When travelling to a faraway place, we are likely to pack some medicines in the bag. For the astronauts on board of the International Space Station (ISS), whose bodies are hurtling at the speed of 7.6 km (5 miles) per second, 408 km (254 miles) above the Earth, they require medications that are unique for their trip.
For example, in an environment with close to zero gravity, astronauts are floating almost 24/7, which can lead to space motion sickness. It can cause nausea and vomiting, and that's why astronauts need anti-nausea medications. Also due to low gravity, the human body loses the natural force that is required to maintain bone strength and density. On top of space treadmill running, and taking vitamin D and calcium, astronauts in the ISS are also required to take bisphosphonate, a drug used to treat osteoporosis. In case that an astronaut starts acting erratically and violently, there are also tranquillizers in the medicine kit that allows the team to keep the rogue member out of harm's way.
Source: Seeker via Youtube