Pharmacy and Medicine

An opioid is a chemical that works by binding to opioid receptors, which are found principally in the central nervous system and the gastrointestinal tract. The receptors in these two organ systems mediate both the beneficial effects, and the undesirable side effects of opioids.
The analgesic (pain relieving) effects of opioids are due to decreased perception of pain, decreased reaction to pain as well as by increased pain tolerance. The side effects of opioids include sedation, respiratory depression, and constipation. Opioids can cause cough suppression, which can be both an indication for opioid administration or an unintended side effect. Physical dependence can develop with ongoing administration of opioids, leading to a withdrawal syndrome with abrupt discontinuation. Opioids can produce a feeling of euphoria, and this effect, coupled with physical dependence, can lead to the abuse of opioids by some individuals. However, abuse of opiods is uncommon in patients prescribed opioids for the treatment of pain.
Although the term opiate is often used as a synonym for opioid, it is more properly limited to the natural opium alkaloids occurring in the resin of the opium poppy and the semi-synthetic opioids derived from them.
Contents
*Classification & Mechanism Of Action:
1.Endogenous opioids
Dunniod-peptides that are produced in the body include:
* Endorphins
* Enkephalins
* Dynorphins
* Endomorphins
ß-endorphin is expressed in Pro-opiomelanocortin (POMC) cells in the arcuate nucleus and in a small population of neurons in the brainstem, and acts through µ-opioid receptors. ß-endorphin has many effects, including on sexual behavior and appetite. ß-endorphin is also secreted into the circulation from pituitary corticotropes and melanotropes. a-neoendorphin is also expressed in POMC cells in the arcuate nucleus.
enkephalin is widely distributed in the CNS; [met]-enkephalin is a product of the proenkephalin gene, and acts through µ and d-opioid receptors. [leu]-enkephalin, also a product of the proenkephalin gene, acts through d-opioid receptors.
Dynorphin acts through ?-opioid receptors, and is widely distributed in the CNS, including in the spinal cord and hypothalamus, including in particular the arcuate nucleus and in both oxytocin and vasopressin neurons in the supraoptic nucleus.
Endomorphin acts through µ-opioid receptors, and is more potent than other endogenous opioids at these receptors.
2.Opium alkaloids
Phenanthrenes naturally occurring in opium:
* Codeine,Morphine,Thebaine
Preparations of mixed opium alkaloids, including papaveretum, are still occasionally used.
3.Semisynthetic derivatives
* Diacetylmorphine (heroin),Dihydrocodeine,Hydrocodone,Nicomorphine,Hydromorphone,
Oxycodone,Oxymorphone
4.Synthetic opioids
a.Anilidopiperidines
* Fentanyl,Alphamethylfentanyl,Alfentanil,Sufentalin,Remifentanil
b.Phenylpiperidines
* Pethidine (meperidine),Ketobemidone,Allylprodine,Prodine,PEPAP
c.Diphenylpropylamine derivatives
* Propoxyphene,Dextopropoxyphene,Bezitramide,Methadone,
* Levomethadyl Acetate (LAAM)
* Loperamide (used for diarrhoea, does not cross the blood-brain barrier)
* Diphenoxylate (used for diarrhoea, does not appreciably cross the blood-brain barrier)
d.Benzomorphan derivatives
* Dezocine,Petazocain,Phenazocain
e.Oripavine derivatives
* Buprenorphine,Dihydrophene,Etrophine
f.Morphinan derivatives
* Butorphanol,Nalbuphine,Levorphanol,Levomethophan
5.Others
* Lefetamine,Meptazinol,Tilidine,Tramadol
6.Opioid antagonists
* Nalmefene,Naloxone,Naltrexone
Adverse Effect:
nausea and vomiting, drowsiness, itching, dry mouth, miosis, and constipation.
dose-related respiratory depression (especially with more potent opioids), confusion, hallucinations, delirium, urticaria, hypothermia, bradycardia/tachycardia, orthostatic hypotension, dizziness, headache, urinary retention, ureteric or biliary spasm, muscle rigidity, myoclonus (with high doses), and flushing (due to histamine release, except fentanyl and remifentanil)

Non-steroidal anti-inflammatory drugs, usually abbreviated to NSAIDs or NAIDs, are drugs with analgesic, antipyretic (lowering an elevated body temperature and relieving pain without impairing consciousness) and, in higher doses, with anti-inflammatory effects (reducing inflammation). The term "non-steroidal" is used to distinguish these drugs from steroids, which (among a broad range of other effects) have a similar eicosanoid-depressing, anti-inflammatory action. As analgesics, NSAIDs are unusual in that they are non-narcotic.The most prominent members of this group of drugs are aspirin, ibuprofen, and naproxen partly because they are available over-the-counter in many areas.
Classification:
1.Salicylates
Aspirin (acetylsalicylic acid) · Aloxiprin · Benorylate · Diflunisal · Ethenzamide · Magnesium salicylate · Methyl salicylate · Salsalate · Salicin · Salicylamide · Sodium salicylate
2.Arylalkanoic acids
Diclofenac · Aceclofenac · Acemetacin · Alclofenac · Bromfenac · Etodolac · Indometacin · Indometacin farnesil · Nabumetone · Oxametacin · Proglumetacin · Sulindac · Tolmetin
3.2-Arylpropionic acids
(profens)
Ibuprofen · Alminoprofen · Benoxaprofen · Carprofen · Dexibuprofen · Dexketoprofen · Fenbufen · Fenoprofen · Flunoxaprofen · Flurbiprofen · Ibuproxam · Indoprofen† · Ketoprofen · Ketorolac · Loxoprofen · Miroprofen · Naproxen · Oxaprozin · Pirprofen · Suprofen · Tarenflurbil · Tiaprofenic acid
4.N-Arylanthranilic acids
(fenamic acids)
Mefenamic acid · Flufenamic acid · Meclofenamic acid · Tolfenamic acid
5.Pyrazolidine derivatives
Phenylbutazone · Ampyrone · Azapropazone · Clofezone · Kebuzone · Metamizole† · Mofebutazone · Oxyphenbutazone · Phenazone · Sulfinpyrazone
6.Oxicams
Piroxicam · Droxicam · Lornoxicam · Meloxicam · Tenoxicam · Ampiroxicam
7.COX-2 inhibitors
Celecoxib · Deracoxib‡ · Etoricoxib · Firocoxib‡ · Lumiracoxib† · Parecoxib · Rofecoxib† · Valdecoxib
8.Sulfonanilides
Nimesulide
9..Topically used products
Bendazac · Diclofenac · Etofenamate · Felbinac · Flurbiprofen · Ibuprofen · Indometacin · Ketoprofen · Naproxen · Piroxicam · Suprofen
10.Others
Fluproquazone
Mechanism Of Action:
Most NSAIDs act as non-selective inhibitors of the enzyme cyclooxygenase, inhibiting both the cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) isoenzymes. Cyclooxygenase catalyzes the formation of prostaglandins and thromboxane from arachidonic acid (itself derived from the cellular phospholipid bilayer by phospholipase A2). Prostaglandins act (among other things) as messenger molecules in the process of inflammation. This mechanism of action was elucidated by John Vane, who later received a Nobel Prize for his work (see Mechanism of action of aspirin). A newly discovered COX-3 may also have some role.
Uses:
NSAIDs are usually indicated for the treatment of acute or chronic conditions where pain and inflammation are present. Research continues into their potential for prevention of colorectal cancer, and treatment of other conditions, such as cancer and cardiovascular disease.
* Rheumatoid arthritis
* Osteoarthritis
* Inflammatory arthropathies (e.g. ankylosing spondylitis, psoriatic arthritis, Reiter's syndrome)
* Acute gout
* Dysmenorrhoea (menstrual pain)
* Metastatic bone pain
* Headache and migraine
* Postoperative pain
* Mild-to-moderate pain due to inflammation and tissue injury
* Pyrexia (fever)
* Ileus
* Renal colic
* They are also given to neonate infants whose ductus arteriosus is not closed within 24 hours of birth
Adverse Effect:
Advedse drug Reaction
Dyspepsia
Inflammatory Bowel Disease like Ulcerative Colitis & Crohn's disease