavir, undesirable side effects are seen in some cases. However, these do not occur in all patients. The most common side effects such as digestive disorders occur while taking the drug nelfinavir. This manifests itself, for example, in vomiting or diarrhea. Abdominal pain and nausea are also possible. Some people also experience headaches and skin reactions. Some patients develop hepatitis and feel very tired.

There are various interactions between the drug nelfinavir and other medicinal substances to be considered. These include, for example, the preparations cisapride and astemizole as well as benzodiazepines, antiarrhythmics and ergotoxins. If a patient is taking such drugs, nelfinavir is contraindicated. Because this affects the cytochrome P450 system, which is responsible for breaking down nelfinavir.

It is the patient's responsibility to report any side effects or other complaints to the attending physician in order to find an alternative.