NSAIDs and Drugs used in arthritis 1 Nonsteroidal antiinflammatory drugs (NSAIDs) Nonsteroidal antiinflammatory drugs have good analgesic efficacy (but often less than that of opioids), relatively rapid onset, and adverse effects (eg, possibly fatal gastrointestinal bleeding and disturbed salt and water balance). All NSAID effect-analgesic, anti-inflammatory, antipyretic, and antiplatelet-are thought to be due to decreased prostanoid biosynthesis via COX inhibition. Traditional NSAIDs inhibit both COX-1 and COX-2 isoforms, but newer COX-2 inhibitors are more selective. The analgesic efficacy of selective COX-2 inhibitors (coxibs) is approximately equal to that of traditional NSAIDs, but the adverse effects of COX-2 inhibition have yet to be fully characterized and are somewhat controversial. The ability to selectively inhibit COX-2 has been related to the difference in amino acids at position 523 of COX-1 and COX-2: isoleucine in COX-1, valine in COX-2. The mechanism of action of acetaminophen is uncertain but is thought to be via CNS effects. Corticosteroids ยับยั้ง Phospholipase A 2 ซึ่งทาหน้าที่เปลี่ยนแปลง Membrane lipid (e.g., phosphatidylinositol) ไปเป็น Arachidonic acid ลดการอักเสบ ลด ความไวของหลอดลมต่อสิ่งกระตุ ้น ไม่มีฤทธิ ์ ในการขยายหลอดลม ยาในกลุ ่มนี ้ได ้แก่ beclomethasone dipropionate, triamcinolone acetonide, flunisolide, budesonide dipropionate, fluticasone propionate NSAIDs, acetaminophen, COX-2 inhibitors, aspirin ยับยั้ง Cyclooxygenase (COX-1, COX-2) ซึ่งทาหน้าที่เปลี่ยนแปลง Arachidonic acid ไปเป็น Endoperoxides (PGG 2 , PGH 2 ) Zileuton [5-lipoxygenase inhibitor] ยับยั้ง Lipoxygenase ซึ่งทาหน้าที่เปลี่ยนแปลง Arachidonic acid ไปเป็น Hydroperoxides (HPETEs) Zafirlukast, montelukast ยับยั้งการเปลี่ยนแปลงของ Leukotrienes (LTC 4 ,LTD 4 ,LTE 4 ) ที่ทาให้เกิด Bronchoconstriction ป้ องกันการหอบ Prostacyclin (PGI 2 ) Platelet aggregation, Vasodilation, Uterine tone || Prostaglandins (PGE 2 ) Vascular tone, Pain, Uterine tone, Temperature Thromboxane (TxA 2 ) Platelet aggregation, Vasoconstriction || Leukotrienes มีบทบาทสาคัญในการเกิดการอักเสบ (lipoxygenase inhibitors(LTC 4 ,LTD4 4 ) และ anaphylaxis) Traditional NSAIDs - Salicylates: Aspirin (ก), Diflunisal - Acetic acid: Indomethacin (ก)(Indocid®), Sulindac, Etodolac - Tolmetin, Ketorolac, Diclofenac (ก)(Voltaren®) - Fenamates: Mefenamic acid (Ponstan®), Meclofenamate, Flufenamic acid - Propionic acid: Ibuprofen(ก), Naproxen(ก)(Naprosyn® LE), Fenoprofen, Ketoprofen, Flurbiprofen, Oxaprozin - Enolic acid: Piroxicam (ข)(Feldene®), Meloxicam, Nabumetone COX-2 Selective inhibitors - 1 st Gen: Celecoxib (Celebrex®), Nimesulide (Nidol®) - 2 nd Gen: Parecoxib, Etoricoxib (Arcoxia®), lumiracoxib Para-aminophenol derivative: Acetaminophen (paracetamol) บางตาราจัดเป็น NSAIDs
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NSAIDs and Drugs used in arthritis
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Nonsteroidal antiinflammatory drugs (NSAIDs)
Nonsteroidal antiinflammatory drugs have good analgesic efficacy (but often less than that of opioids), relatively rapid onset, and adverse effects (eg, possibly fatal gastrointestinal bleeding and disturbed salt and water balance). All NSAID effect-analgesic, anti-inflammatory, antipyretic, and antiplatelet-are thought to be due to decreased prostanoid biosynthesis via COX inhibition. Traditional NSAIDs inhibit both COX-1 and COX-2 isoforms, but newer COX-2 inhibitors are more selective. The analgesic efficacy of selective COX-2 inhibitors (coxibs) is approximately equal to that of traditional NSAIDs, but the adverse effects of COX-2 inhibition have yet to be fully characterized and are somewhat controversial. The ability to selectively inhibit COX-2 has been related to the difference in amino acids at position 523 of COX-1 and COX-2: isoleucine in COX-1, valine in COX-2. The mechanism of action of acetaminophen is uncertain but is thought to be via CNS effects.
Antipyretic, analgesic, but lacking anti-inflammatory properties. Used instead of aspirin to prevent Reye’s syndrome in children with viral infection. ใชลดไขในเดกและผใหญ เพราะไมมผลเสยตอทางเดนอาหาร และไมพบการเกด Reye’s syndrome
Overdose produces hepatic necrosis; acetaminophen metabolite depletes glutathione and forms toxic tissue adducts in liver. N-acetylcysteine is antidote – regenerates glutathione. พษตอตบ ท าใหตบวายซงเสยชวตเมอไดรบเกนขนาด แกพษดวย N-acetylcysteine (analog ของ glutathione)
Aspirin Irreversibly inhibits COX by covalent binding, which synthesis of both thromboxane and prostaglandins. Permanent platelet COX-1 inhibition.
Low dose (<300 mg/day): platelet aggregation. Intermediate dose (300-2400 mg/day): antipyretic and analgesic. High dose (2400-4000 mg/day): anti-inflammatory.
Gastric upset. Chronic use can lead to acute renal failure, intestinal nephritis, and upper GI bleeding. Reye’s syndrome in children with viral infection. Avoid in children with acute febrile illness.
COX-2 inhibitors celecoxib
Reversibly inhibit specifically the cyclooxygenase (COX) isoform 2, which is found in inflammatory cells and vascular endothelium and mediates inflammation and pain; spares COX-1, which helps maintain the gastric mucosa. Thus, should not have the corrosive effects of other NSAIDs on the GI lining.
Rheumatoid and osteoarthritis. Risk of thrombosis. Sulfa allergy. Less toxicity to GI mucosa (lower incidence of ulcers, bleeding than NSAIDs).
NSAIDs Ibuprofen Naproxen
Indomethacin ketorolac
Reversibly inhibit COX (both COX-1 and COX-2). Block prostaglandin synthesis.
Antipyretic, analgesic, anti-inflammatory Indomethacin is used to close a PDA (patent ductus arteriosus).
Renal damage, fluid retention, aplastic anemia, GI distress, ulcers.
- Ibuprofen Use: Inflammatory diseases and rheumatoid disorders including juvenile rheumatoid arthritis, mild-to-moderate pain, fever, dysmenorrhea
- Ibuprofen ถกดดซมอยางรวดเรว ภายหลงการรบประทาน ระดบยาสงสดในเลอด ภายในเวลา 1-2 ชวโมง ยาจบกบโปรตนในเลอดไดสงถงรอยละ 99 พบวารอยละ 90 ของยาทไดรบประทานจะถกขบออกทางปสสาวะ ในรปของ hydroxylated และ carboxylated metabolites ขนาดของยาทใชลดการอกเสบคอ 2400 มลลกรมตอวน Note: Should be taken with food
- Naproxen มคาครงชวตยาวกวา ibuprofen (ใหเพยงวนละ 2 ครง) ฤทธตานการอกเสบมากกวา aspirin แตมผลขางเคยงตอทางเดนอาหารนอยกวา Absorption is accelerated by the concurrent administration of sodium bicarbonate but delayed by magnesium oxide or aluminum hydroxide.
- Etodolac (LODINE): Effective in the treatment of osteoarthritis and rheumatoid arthritis and the drug appears to be uricosuric. - TOLMETIN, KETOROLAC, AND DICLOFENAC
- Diclofenac sodium (Dosanac®)
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- Diclofenac is the most commonly used tNSAID in Europe. The selective inhibitor of COX-2 lumiracoxib is an analog of diclofenac. Diclofenac is approved in the U.S. for the long-term symptomatic treatment of rheumatoid arthritis, osteoarthritis, and ankylosing spondylitis.
- Diclofenac มฤทธตานการอกเสบมากกวา aspirin และ naproxen สามารถลดปวดเนองจากนวในทางเดนปสสาวะ Diclofenac ในรปของ topical dosage form ไดน ามาใชในการรกษาอาการตางๆ ไดแก 0.1% ophthalmic preparation เพอปองกนการอกเสบทอาจเกดขนภายหลงการผาตดตาและ 3% topical gel เพอใชในการรกษา solar keratosis
- Tolmetin and ketorolac are structurally related heteroaryl acetic acid derivatives with different pharmalogical features. Diclofenac is a phenylacetic acid derivative that was developed specifically as an anti-inflammatory agent.
- Tolmetin is approved in the U.S. for the treatment of osteoarthritis, rheumatoid arthritis, and juvenile rheumatoid arthritis; it also has been used in the treatment of ankylosing spondylitis.
- Ketorolac (TORADOL, ULTRAM) is used widely in postoperative patients, but it should not be used for routine obstetric analgesia.
Ankylosing Spondylitis Epidemiology: Most common in young men who are HLA-B27 positive Clinical manifestations: Lower back pain and stiffness (especially in morning) owing to fusing of vertebrae; peripheral arthritis of spine and large joints; increase ESR; bamboo spine on radiograph
- Mefenamic acid and Meclofenamate are N-substituted phenylanthranilic acids.
- Mefenamic acid และ Meclofenamate มคาครงชวตสน
- Mefenamic acid and meclofenamate sodium have been used mostly in the short-term treatment of pain in soft-tissue injuries, dysmenorrhea, and in rheumatoid and osteoarthritis. These drugs are not recommended for use in children or pregnant women.
Relifex® - Nabumetone [C;D in 3rd trimester or near delivery]
Relifex is a non-steroidal anti-inflammatory drug of the arylalkanoic acid family (which includes diclofenac). Marketed under the brand name Relafen, it has been shown to have a slightly lower risk of gastrointestinal side effects than most other non-selective NSAID's.
Indication Osteoarthritis & RA requiring anti-inflammatory & analgesic treatment.
Dosage 2 tab daily as a single dose at bedtime.
Cl Active peptic ulceration, severe hepatic impairment.
DI Oral anticoagulant, hydantoin anticonvulsants, sulfonylurea hypoglycaemics.
Ponstan® filmseal tablet - Mefenamic acid [C;D in 3rd trimester or near delivery]
Ponstan is a nonsteroidal, anti-inflammatory agent with analgesic and antipyretic activity in laboratory animals. It is non-narcotic. As with other similar agents, the precise mode of action is not known. However, mefenamic acid was found to inhibit prostaglandin synthesis and to compete for binding at the prostaglandin receptor site in animal studies.
Indication Relief of pain, low back pain, traumatic, post-op or postpartum pain, bursitis, muscular aches & sprains, post dental extraction pain, dysmenorrhea, menorrhagia.
Dosage 500 mg tid
Cl GI ulceration or inflammatory bowel disease. Renal or hepatic impairment.
Binds and stabilizes tubulin to inhibit polymerization, impairing leukocyte chemotaxis and degranulation.
GI side effects, especially if given orally.
Note: indomethacin is less toxic, also used in acute gout
Probenecid (ก)
Chronic gout.
Inhibits reabsorption of uric acid in PCT (also inhibits secretion of penicillin).
Allopurinol (ก)
Chronic gout.
Inhibits xanthine oxidase, conversion of xanthine to uric acid.
Also used in lymphoma and leukemia to prevent tumor lysis-associated urate nephropathy.
concentrations of azathioprine and 6-MP (both normally metabolized by xanthine oxidase). Probenecid and allopurinol should not be used to treat an acute episode of gout. Do not give salicylates. All but the highest doses depress uric acid clearance. Even high doses (5-6 g/day) have only minor uricosuric activity.
- Note: Cyclosporine – Uses: Organ rejection in kidney, liver, heart, & BMT w/ steroids; RA; psoriasis
- Note: Tacrolimus – Uses: Prevent organ rejection, eczema
Treatment of Acute Gout Several tNSAIDs reportedly are effective in the treatment of acute gout. The specific COX-2 inhibitor etorocoxib has been shown to be effective in gout. When effective, NSAIDs should be given at relatively high doses for 3-4 days and then tapered for a total of 7-10 days. Indomethacin, naproxen, sulindac, and celecoxib all have been found to be effective, although the first three are the only NSAIDs that are FDA approved for the treatment of gout. Aspirin is not used because it can inhibit urate excretion at low doses and through its uricosuric actions increase the risk of renal calculi at higher doses.
Prevention of Recurrent Attacks Recurrent attacks of gout can be prevented with use of colchicine (e.g., 0.6 mg daily or on alternate days). Indomethacin (25 mg/day) also has been used. These agent are used in the course of uricosuric therapy when mobilization of urate is associated with a temporary increase in the risk of acute gouty arthritis.
Gout is a metabolic disease most often affecting middle-aged to elderly men and postmenopausal women. Hyperuricemia is the biological hallmark of gout. When present, plasma and extracellular fluids become supersaturated with uric acid, which, under the right conditions, may crystallize and result in a spectrum of clnical manifestations that may occur singly or in combination. โรคเกาตเกดจากการอกเสบเนองจากมผลก monosodium urate monohydrate สะสมในขอ รวมทงในไตและเนอเยออนๆ การสะสมของผลกเกดจากการมกรดยรกในเลอดสง (อาจเกดจาก overproduction หรอ urinary excretion) Etiology and Epidemiology: Caused by joint deposition of urate crystals owing to hyperuricemia.
- Primary: Caused by idiopathic hyperuricemia; risk factors include obesity, alcohol use, and genetic susceptibility; most common in middle-aged men
- Secondary: Owing to hyperuricemia caused by myeloproliferative disorders, decreased urate excretion (renal disease), drugs (ie, diuretics), or Lesch Nyhan syndrome (HGPRT deficiency)
Lab findings: Hyperuricemia, increased ESR, leukocytosis Notes: Pseudogout (pyrophosphate arthropathy) is caused by joint deposition of calcium pyrophosphate crystals (weakly positive, birefringent, rhomboid crystals). It is more common in elderly and usually affects large joints (eg, knee). Uric Acid-Lowering Agents 1. Allopurinol: Decreases uric acid synthesis by inhibit xanthine oxidase. Must be dose-reduced in renal insufficiency. Has significant side effects and drug interactions. 2. Uricosuric drugs (probenecid, sulfinpyrazone): Increases uric acid excretion by inhibiting its tubular reabsorption; ineffective in renal insufficiency; should not be used in these settings: age> 60, renal stones, tophi, increased urinary uric acid excretion, cytotoxic therapy prophylaxis.
ยารกษาโรคขอเสอม (Drugs used in osteoarthritis) Osteoarthritis (OA) is a disorder characterized by progressive joint failure in which all structures of the joint have undergone pathologic change. The pathologic sine qua non of OA is hyaline articular cartilage loss accompanied by increasing thickness and sclerosis of the subchondral bone plate, outgrowth of osteophytes at the joint margin, stretching of the articular capsule, and weakness of the muscles bridging the joint. There are numerous pathways that lead to OA, but the initial step is often joint injury in the setting of a failure of protective mechanisms. โรคขอเสอม หรอ degenerative joint disease เปนโรคขอทพบมากทสด โดยเฉพาะผ มอาย > 60 ป เพราะเกยวของกบการเสอมของขอตามวย นอกจากอายแลว ปจจยเสยงอนๆ ไดแก obesity, osteoporosis, smoking, การใชงานขอตางๆมากเกนไปม การไดรบบาดเจบทขอ (joint trauma) เปนตน ลกษณะของขอทเปน OA คอ ผดรปราง (deformity) มการเคลอนไหวจ ากดซงเกดขนอยางชาๆ กระดกออนในขออาจบวมหนาเนองจากการอกเสบแตตอมาจะแตกและบางลง Investigations in OA Blood test. There is no specific test; the ESR is normal although high sensitivity CRP may be slightly raised. Rheumatoid factor
and antinuclear antibodies are negative. X-rays are abnormal only when the damage is advanced. They are useful to assess severity for operative intervention for knees,
a standing X-ray(stressed) is used to assess cartilage loss and ‘skyline’ views in flexion for patella-femoral OA MRI demonstrates meniscal tears, early cartilage injury and subchondral bone changes. Arthroscopy reveals early fissuring and surface erosion of the cartilage.
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Aspiration of synovial fluid (if there is a painful effusion) shows a viscous fluid with few leucocytes and occasionally calcium pyrophosphate crystals
Note: Leucovorin [C]: Antidote; Vitamin, Water Soluble Use: Antidote for folic acid antagonist (MTX, trimethoprim, pyrimethamine); treatment of megaloblastic anemias when folate is deficient as in infancy, sprue, pregnancy, and nutritional deficiency when oral folate therapy is not possible; in combination with fluorouracil in the treatment of colon cancer Contraindications: pernicious anemia or vitamin B12 – deficient megaloblastic anemias
Leflunomide [X] เมดละ 86-87 (ป44)
ARAVA®
ยบยง dihydroorotate dehydrogenase ยบยงการสงเคราะห pyrimidine ยบยงการเจรญของเซลล mononuclear และ T lymphocyte
กระตน latent tuberculosis เพมขน, การสราง antietanercept antibodies AR: Mild to moderate inj site reaction, infection, allergic reactions, fever, pruritus
I: RA, juvenile chronic arthritis, psoriatic arthritis, ankylosing spondylitis CI: Pts w/sepsis or risk of sepsis. Serious active infection including chronic or localized infection
Tumor Lysis Syndrome When rapidly growing tumors are treated with effective chemotherapy regimens, the dying tumor cells can release large amounts of nucleic acid breakdown products (chiefly uric acid), potassium, phosphate, and lactic acid. The phosphate elevations can lead to hypocalcemia. The increased uric acid, especially in the setting of acidosis, can precipitate in the renal tubules and lead to renal failure (hyperuricaemic nephropathy). The renal failure can exacerbate the hyperkalemia.