Medications Flashcards
Fluoroquinolones
Inhibits DNA gyrase
Examples: Ciprofloxacin, levofloxacin
Clinical importance: Ppx for leech treatment ( can–> hydromonas infection), and open fractures associated with water (pseudomonas); increased tendon rupture risk, may inhibit fracture healing
Penicillins
inhibit cell wall synthesis via transpeptidase inhibition
Clinical Importance: add for open fractures with farm/gross contamination –> prevent clostridium infection
Cephalosporins
inhibit cell wall synthesis via transpeptidase inhibition
Miscellaneous Cell Wall Inhibotors
Vanco, carbapenems
MOA: vanco inhibits peptidoglycan crosslinking
Clinical importance: vanco–>redman syndrome, nephrotoxicity
aminoglycosides (tobra and gent), tetracyclines (doxy)
anti 30s ribosome
Irreversible inhibitor. gent is notable for OTOtoxicity, limited evidence to suggest adding for grade III open fractures, tetracylcines can cause skin and tooth discoloration (avoid in kids <8 and pregnancy)
macrolides (azithromycin), clinda, linezolid
anti 50s ribosome
clinda can cause pseudomembranous colitis from c diff. D- zone test tests for inducible resistance to clinda. If positive must change to another abx.
Direct Thrombin (factor IIa) inhibitor
Dabigatran (Pradaxa)
Argatroban
Hirudins
Hirudins
Hirudins from leeches. Antidote is Praxbind (idarucizumab) or activated prothrombin complex concentrates (aPCC)
Direct Xa inhibitor
RivaroXaban (Xarelto)
ApiXaban (Eliquis)
EdoXaban (Savaysa)
Renal excretion. Antidote is andexanet
Indirect Xa inhibitor
Fondiparinux (Arixtra)
Enoxaparin (Lovenox)
Heparin
Fondiparinux (Arixtra)
activates antithrombin III, highly selective for factor X
Enoxaparin (Lovenox)
activates antithrombin III; intermediate selectivity for factor X (some thrombin inhibition)
Heparin
activates antithrombin III–> inhibit thrombin; but also indirectly inhibits inhibits factor IX, X, XI as well (not very discriminant)
Classic reversal agent for heparin is protamine sulfate.
Fondiparinux (Arixtra)
Enoxaparin (Lovenox)
Heparin
Beware of HIT (delayed onset thrombocytopenia plus arterial and venous hypercoaguable state) w/ heparin (risk far lower w/ fond and enox). This is due to development of antibodies to PF4 (platelet factor 4)
Classic reversal agent for heparin is protamine sulfate.
Enox and fonda are renally excreted (beware w/ CrCl<30), heparin is hepatically cleared.
Coumadin (warfarin)
Inhibits the vitamin K dependent enzyme epoxide reductase in the liver impairing the activation of clotting factors 2, 7, 9, 10, as well as ANTI-clotting factors protein C and S.
Coumadin Info
Efficacy monitored w/ INR (target 2-3). Extremely long half life. Reverse fx w/ vitamin K injection or w/ FFP for rapid INR correction. Multiple drug interactions (green tea and st johns wort–>clots; omega 3 fish oil–>bleeding).
Herbals causing bleeding
gingko
gingsing
garlic
All three have antiplatelet effects and can increase bleeding risk
Tranexamic acid
FIBRINOLYTIC
Competitive inhibitor of plasminogen (precursor to plasmin which lyses fibrin-factor Ia-clots) at lower dose and direct plasmin inhibitor at high dose
Most commonly used in arthroplasty and now spine. Few adverse events. Can be used intravenously and topically in severe renal dz (renally excreted).
Non-nitrogen containing bisphosphonate
Etindronate, Clodronate
Bind to bone minerals and taken up by osteoclast DIRECTLY and cause apoptosis via formation of toxic ATP analogue
Original bisphosphonate. 1000x LESS potent than current agents (N-containing).
Nitrogen containing bisphosphonate
Pamindronate, Alendronate, Zolendronic acid, Rosendronate
MOA: Inhibits N-farnesyl pyrophosphate Synthase–>loss of GTPase function and osteoclast cell death
In general, side effects include GI upset/GERD (most common), osteonecrosis of the jaw (rare), and atypical subtroch fractures (low energy, hypertrophic lateral cortex, no comminution, medial spike, transverse pattern). Zolendronate given as IV infusion once yearly. Should only be given for 5-8 years before stopping.
Raloxifene
Estrogen receptor agonist
Less commonly used for osteoporosis. Acts directly on osteoclasts.
Teriparatide
PTH analogue that acts directly on osteoblast –> reduced RANKL production (when used at pulsed intervals)
Contraindicated in Pagets disease owing to risk of secondary osteosarcoma.
Denosumab
OPG mimic that inhibits RANKL binding by binding and sequestering RANKL. (as opposed to competing for it’s binding site)
Used also in GCT (in addition to osteoporosis)
Romosozumab
Sclerostin antibody
Early phases, may aid fixation into osteoporotic bone.
