Musculoskeletal,skin,and connective tissue drugs Flashcards
Membrane phospholipids to arachidonic acid - pathways (and steps)
2 pathways:
1. (leukotriene synthesis) arachidonic acid –> 5-HPETE
(5-lipoxygenase) –> Leukotrienes
2. (endoperoxide synthesis) arachidonic acid –> cyclic endoperoxides (COX1/2) –> prostacyclin/prostagladins/thromboxane
5-HPETE
5-hydroperoxyeicosatetraenoic acid
Leukorienes - types and action
LTB4–> increased neutrophil chemotaxis
LTC4 –> increased bronchial tone
LTD4 –> increased bronchial tone
LTE4 –> increased bronchial tone
5-Lipoxygenase inhibitor
Zileuton
Zileuton - clinical use / side effects
asthma
SE: hepatotoxicity
Leukotriene receptor antagonists (which receptor)
Montelukast
Zafirlukast
(LTC4, LTD4, LTE4)
Montelukast, Zafirlukast - clinical use
aspirin-induced asthma
Thromboxane - types and action
TXA2 –> increased aggregation, increased vascular tone
COX -2 inhibitor (only)
celecoxib
COX - 1/2 inhibitor
ASPIRIN (irreversible) and other NSAIDs
Membrane phospholipids to arachidonic acid - pathways
- leukotriene syntehsis
2. Endoperoxide synthesis
Prostacyclin types and action
PGI2 –> decreases aggregation and vascular tone (vasodilation)
Prostagladins types and action
PGE1 –> decrease vascular tone (vasodilation)
PGE2 –> increases uterine tone
PGF2 –> increases uterine tone
PGI2 is a
prostacyclin
TXA2 is a
thromboxane
PGI2 analog
epoprostenol
iloprost
PGE1 analog
alprostadil
PGE2 analog
Dimopristone
PGF2 analog
carboprost
acetaminophen - mechanism of action
reversible inhibits cycloxygenase, mostly in CNS. INACTIVATED PERIPHERALLY
acetaminophen action in periphery
INACTIVATED PERIPHERALLY
clinical use of acetaminophen
antipyretic and analgesic
NOT ANTI - INFLAMMATORY
acetaminophen action against inflammation
NOT ANTI - INFLAMMATORY
acetaminophen vs aspirin in children with viral infection
acetaminophen is used to avoid Reye syndrome
acetaminophen toxicity
overdose produce hepatic necrosis
acetaminophen toxicity - mechanims
overdose –> acetaminophen metabolite (NAPQI) depletes glutathione and forms toxic tissue byproducts in liver –> hepatic necrosis
antidote of acetaminophen toxicity and mechanism
N-acetylcysteine –> regenerates glutathione
N-acetylcysteine -clinical use
- cystic fibrosis (mucolytic)
2. antidote of acetaminophen toxicity
acetaminophen - reversible or irreversible inhibition of COX
REVERSIBLE
Aspirin - mechanism of action
irreversible inhibits COX (both 1/2) via covalent acetylation, which decreases synthesis of TXA2 and prostaglandins. Effects lasts until new new platelets produced
ITS A TYPE OF NSAID
Aspirin - PT, PTT
no effect
Aspirin - bleeding time
increased
Clinical use of aspirin (and doses)
Low dose, under 300 (inhibits platelet aggregation) Intermediate dose (300-2400mg/day) --> antypyretic and analgesic High dose (2400-4000mg/day) --> anti-inflammatory
Aspirin - side effects
- Gastric ulceration 2. tinnitus (CN VIII)
3. Acute renal failure (chronic use) 4. interstitial nephritis 5. GI bleeding 6. Reye syndrome 7. pH disturbances
Aspirin - pH disturbances
respiratory alkalosis early (hyperventilation)
transition to mixed metabolic acidosis-respiratory alkalosis
COX-2 - area
inflammatory cells and vascular endothelium
COX-2 mediates
inflammation and pain
Celecoxib - mechanism of action
reversible inhibition of COX-2 (only)
Celecoxib spares COX-1 - clinical importance
maintain gastric mucosa
celecoxib vs other NSAID according side effects
celecoxib does not have the corrosive effects of ther NSAID on the GI lining
beside gastric mucosa, celecoxib spares …. function (why)
it spares platelet function as TXA2 production is depended on COX-1
TXA2 production is depended on
COX-1
NSAID - drugs
- ibuprofen 2. naproxen 3. indromethacin 4. ketorolac 5. diclofenac 6. meloxicam 7. piroxicam
NSAID - mechanism
REVERSIBLE inhibit cyclooxygenase (both COX 1 and 2)
–> block prostaglandin synthesis
clinical use of NSAID
- antipyretic 2. analgesic 3. anti-inflammatory
4. Indomethacin is uded to close PDA
toxicity of NSAID
- interstitial nephritis 2. gasrtic ulcers 3. renal ischemia
NSAID can cause renal ischemia - mechanism
prostagladins vasofilate afferent arteriole
Bisphosphonates - drugs
alendronate and other -DRONATES
Bisphosphonates - mechanism
pyrophosphate analogs –> hydroxyapatite in bone –> inhibition of osteoclasts
Bisphosphonates - clinical use
- osteoporosis
- hypercalcemia
- Paget disease of bone
- metastatic bone disease
- osteogenesis imperfecta
Teriparatide - mechanism of action
Recombinant PTH analog –> increases osteoblastic activity
Teriparatide - administration
subcutaneously/daily
Teriparatide - clinical use (explain)
osteoporosis –> causes increased growth compared to antirepsorptive therapies (eg. biphosphanates)
Teriparatide - toxicity
- transient hypercalcemia
2. May increase risk of osteosarcoma (seen in rodent studies)
TNF-a inhibitors - drugs and mechanism of action
- etanercept - fusion protein (receptor for TNF-A+IgG1 FC) produced by recombinant DNA
- infliximab - anti-TNF-a monoclonal antibody
- adalimumab - anti-TNF-a monoclonal antibody
- certolizumab - anti-TNF-a monoclonal antibody
all TNF-a inhibitors predispose to
infection, including reactivation of latent TB
TNF-a inhibitors predispose to TB reactivation - mechanism
TNF is important in granuloma formation and stabilization
infliximab - mechanism of action
anti-TNF-a monoclonal antibody
abalimunab - mechanism of action
anti-TNF-a monoclonal antibody
Etanercept - mechanism of action
fusion protein (receptor for TNF-A+IgG1 FC) produced by recombinant DNA
Etanercept - clinical use
- Rheumatoid arthritis
- psoriasis
- ankylosing spondylitis
infliximab and adalimumab - clinical use
- inflammatory bowel disease
- rheumatoid arthritis
- ankylosing spondylitis
- psoryasis
bisphosphonates - side effects
- corrosive esophagitis (patients are advised to take with water and remain upright for 30 mins)
- osteonecrosis of jaw
bisphosphonates - vs Teriparatide according action on osteoporosis
bisphosphonates –> anti-resorptive
Teriparatide –> induce bone growth
celecoxib - side effects
- increased risk of thrombosis
2. sulfa allergy
celecoxib - clinical use
- Rheumatoid arthritis
2. osteoarthritis
Rasburicase - mechanism of action
Recombinant uricase that catalyzes metabolism of uric acid to allanotin
Rasburicase - clinical use
Prevention and treatment of tumor lysis syndrome
Rasburicase - mechanism of action / clinical use
Recombinant uricase that catalyzes metabolism of uric acid to allanotin
Clinical use: Prevention and treatment of tumor lysis syndrome
Leflunamide - mechanism of action
Reversibly inhibits dihydroorotate dehydrogenase –> prevent pyrimidine synthesis –> suppresses T-cell proliferation
Leflunamide - clinical use
- RA
2. psoriatic arthritis
Leflunamide - adverse effect
- Diarrhea
- hypertension
- hepatotoxicity
- teratogenicity