Final answer:
Protease inhibitors are medications that can be used prophylactically to reduce HIV transmission
Step-by-step explanation:
The medication that can be used prophylactically by a client who doesn't have an HIV infection to reduce HIV transmission is a protease inhibitor. These medications are part of highly active antiretroviral therapy (HAART) and work by decreasing the amount of HIV in the body and preventing opportunistic infections that can lead to death.