Others Flashcards
What size do particles need to be in order to be efficiently nebulized to the alveoli? What is the unit used?
Between 0.5 - 5 um
Unit is MMD = mass median diameter = particle sizes above and below which 50% of the mass of particles is contained
What are the different types of delivery systems for inhaled medications
- Jet nebulizers: high-velocity stream of gas (O2) travelling through the medicated solution to comminuted the liquid into an aerosol, then delivered to patient through a spacer and face mask (ideally with one-way inspiratory valve)
- Ultrasonic and mesh nebulizers: similar to jet nebulizers but use ultra-high-frequency oscillations or a vibrating aperture plate to aerosolize the liquid
-> don’t need a high velocity of gas and produce smaller size particles more consistently - Metered dose inhalers: measured dose of medication propelled through nozzle at high velocity to form a spray then delivered through spacer and face mask
What are the 2 main families of bronchodilators and their mechanism of action? What other drugs can cause bronchodilation
- Beta-agonists (terbutaline, albuterol = salbutamol)
Stimulation of beta2-adrenergic receptors on bronchi smooth muscle cells -> cAMP pathway (Gs receptor) -> protein kinase activation -> smooth muscle relaxation - Methylxanthines derivatives (theophylline, aminophylline)
Non-specific phosphodiesterase inhibitors -> increased cAMP and cGMP -> relaxation of bronchi smooth muscle + decreased inflammation - Others:
- Anticholinergics (inhibit vagally-mediated bronchoconstriction)
- Calcium antagonists
What nebulized treatment can be used for the treatment of infectious tracheobronchitis in dogs
Gentamicin (efficient for B bronchiseptica)
6-7 mg/kg diluted 1:3 with saline nebulizer for 5-10 min q8-12h for at least 3 days
To what chemotherapeutic agents do dogs with the ABCB1 (MDR1) mutation have increased sensitivity
- Doxorubicin
- Vinblastine, vincristine
What is produced secondary to the catabolism of purines in acute tumor lysis syndrome
Uric acide (purines -> hypoxanthine -> xanthine -> uric acid)
What chemotherapeutic carries a high risk of anaphylactic reaction
L-asparaginase
What are the main adverse effects of tyrosine kinase inhibitors (eg. toceranib)
- GI with potential GI ulceration / bleed
- Renal toxicity
- Possible hepatic toxicity
When does the neutrophil nadir usually happen following chemotherapy? What are some exceptions?
Usually 7-10 days
Carboplatin: 10-14 days and 21 days
Lomustine: 7-28 days
Name 2 chemotherapeutics causing severe tissue injury in case of extravasation. What drugs can be administered to mitigate the effects
- Doxorubicin ->apply cold packs and administer IV dexrazoxane at 10 times the extravasated dose (within 3-6h, at 24h, and at 48h)
- Vinca alkaloids (vincristine, vinblastine) -> apply warm compresses and administer perilesional hyaluronidase (1mL for everyone 1mL of drug extravasated)
Associate these chemotherapeutic agents:
- lomustine (CCNU)
- cyclophosphamide
- doxorubicin
- 5-fluorouracile
- cisplatin
- L-asparaginase
- toceranib
with these adverse effects:
- hemorrhagic cystitis
- hypersensitivity
- nephrotoxicity
- hepatotoxicity
- pancreatitis
- neurotoxicity
- cardiotoxicity
- pulmonary toxicity
(several possible associations)
- Lomustine -> hepatotoxicity, pulmonary toxicity (pulmonary fibrosis - rare)
- Cyclophosphamide -> hemorrhagic cystitis
- Doxorubicin -> cardiotoxicity, nephrotoxicity in cats
- 5-fluorouracile ->neurotoxicity (never use in cats!)
- Cisplatin -> nephrotoxicity, pulmonary toxicity in cats (never use)
- L-asparaginase -> hypersensitivity, pancreatitis
- Toceranib -> nephrotoxicity
List some actions of glucocorticoids on inflammation / immune system
- Inhibit phospholipase A2 -> no release of arachidonic acid -> no initiation of cascade (decreased prostaglandins)
- Possible direct inhibition of COX-2
- Inhibition of transcription of NF-kb
- Inhibition of transcription of several cytokines (IL-1, IL-6, IL-2, IL-8, TNF-alpha, IFN-gamma)
- Downregulation of cell adhesion molecules (ICAM-1, E-selectin)
- Inhibition of iNOS
- Downregulation of Fc receptor expression on macrophages
Compare the glucocorticoid and mineralocorticoid potency of cortisol, hydrocortisone, prednisone, dexamethasone, fludrocorstione, aldosterone
See table
Mechanism of action of cyclosporine
Calcineurin inhibitor
Binds cyclophilin (cytoplasmic receptor) -> binds to calcineurin -> inhibits transcription of T cell genes, inhibits expression of IL-2
+ directly inhibits IL-3, IL-4, IL-5, IL-8, and TNFα
Mechanism of action of mycophenolate mofetil
Inhibitor of inosine monophosphate dehydrogenase (IMPDH) -> inhibit synthesis of purines -> inhibit production of GMP -> anti-metabolite targeting B cells and T cells (prevent proliferation and immunoglobulin synthesis)
