Medicines are used to treat a wide variety of ailments, and there are many different types that start with the letter M. For example, morphine is an opioid medication used to relieve pain. It is derived from the opium poppy plant and was first isolated in 1804 by German pharmacist Friedrich Sertürner. Another type of medicine is methadone, which is also used to treat pain. It was synthesized in 1937 by German chemist Otto Eisleb and is often used as a substitution for heroin in detoxification programs. Other examples of medicines that start with M include meperidine, methocarbamol, and methotrexate. While each of these medicines has a different use, they all play an important role in treating various medical conditions.