There are many different medicines that start with the letter W. These include antibiotics, antihistamines, and painkillers. Each of these medicines has a different purpose and can be used to treat a variety of conditions. Antibiotics are used to treat infections caused by bacteria. They work by killing the bacteria or preventing them from reproducing. Antihistamines are used to treat allergies. They work by blocking the action of histamine, a substance that is released during an allergic reaction. Painkillers are used to relieve pain. They work by blocking the transmission of pain signals to the brain. As you can see, there are many different types of medicines that start with the letter W. Each one has a specific purpose and can be used to treat a variety of conditions.