ANTI ALLERGIC DRUGS.pptx

anti histamine drugs

1. Anti-allergic drugs Pharmacology department Azerbaijan medical university ADHIL HASBULLA 119I4A

2. Introduction. Non-steroidal anti-inflammatory drugs  ( NSAID ) are members of a  therapeutic   drug class  which  reduces pain ,  decreases inflammation ,  decreases fever , and  prevents blood clots . Side effects depend on the specific drug, its dose and duration of use, but largely include an increased risk of  gastrointestinal ulcers and bleeds ,  heart attack , and  kidney disease .

3. The term  non-steroidal  distinguishes these drugs from  steroids , which while having a similar  eicosanoid -depressing, anti-inflammatory action, have a broad range of other effects. First used in 1960, the term served to distance these medications from steroids, which were particularly stigmatized at the time due to some connotations with  anabolic steroid  abuse. NSAIDs work by inhibiting the activity of  cyclooxygenase  enzymes ( COX-1  or  COX-2 ). In cells, these enzymes are involved in the synthesis of key biological mediators, namely  prostaglandins , which are involved in  inflammation , and  thromboxanes , which are involved in  blood clotting . Coated 200 mg ibuprofen tablets

4. There are two general types of NSAIDs available: non-selective, and  COX-2 selective . Most NSAIDs are non-selective, and inhibit the activity of both COX-1 and COX-2. These NSAIDs, while reducing inflammation, also inhibit platelet aggregation and increase the risk of  gastrointestinal ulcers  and bleeds. COX-2 selective inhibitors have fewer gastrointestinal side effects, but promote  thrombosis , and some of these agents substantially increase the risk of heart attack. As a result, certain older COX-2 selective inhibitors are no longer used due to the high risk of undiagnosed  vascular disease . These differential effects are due to the different roles and tissue localizations of each COX isoenzyme. By inhibiting physiological COX activity, all NSAIDs increase the risk of kidney disease and through a related mechanism, heart attack. In addition, NSAIDs can blunt the production of  erythropoietin , resulting in anemia, since hemoglobin needs this hormone to be produced.

5. The most prominent NSAIDs are  aspirin ,  ibuprofen , and  naproxen ; all available  over the counter  (OTC) in most countries. Paracetamol  (acetaminophen) is generally not considered an NSAID because it has only minor anti-inflammatory activity. Paracetamol treats pain mainly by blocking COX-2 and inhibiting  endocannabinoid  reuptake almost exclusively within the brain, but not much in the rest of the body.

6. NSAIDs are often suggested for the treatment of acute or chronic conditions where  pain  and inflammation are present. NSAIDs are generally used for the symptomatic relief of the following conditions: Osteoarthritis Rheumatoid arthritis Mild-to-moderate pain due to inflammation and tissue injury Low back pain Inflammatory arthropathies (e.g.,  ankylosing spondylitis ,  psoriatic arthritis ,  reactive arthritis ) Tennis elbow Headache Migraine Acute  gout Dysmenorrhea  ( menstrual  pain) Metastatic  bone pain Postoperative pain Muscle stiffness and pain due to  Parkinson's disease Pyrexia  (fever) Ileus Renal colic Macular edema Traumatic injury

7. Chronic pain and cancer related pain. The effectiveness of NSAIDs for treating non-cancer chronic pain and cancer-related pain in children and adolescents is not clear. There have not been sufficient numbers of high-quality randomized controlled trials conducted.

8. Inflammation. Differences in anti-inflammatory activity between the various individual NSAIDs are small, but there is considerable variation in individual patient response, and tolerance to these drugs. About 60% of patients will respond to any NSAID; of the others, those who do not respond to one may well respond to another. Pain relief starts soon after taking the first dose, and a full analgesic effect should normally be obtained within a week, whereas an anti-inflammatory effect may not be achieved (or may not be clinically assessable) for up to three weeks. If appropriate responses are not obtained within these times, another NSAID should be tried.

9. Surgical pain. Pain following  surgery  can be significant, and many people require strong pain medications such as opioids. There is some low-certainty evidence that starting NSAID painkiller medications in adults early, before surgery, may help reduce post-operative pain, and also reduce the dose or quantity of opioid medications required after surgery. Any increase risk of surgical bleeding, bleeding in the gastrointestinal system, myocardial infarctions, or injury to the kidneys has not been well studied. When used in combination with paracetamol, the analgesic effect on post-operative pain may be improved.

10. Aspirin. Aspirin , the only NSAID able to irreversibly inhibit  COX-1 , is also indicated for  antithrombosis  through  inhibition of platelet aggregation . This is useful for the management of arterial  thrombosis , and prevention of adverse cardiovascular events like heart attacks. Aspirin inhibits platelet aggregation by inhibiting the action of  thromboxane A 2 .

11. Contraindications. NSAIDs may be used with caution by people with the following conditions: Irritable bowel syndrome  (IBS) Persons who are over age 50, and who have a family history of gastrointestinal (GI) problems Persons who have had previous gastrointestinal problems from NSAID use

12. NSAIDs should usually be avoided by people with the following conditions: Peptic ulcer  or stomach bleeding Uncontrolled  hypertension Kidney disease People that suffer with  inflammatory bowel disease  (Crohn's disease or ulcerative colitis) Past  transient ischemic attack  (excluding  aspirin ) Past  stroke  (excluding  aspirin ) Past  myocardial infarction  (excluding  aspirin ) Coronary artery disease  (excluding  aspirin ) Undergoing  coronary artery bypass surgery Congestive heart failure  (excluding low-dose aspirin) In third trimester of pregnancy Persons who have undergone  gastric bypass surgery Persons who have a history of allergic or allergic-type  NSAID hypersensitivity reactions , e.g.  aspirin-induced asthma

13. Mechanism of action.

14. Anti-pyretic action. NSAIDs have  antipyretic  activity and can be used to treat fever. Fever is caused by elevated levels of  prostaglandin E2 , which alters the firing rate of neurons within the  hypothalamus  that control thermoregulation. Antipyretics work by inhibiting the enzyme COX, which causes the general inhibition of  prostanoid  biosynthesis ( PGE2 ) within the  hypothalamus . PGE2 signals to the hypothalamus to increase the body's thermal setpoint.  Ibuprofen  has been shown more effective as an  antipyretic  than  paracetamol  (acetaminophen).  Arachidonic acid  is the precursor substrate for cyclooxygenase leading to the production of prostaglandins F, D, and E.

15. Classification. NSAIDs can be classified based on their chemical structure or mechanism of action. Older NSAIDs were known long before their mechanism of action was elucidated and were for this reason classified by chemical structure or origin. Newer substances are more often classified by mechanism of action. Burana 600 mg –  ibuprofen  package

16. Pharmacokinetics. Most nonsteroidal anti-inflammatory drugs are weak acids, with a pKa of 3–5. They are absorbed well from the  stomach  and intestinal mucosa. They are highly protein-bound in plasma (typically >95%), usually to  albumin , so that their  volume of distribution  typically approximates to plasma volume. Most NSAIDs are metabolized in the  liver  by oxidation and conjugation to inactive metabolites that typically are excreted in the  urine , though some drugs are partially excreted in  bile . Metabolism may be abnormal in certain disease states, and accumulation may occur even with normal dosage. Ibuprofen and diclofenac have short half-lives (2–3 hours). Some NSAIDs (typically oxicams) have very long half-lives (e.g. 20–60 hours).

17. One of the first advertisements for Bayer Aspirin, published in  The New York Times  in 1917

18. Veterinary use. Research supports the use of NSAIDs for the control of pain associated with veterinary procedures such as dehorning and castration of calves. The best effect is obtained by combining a short-term local anesthetic such as  lidocaine  with an NSAID acting as a longer term analgesic. However, as different species have varying reactions to different medications in the NSAID family, little of the existing research data can be extrapolated to animal species other than those specifically studied, and the relevant government agency in one area sometimes prohibits uses approved in other jurisdictions. For example,  ketoprofen 's effects have been studied in horses more than in  ruminants  but, due to controversy over its use in racehorses, veterinarians who treat livestock in the United States more commonly prescribe  flunixin   meglumine , which, while labeled for use in such animals, is not indicated for post-operative pain.