Analgesics

In order to better understand this sub topic I have taken the questions that the IB guide says we should be able to answer.
 * Analgesics **

· Describe and explain the different ways that analgesics prevent pain. Mild analgesics function by intercepting the pain stimulus at the source, often by interfering with the production of substances (eg. __prostaglandins__) that cause pain, swelling or fever. Strong analgesics work by temporarily bonding to receptor sites in the brain, preventing the transmission of pain impulses without depressing the central nervous system. In other words, most analgesics work peripherally on the brain and do not affect the central system. This also means that, while analgesics are capable of preventing pain, they do not act on what is causing such pain. Aspirin has been found to be useful in preventing the recurrence of heart attacks. The disadvantages of aspirin include ulceration and stomach bleeding, allergic reactions and Reye's syndrome in children (a potentially fatal liver and brain disorder). Paracetamol is very safe in the correct dose but can, rarely, cause blood disorders and kidney damage. Overdosage can lead to serious liver damage, brain damage and even death.
 * Describe the use of derivatives of salicyclic acid (aspirin) as mild analgesics and compare the advantages and disadvantages of using aspirin and paracetamol (acetaminophen).
 * Paracetamol **
 *  **__Functional Groups __** ||
 *  Acetyl  ||
 *  Benzene Ring  ||
 *  Hydroxyl  ||
 *  Amine  ||

· Compare the structures of morphine, codeine and the semi-synthetic opiate, heroin. Stress the simple modification to the structures of morphine which results in the semi-synthetic drug, heroin.
 * Acetylsalicylic acid **
 *  **__Functional Groups __** ||
 *  Carboxyl  ||
 *  Benzene Ring  ||
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An opioid is any substance that is derived from the opium poppy. Both morphine and codeine alike are extracted directly from the plant, and in some cases a process called morphine methyllation will yield codeine as a product. On the other hand, heroin (diaceylmorphine) is completely derived from morphine.

** __ Structure of Morphine __ ** ** __ Structure of Codeine __ ** ** __ Structure of Diacetylmorphine (Heroin) __ ** · Discuss the advantages and disadvantages of using morphine and its derivatives as strong analgesics. Include the social as well as physiological effects of both short- and long- term use.

Opiates, unlike other analgesics, act directly on the Central Nervous System, which means, it is easier for them to relieve severe or agonizing pain. However for that same reason, opiates and other derivations of morphine can easily cause addiction and physiological dependence. Over a short term use, the consequences of these drugs are: depression, constipation, nausea, vomiting, miosis and several other non lethal adverse effects. However after long term use, not only can these drugs cause physiological dependence, over a long term use there is the risk of respiratory depression caused by an overdose of the drug. The reason why these opioids might be abused is because of the extreme rush and feeling of euphoria it causes while it metabolizes in the body, before it ultimately causes a feeling of rest and easiness. The increase in tolerance of this drug causes the user to increase the dosage until it ultimately causes an overdose. In the long term any pro that the drug might have is ultimately defeated by the risk of physiological dependence and tolerance created by theses drugs. [] [] []