Exam Flashcards
Indomethacin MOA
Non-selective inhibitor of COX 1 and 2
More potent than aspirin
Febuxostat use
Alternative to allopurinol
Approved for hyperuricemia with gout attacks
Colchicine MOA
- not well understood
- anti-mitotic effects: interferes with microtubule (B-tubulin polymerization) formation that disrupts function of neutrophil cytoskeleton
- prevents activation, degranulation and migration of neutrophils associated with mediating gout symptoms
Leflunomide PK
- orally effective, QD
- prodrug converted to teriflunomide
- extremely long half-life, with significant consequences (due to repeated enterohepatic recirculation, active agent can remain in body for long time, choelestyramine can be used to clear)
MTX side effect in triple therapy
Multiple drugs with synergistic effects
Reduced side effects compared to increasing dose of any one drug
Abatacept use and MOA
- CD28 receptor antagonist —> T cell activation inhibitor
- moderate to severe RA that is not responsive to other DMARDs
Effect of pH on local anesthetic potency
- local anesthetics are a weak base
- non-ionized = lipid soluble
- ionized = water soluble
- greater lipid solubility of a drug enhances potency and enable more rapid diffusion
- acidic environment with antagonize the block
Bupivacaine lipid solubility and potency
- high hydrophobic, fast onset, highly potent —> highly lipid soluble
- long DOA; epidural 2-7 hours, infiltration 2-8 hours, dental up to 7 hours
- spinal, epidural, peripheral nerve block, infiltration anesthesia
Local anestetic MOA
- block Na channels in excitable tissues and prevent signal transmission along nerves
- block AP from moving down nerve —> block nerve firing
- requires a small area of blockage (~3 nodes of ranvier)
BZDs as muscle relaxants via GABA-A —> used to treat spasicity
- GABA-A agonist
- increase frequency of channel opening and Cl conductance —> hyperpolarized state
- adjunct to baclofen for spasticity treatment
- manage seizures caused by local anesthetic overdose
Orphenadrine MOA —> used to treat spasms
- exact MOA not known
- indirect skeletal muscle relaxant works by central atropine-like effects
- anticholinergic
- antihistamine effects
- some euphorigenic and analgesic properties
- treat muscle spasms including lumbago and sciatica
Tizanidine drug interaction with clonidine
- drug interactions with CNS depressants, clonidine or other anti-HTN (both alpha2 agonists) —> additive effect
Partial pressure definition
GO BACK AND ADD
Lipid theory of general anesthetic action
- classical theory: lipid solubility
- reversible interaction of agent with neuronal membrane lipids; came from recognition that anesthetic potency roughly correlates with oil:water partition coefficients of individual agents
- no longer accepted
Current theory: anesthetics reversibly interact with hydrophobic sites of specific membrane proteins, altering signal transduction pathways
MAC definition
- minimum alveolar concentration —> definition of inhalation anesthetic potency
1 MAC = alveolar partial pressure that prevents movement in 50% of adult patients in response to standard painful stimulus
MAC is inversely proportional to lipid solubility of agent (high MAC; low solubility)
1.3 MAC is ED95; usually during surgery
Additive when co-administered
Decreases 6% per decade of age
Increase MAC (decrease potency): infancy, chronic alcohol intake, hypernatremia Decrease MAC (increase potency): elderly, acute alcohol intake, pregnancy, opioids
