Analgesics"An aspirin a day keeps the doctor away." Although this saying may be true, it is not only aspirin that can cure life's pains, but also several other types of painkillers. There are a wide variety of pain relievers. More commonly known as painkillers. Narcotic analgesics act on the central nervous system and modify the user's perception; they are more often used for severe pain and can cause the user to develop an addiction. Non-narcotic pain relievers, called over-the-counter or OTC, work at the site of pain. These do not create tolerance or dependence and do not vary the user's perception. Over-the-counter products are more commonly used daily to treat mild pain. Many people want to treat familiar pains, such as toothaches or headaches, on their own. To treat these types of symptoms, OTCs are used. There are three main types of over-the-counter medications. They are: ·Aspirin (salicylic acid acetate) is an anti-inflammatory (decreases swelling and inflammation), an antipyretic (reduces fever), and an antiplatelet (decreases platelets in the body to thin the blood). Many heart patients take aspirin daily to prevent blood clotting. However, if aspirin is taken in large quantities over long periods of time, it can cause stomach ulcers or other internal damage. The molecular formula for aspirin is C9H8O4. Some examples of aspirin are Bayer, Ecotrin and Aspergum. · Ibuprofen (propionic acid) is an anti-inflammatory and antipyretic. It is often used to treat arthritis, dental pain, menstrual pain, headaches, migraines and back pain. Ibuprofen works by reducing the levels of prostaglandis (substances that cause pain) in the body. This medicine is gentler on the stomach than aspirin. The molecular formula of ibuprofen is C13H18O2. Some examples of ibuprofen are Motrin, Advil and Nuprin. · Acetaminophen (paracetamol) is an alternative to aspirin. It is also an anti-inflammatory, antipyretic and antiplatelet. Acetaminophen is much less likely to cause intestinal side effects than aspirin, but an overdose of this medication can cause severe liver poisoning. The molecular formula for acetaminophen is C8H9NO2. Some examples of acetaminophen are Tylenol, Midol, and Panadol. Each of these over-the-counter pain relievers has different side effects and purposes, but they all share three common elements. These elements are carbon (atomic number 6, atomic mass 12.011), hydrogen (atomic number 1, atomic mass 1.0079), and oxygen (atomic number 8, atomic mass 15.999). Looking at the molecular formulas of each type of over-the-counter pain reliever, these three common elements form the basis of each chemical compound..