D3-Analgesics By Caroline Bexfield and Juan David Posada

D.3.1 Describe and Explain the different ways which analgesics prevent pain.  Pain: Is an unpleasant sensory associated with a potential tissue damage which results from interaction between various impulses arriving at the spinal cord and the brain.  When the tissues are injured they released prostaglandins 1 and leukotrienes 2, which are chemicals that causes the pain receptor to be more sensitive. (Sensitized pain receptor react to even gentle stimuli, causing pain).  1. A group of organic compounds derived from essential fatty acids and causing a range of action including inflammation.  2. One of a group of hormones that cause the symptoms of hay fever. Derived from arachidonic acid, the leukotrienes act by mediating immediate hypersensitivity.

Analgesics. Mild Analgesic Used for relief of mild pain Ex. Acetyl Salicylic Acid (ASA) or also known as Aspirins. Metabolic byproduct of phenacetin (Acetaminophen) sold as Tylenol or Paracetamol. Phenacetin Ibuprofen sold as Advil. Non-steroidal anti- inflammatory drugs (NSAIDS). This mild analgesics are non addictive. Strong Opiates Used for relief of very severe pain include the narcotics morphine, heroin (also called diacetylmorphine or diamorphine) and codeine. These are controlled substances that are addictive.

Anesthetics Local anestheticsGeneral anesthetics Are pain killers in localized areas, includes lidocaine and procaine (used in dentistry. Act on the brain and produce reversible unconsciousness as well as insensitivity to pain.

How does Mild Analgesic Work?  They work by blocking the enzyme-controlled synthesis of prostaglandins. Which prevents many effects of the release of prostaglandin.  The Constricting of the blood vessels.  The increase of the permeability of capillaries.

Strong Analgesic (Opiates)  How do they work?  By temporarily binding to the opiate receptors sites in the brain, preventing the transmission of pain impulses without depressing the Central Nervous System (CNS).  Strong Analgesics simulates what the natural painkillers that the body produces (endorphin and encephalin) which are produce immediately after an injury.

D.3.2 Describe the use of SA as a mild analgesic and compare the advantages and disadvantages of using Aspirin and Paracetamol (acetaminophen). Uses of the derivates of SA(salicylic acid)  As a mild analgesic, is used to relieve minors aches and pains, such as sunburns, headaches and arthritis.  As a anti-pyretic, is used to relieve fever.

Aspirin Aspirin  Advantages  Disadvantages  As an anti- inflammatory (when there is swelling from injuries).  As an anti-platelet agent (in prevention for abnormal blood clotting).  Can cause stomach upset.  Risks of gastrointestinal bleeding.  Allergic reaction.  Is one of the most frequent causes of accidental poisoning in infants.

Acetaminophen (Paracetamol) AA dvantages DD oes not upset the stomach. NN o possibilities of internal bleeding. DD isadvantages II s not an effective anti- inflammatory. MM ay have side effect such as blood disorder or kidney damage (vary rarely). CC an not be taken by patients with kidney or liver diseases. OO ver does may cause severe damage to liver, brain damage, coma or even death. :)

D.3.3 Compare the structures of Morphine, Codeine and Heroin.

Chemical Structures HeroinCodeineMorphine

Strong Analgesics  Advantages  Relief of physical pain  Relief of emotional and Psychological pain  Induce a state of euphoria  Reduced tension, worry and fear.  Reduced coughing reflex.  Disadvantages  Major effect on the CNS, Eye and gastrointestinal tract.  Produces drowsiness, mood changes and mental clouding.  Loss of appetite; malnutrition, constipation.  Risk of dangerous infections (AIDS, Hepatitis) due to shared needles.  Sterility  Occasional Death from overdose.