ORTHOPAEDIC DRUGS

Paracetamol : first line drug, safe NSAIDs : unresponsive to paracetamol. COX-2 inhibitors or NSAIDs + PPI in GI risk Topical agents (NSAIDs, capsaicin): safe and effective in mild pain Opiod : patients contraindicated for NSAIDs or COX-2, or ineffective or poorly tolerated Anticonvulsant (Gapapentin, Pregabalin) benefit in neuropathic pain

 Acetaminophen (Paracetamol) Effective step 1 analgesic. Also useful as a co-analgesic. CNS blocking mechanism. No anti-inflammatory effects.

 Acetaminophen– Adverse effects Doses >4 g/day may cause hepatotoxicity . Hepatic disease or heavy alcohol user increase risk for hepatotoxicity. Avoid combine paracetamol with these drugs (and advice patient not to buy from drug store) Norgesic Muscol Ultracet Other drug contain paracetamol

NSAIDs Non-steroidal anti-inflammatory drugs Is a drug group that is not a steroid but has three effects together Analgesic effect Antipyretic effect Anti-inflammatory effect Therefore, it reduce pain, fever and inflammation

 Effect of NSAID to COX 1&2

COX-1 and COX-2

Prostaglandins Arachidonic acid Conventional NSAIDs Prostaglandins Impaired platelet function  Inflammation, pain, and fever กลไกการออกฤทธิ์ของ NSAIDs COX-2 COX-1 Thromboxane Gastrointestinal toxicity COX; 2 Isoforms X X

Prostaglandins Arachidonic acid COX II inhibitors Prostaglandins Impaired platelet function กลไกการออกฤทธิ์ของ NSAIDs COX-2 COX-1 Thromboxane Gastrointestinal toxicity COX; 2 Isoforms X  Inflammation, pain, and fever

 NSAIDs Conventional NSAIDs Aspirin, ASA (Aspent) Indomethacin (Indocid) Ibuprofen (Brufen) Naproxen (Naprosyn, Synflex) Diclofenac (Voltaren) Mefenamic acid (Ponstan) Piroxicam (Feldene) 16. NSAIDs  Preferential COX II Inhibitors Meloxicam (Mobic) Nimesulide (Nidol) Selective COX II Inhibitors Celecoxib (Celebrex) Etoricoxib (Arcoxia) Parecoxib- [injection] (Dynastat)

Conventional NSAIDs Proprionic acid derivatives ibuprofen, naproxen, ketoprofen, loxoprofen Ibuprofen 400 Naproxen 275

Conventional NSAIDs Acetic acids derivatives indomethacin, diclofenac Indomethacin 25 Voltaren 25 Voltaren SR 75

Fenamic acid derivatives mefenamic acid Conventional NSAIDs Ponstan 250

Oxicams piroxicam, tenoxicam Conventional NSAIDs Feldene 10 Feldene 20 Ticotil 20

 Preferential COX 2 inhibitors Nimesulide (Nidol) Meloxicam (Mobic)

 Selective COX 2 inhibitors Celecoxib (Celebrex) Etoricoxib (Arcoxia) Celebrex 200 Arcoxia 60

Side effects of NSAIDs GI disturbance Renal disturbance Impair platelet function CNS and ANS disturbance Liver toxicity Pulmonary system Skin lesion Drug interaction

24. Non specific cox-inhibitor Long term use and long term safety is studied Believed to be safer than cox-2 inhibitor in terms of cardiovascular risk But increase GI risk Edema and renal insufficiency might occur at long term usage Aware in old age, renal insuff, long term usage, and history of GI ulcer

 Awareness in NSAIDs Old age High GI risk Poor renal function Poor liver function Asthma Pregnancy Lactation

Dosage Ibuprofen (200,400) 1 tab PO bid or tid pc (Brufen, Heidi) Diclofenac (25) 1 tab PO tid pc (Voltaren) Naproxen (275) 1 tab PO bid pc Meloxicam (7.5) 1 tab PO OD (Mobic, Melox) Celecoxib (200, 400) 1 cap PO OD (Celebrex) Etoricoxib (60, 90, 120) 1 tab PO OD (Arcoxia)

Muscle relaxant Indication -Muscle spasm, Reduction Precaution -Constipation -Water retention -Specific action of each muscle relaxants : Atropine like effect (orphenadine), peripheral Vasodilatation (tolperisone)

Muscle relaxant Somewhat helpful in soft tissue injury, muscle strain, myofascial pain With or without paracetamol Should not operate any machine or driving after taking the medicine (from possibility of drowsiness) Aware in old age , BPH , closed-angle glaucoma

Muscle relaxant Carisopodal : Alaxan, carisoma Chlorzoxazone : Parafon forte Eperisone : Myonal Methocarbamol : Robaxin Orphenadine : Norgesic, Muscol Tizandine : Sirdalud Tolperizone : Mydocalm