THE SECOND COMING OF METHOXYFLURANE

Ⓜ️Initially developed as an inhalational anesthetic, but withdrawn due to concerns about nephrotoxicity and hepatotoxicity. 

Ⓜ️In view of its analgesic properties it is now used, mainly in Australia and New Zealand, to provide short-term analgesia for painful procedures and in the prehospital setting (Grindlay and Babl, 2009). 

Ⓜ️Administration is via a dedicated single-use inhaler dispensing 0.2–0.4% methoxyflurane. 

Ⓜ️The limited data on efficacy suggest that methoxyflurane administered as a single dose as described above provides effective analgesia resulting in high patient satisfaction with no evidence of toxicity (Grindlay and Babl, 2009). 

Ⓜ️There is no good evidence regarding the safety of repeated doses, for example, for analgesia during daily dressing changes.

Ref: 

Acute Pain Management; A Practical Guide, Pamela E. Macintyre , Stephan A. Schug, 4/e

NSAIDS-COMPARISON

ANTI INFLAMMATORY PROPERTIES 

〰〰〰〰〰〰〰〰〰〰〰〰〰

✨BETTER THAN NAPROXEN :

🔹Flurbiprofen

🔹Indomethacin

✨GOOD:

🔹Naproxen

🔹Fenoprofen

🔹Ketoprofen

🔹Tiaprofenic acid

🔹Diclofenac

🔹Aceclofenac

🔹Etodolac

🔹Nabumetone

🔹Piroxicam

🔹Tenoxicam

🔹Etoricoxib

✨WEAK:

🔹Ibuprofen

🔹Mefenamic acid

SIDE EFFECTS 

〰〰〰〰〰

✨FEWER SIDE EFFECTS 

🔹 Ibuprofen 

✨GREATER THAN IBUPROFEN

🔹 Naproxen

🔹 Fenoprofen(GI)

🔹 Flurbiprofen(GI)

🔹 Ketoprofen

🔹 Diclofenac

🔹 Aceclofenac

🔹 Sulindac

🔹 Tenoxicam

✨HIGH

🔹 Indomethacin

🔹 Piroxicam 

✨HIGH RISK OF RASH

🔹 Fenbufen

✨SEVERE CYSTITIS

🔹 Tiaprofenic Acid

✨DIARRHOEA & HEMOLYTIC ANEMIA

🔹 Mefenamic acid

✨LOW G.I.; BUT HIGH C.V. EFFECTS

🔹 Celecoxib

🔹 Etoricoxib

Reference: 

Medicines Optimisation Academy 

British National Formulary

PAIN IN GUILLAIN BARRE SYNDROME

✔️GBS a number of different subtypes

✔️The most common is an acute inflammatory demyelinating polyradiculoneuropathy 

✔️More than half of patients report severe pain. 

✔️Severe widespread neuropathic pain may be described, often without the features of a peripheral neuropathy, as well as musculoskeletal pain. 

✔️May sometimes have severe acute pain, 

✔️Treatment with systemic ketamine and/or lidocaine as well as gabapentin/pregabalin and carbamazepine may be of benefit in the acute phase (ANZCA and FPM, 2010).

Ref: Acute Pain Management: A practical guide,4/e, Pamela E. Macintyre , Stephan A. Schug

ADVERSE EFFECTS OF UNDER TREATED SEVERE ACUTE PAIN

(Reference: Pamela E. Macintyre,Stephan A. Schug. ACUTE PAIN MANAGEMENT; A PRACTICAL GUIDE)

👹Tachycardia, hypertension

👹increased myocardial oxygen consumption, myocardial ischemia

👹 Decreased lung volumes, atelectasis, decreased cough, sputum retention, infection, hypoxemia

👹Decreased gastric and bowel motility 

👹Urinary retention 

👹Increased catabolic hormones: glucagon, growth hormone, vasopressin, aldosterone, renin, and angiotensin 

👹Reduced anabolic hormones: insulin, testosterone 

👹Catabolism leads to hyperglycemia, increased protein breakdown and negative nitrogen balance; ➡️impaired wound healing and muscle wasting 

👹 Muscle spasm, immobility (increasing risk of deep-vein thrombosis-->pulmonary embolism) and muscle wasting 

👹 Chronic (persistent) pain due to central sensitization 

👹 Anxiety, fear, helplessness, sleep deprivation—leading to increased pain and potential long-term psychological effects