Analgesics Sandy Kulkarni Analgesics Analgesics are common pain

Analgesics Sandy Kulkarni

Analgesics �Analgesics are common pain relievers. �Many analgesics also have antipyretic properties as well. They can be used to reduce fever �Some analgesics are also antiinflammatory drugs as well

Classification of Analgesics Mild Analgesics Aspirin Ibuprofen Acetaminophen Strong Analgesics Opium Heroin Codeine

Mild Analgesics �Mild Analgesics include over-the-counter pain relievers and fever depressants. �Examples of mild analgesics include Aspirin, acetaminophen, and ibuprofen

Aspirin �Aspirin is a derivative of salicyclic acid �Salicyclic acid was found in the bark of the willow tree and was used as a pain reliever and as a way to relieve fever symptoms of malaria Salicyclic Acid Aspirin

Aspirin �In 1899, Felix Hoffman, a chemist from the Bayer Company, developed a low-cost process to synthesize an ethanoate ester of salicyclic acid, called aspirin �In the synthesis of Aspirin, the ethanoic acid forms an ester with the alcohol group on the second carbon

Aspirin �Aspirin is believed to inhibit the enzyme, Prostaglandin synthase which is formed at the site of an injury. �This inhibits the production of prostaglandins which produce fever and swelling as well as transmitting pain signals to the brain.

Aspirin �Aspirin is able to reduce pain and fevers and dilate blood vessels �Aspirin enlarges blood vessels which helps prevent blood clots. �This vasodilation of the surface blood vessels also allows an increase of heat released which lowers the temperature of a fever �Aspirin is also taken to prevent recurring heart attacks �It may also be effective in preventing prostrate cancer

Side Effects of Aspirin �Aspirin can irritate the stomach lining which may lead to ulcers �If aspirin is used over long periods of time, it may lead to problems with blood clotting �An overdose on aspirin, such as the case with some arthritis sufferers, may lead to dizziness, ringing in the ears, gastrointestinal problems, mental confusion, and bleeding. �Some people are allergic to aspirin leading to bronchial asthma �In children under 12 Aspirin has been linked to Reye’s syndrome

Other Mild Analgesics �Acetaminophen (Paracetamol) �Commonly sold as Tylenol �Ibuprofen �Commonly sold under the name Advil

Acetaminophen �Acetaminophen is a pain reducer, such as Tylenol but does not reduce inflammation �When taken at recommended doses, it has negligible side effects �It’s low level side effects make it favorable to arthritis patients and children �Overuse and overdoses can lead to acute liver failure and kidney damage

Ibuprofen �Ibuprofen is a more powerful pain reliever than aspirin in high doses, but is inferior for anti-inflammation �Side effects include gastrointestinal bleeding and irritation �Can aggravate kidney problems

Strong Analgesics �Only Available by prescription �Used to relieve severe pain associated with injuries, heart attacks, or chronic diseases such as cancer �Most strong analgesics are derived from the opium poppy or synthetically produced �Basically three types: Natural, semi-synthetic, and synthetic

Morphine �Naturally occurring in the poppy- Only needs to be isolated �Very strong pain reliever but also very addictive (2 nd to Heroin) �Usually injected but can be smoked, sniffed or swallowed �Commonly used in hospitals �Large illegal street culture

Codeine �Most commonly used strong analgesic �Similar to Morphine except for the replacement of a (OH-) group for (OCH 3) group �Commonly used with Tylenol as a more mild analgesic � 1/6 as strong as Morphine and less addictive

Heroin �Originally sold as cough suppressant and pain killer 10 times stronger than Morphine �Incredibly addictive (many times, other strong analgesics are needed for withdrawal)

Heroin �Many other problems are �Synthesized from associated with heroin morphine in a addiction including as esterification reaction prostitution and AIDS. with acetyl chloride �It is absorbed by the brain very quickly resulting in a potent high

Other Synthetic Strong Analgesics Vicodin �Is solution of acetaminophen and hydrocodone (the latter being the stronger) �Hydrocodone is addictive and can cause highs. �Usually taken orally �Stronger than codeine but not as strong than Morphine

Synthetic Strong Analgesics (Opioids) �The active area of morphine has been identified and can be synthesized. �This has produced many synthetic analgesics and has allowed scientists to eliminate some of the harmful side effects of more natural analgesics.

Demerol �Demerol (Meperidine) �Used for moderate to severe pain and to stop muscle spasms. �Usually injected or taken orally.

Methadone �Compared to most strong analgesics it is weaker. �Has been synthesized to not have euphoric properties and mild withdrawal effects but is still addictive. �Used as an analgesic but most commonly to help in the withdrawal for Heroin addicts.

Mechanism of Strong Analgesics �The human body contains “natural opiates” in the brain called endorphins �These are produced in the body during extreme conditions such as “running high” and extreme injuries. �When these are absorbed by receptors in the brain the body feels analgesia and the pain is reduced.

Mechanism of Strong Analgesics cont. �Opiates derived from the poppy act in the same way as endorphins but are not natural to the human body. �The “high” is produced because of the absorption of opiates is quicker than endorphins �Drugs such as naloxone act to fill the receptors in the brain but are not analgesics and thus are used to prevent overdoses on analgesics. �Endorphins are not used as analgesics because the cannot be stored and are unstable.

Side Effects of Strong Analgesics Short term �Dulling of Pain �Euphoria �Slow Nervous system �Slowed heart rate �Loss of cough reflex �Nausea �Overdoses can lead to death �Possibility of stroke �Overall slowdown of biological systems Long Term �Addiction and very strong withdrawal effects �Constipation �Loss of libido �Disruptions in menstruation �“Cross-tolerance” �Loss of appetite �Problems associated with buying street drugs i. e. sharing needles AIDS and prostitution.

Local Anesthetics -- Cocaine �Cocaine used in 1885 as a local anesthetic. �Extracted from the plant Erythoxylum coco ([1 R-(exo, exo)]-3 -(Benzoyloxy)-8 -methyl-8 azabicyclo[3. 2. 1]octane-2 -carboxylic acid methyl ester

History of Cocaine �Coca leaves have been chewed by South American Indians for thousands of years. There were used to induce feelings of euphoria �Was banned by Spanish settlers in the 1500 s but the ban was repealed when it became apparent that slaves worked harder while on it �United States cocaine was used in soft drinks until it was classified as narcotic in 1914 �Clinically used as a local anaesthetic for eye operations and in modified synthetic forms for dental treatment (novocaine) and sore throats (benzocaine)

Cocaine �The leaves of the coca plant contain 0. 6% - 1. 8% alkaloidal cocaine �To extract, cocaine leaves are soaked in kerosene and sulfuric acid �HCl is added creating cocaine hydrochloride, which can be extracted as powdery flakes or rocks

Clinical Action �Acts as a reuptake blocker for the monoamines dopamine, norepinephrine and serotonin �interacts with serotonin and muscarinic acetylcholine receptors and the sodium channels �influence on the axonal voltage-gated sodium channels that provides cocaine's local anaesthetic properties

Effects of Cocaine Subjective Physiological �Euphoria �Increased sociability �Increased energy �Hyper vigilance �Increased heart rate �Increased respiration rate �Increased body temperature �Increased blood pressure �Pupil dilation

Derivatives of Cocaine � Cocaine is too addictive and in appropriate for medicinal use � Two derivatives of cocaine are widely used as local anesthetics Procaine or Novacaine � Lidocaine �

Procaine (Novacaine) Novacaine �Principal use in dentistry for temporary numbing of mouth area �First synthesized in 1905 and was the first injectable man-made local anesthetic �Restricts blood vessels, reducing bleeding

Lidocaine �Sodium channel blocker �Administered parenterally for ventricular arrhythmias, subcutaneously for minor surgical procedures, and topically to mucosal surfaces prior to invasive procedures