HIV blocking drugs can prevent patients from contracting HIV after having high-risk behaviors. In fact, HIV blocking drugs are HIV antiviral drugs. If it takes more than 2 hours, you should take the blocking medication within 48 hours, which is also more effective. If possible, the medication should be taken within 72 hours after 48 hours, and there is still hope for successful blockade by taking a complete blocking cycle. After stopping the medication, continuous HIV testing should be performed for more than 6 months to determine if the patient is successfully blocked.