HlV blockade is a virus blockade that is taken after sexual intercourse when HIV infection is suspected. BlockingThe preferred dosing combination is emtricitabine tenofovir tablets, but tenofovir and lamivudine can also be used instead, in combination with raltegravir or in combination with dolutegravir. A course of treatment is given for 28 days.There is no problem with wearing a condom regardless of homosexual heterosexual intercourse.

I specialize in AIDS prevention and I'll answer!

HIV blockade: It refers to the prophylactic use of antiretroviral drugs (ARVs) after HIV exposure (occupational and non-occupational) for the purpose of interrupting the HIV infection of the exposed person, i.e. prophylactic use of drugs for occupational or non-occupational exposure to HIV.

The principle of HIV blockade is actually the use of HIV blocking drugs to block the replication of HIV in the human body.

Antiviral drugs are based on viral replication, including drugs for HIV.HIV replication can be roughly divided into seven steps.

1) HIV virus enters the cell through adsorbed molecules on the surface of the CD4 cell; 2) the process of reverse transcription begins, at which time the reverse transcriptase carried by HIV itself comes into play; 3) the DNA synthesized by reverse transcription is integrated into the host cell's genome; 4) the process of transcription begins to synthesize new mRNA; 5) transcription of the mRNA synthesizes new viral proteins; proteases are required for this; 6) Assembly of new viral particles; 7) Release of newly assembled proteins and particles for maturation.

NNRTIs (Non-Nucleoside Reverse Transcriptase Inhibitors) and NRTIs (Nucleoside Reverse Transcriptase Inhibitors) are the two main classes of typical Reverse Transcriptase Inhibitors that block step 2 in the process of viral replication described above;

PIs (protease inhibitors) are proteases that primarily inhibit the process of protein transcription, which is step 5 in the viral replication process described above;

Integrase inhibitors primarily inhibit the step of fusion and entry of viral particles and CD4 cells, which is step 1 of viral replication as described above;

INSTIs (integrase strand transfer inhibitors) primarily inhibit the integration of virally synthesized cDNA onto the host genome, which is step 3 of viral replication described above;

The mechanism of action of blocking drugs is to block one or more parts of the HIV life cycle, thereby inhibiting viral replication and infection.

What blocking drugs are available and what are the treatment options?

Depending on the grading of the exposure, then the anti-blocking medication to be taken is also different, with no medication required for grade 1 exposures, a duo of medications required for grade 2, and a trio of medications required for grade 3 exposures.

Recommended program: tenofovir + lamivudine + efavirenz. Replace Tenofovir with Zidovudine for renal insufficiency, Efavirenz has many side effects and is contraindicated in pregnant women, it can be replaced with Raltegravir.

How long do I need to take the blocking medication?

Blocking medications are typically taken for 28 days, and studies have shown that shorter than 28 days, the blocking effectiveness of the medication is compromised and can easily lead to blocking failure. The medication cannot be stopped for less than 28 days.

What are the side effects of HIV blocking drugs?

Commonly used blocking drugs, may cause dizziness, nausea, fatigue, anorexia, etc. Occasionally, a viral rash may develop, but the chances are very small. Efavirenz has neurological effects that may cause headaches, excessive dreams, depression, etc. It is contraindicated in pregnant women.

How soon after exposure is the best time to take a blocking drug?

With high-risk behaviors (sexual intercourse, occupational exposure, etc.), the medication is most effective when taken within 1-2 hours, and the blockade remains effective when taken within 72 hours. Beyond 72 hours, HIV blockade success decreases.

As for why 72 hours? Mainly because within this stage, the virus then has not yet spread from the heavy initial infected cells to other cells inside, this time reasonable and timely use of drugs, can prevent the spread of the virus. Of course, at this time the drug will not kill the virus, but the spread of the virus will be effectively controlled, with the passage of time, the initial virus-infected cells will die, and the virus will not spread to new cells, the virus will be removed from the body.

Some exposed individuals have asked if it is okay to take the medication beyond 72 hours. It is possible to take the medication beyond 72 hours because the earlier the medication is taken, although the effect of blocking the treatment is reduced, it has a great benefit for the later effects of the treatment.

The mechanism of action of HIV blocking drugs isBlocking one or more parts of the HIV life cycle, thereby inhibiting viral replication and infection.

What should I do if I am worried about getting infected with HIV or if it is clear that the person I am talking to is living with HIV after high-risk behavior?

Anxiety, frustration, and regret can't solve the real problem, so is there no way out after this kind of high-risk behavior? In fact, it is not, you can use blocking drugs, is not it like the existence of a savior?

Based on the analysis of the study.The probability of failure of HIV blockade is about 0.5% if the blockade drug is taken promptly after high-risk behaviorsThe premise is that it needs to be used in a regulated manner for a certain period of time.

● What factors are associated with the success of that HIV blockade?

1. Time, time, time .I'm going to say this three times.The drug is most effective when taken within one to two hours, and remains effective when used within 72 hours, beyond which how it is blocked is extremely ineffective. Of course, even if it's been more than 72 hours, prompt medication is currently recommended.

2. Correct choice of medication, currently for adults and adolescents aged ≥13 years, the preferred combination of prophylactic medication is emtricitabine tenofovir tablets, which can also be replaced by tenofovir and lamivudine, combined with raltegravir or combined with doxorubicin. A course of treatment is given for 28 days. (Note: Medications must be used under a doctor's supervision）

3. Whether you still engage in high-risk behaviors while taking the medication. It is recommended to avoid sexual intercourse while taking the medication. Avoid high-risk exposure again, high-risk factors are not removed, the drug is not useful.

● So, is there any effect on the body from using these drugs? Or are there any side effects? Well, of course, all medicines are poisonous, and the side effects of this class of medicines are relatively strong, common ones such as dizziness, nausea, and fatigue. Some will have an effect on the nerves, causing headaches, excessive dreams, etc. Each person's response to the drug is different and there are certain differences. Generally speaking, the side effects will be relatively obvious in the pre-dose period.

● How long should the medication be used? The answer is 28 days, shorter than 28 days the effect of blockade is affected, or even lead to the failure of the blockade, more than 28 days relative to the clinical significance is not very large. Medications must be applied in a standardized manner, and if they are not taken at the right time, or if they are added or subtracted at random, they may also have an impact on the effectiveness of the blockade.

So is this medicine expensive?

This drug is still relatively expensive, the specific price of each place there are some differences, it is recommended to consult the local CDC or designated hospitals.

And just to be clear.Blocking medication is only a remedy after high risk and has a certain probability of failure, so it can not be used as a regular preventive medication, have unclean sex, wear a condom, more reliable.