Pharmacology Flashcards
MOA, side effects of cimetidine, famotidine, ranitidine
MOA: H2 receptor antagonists —> decrease H+ secretion and Pepsi open secretion. Cimetidine also has immunomodulatory effects. Ranitidine also has prokinetic effects (acetylcholinesterase inhibitor)
Side effects: bradycardia, hypotension, arrhythmias (with rapid IV admin); cytopenia with cimetidine
MOA, side effects of omeprazole, pantoprazole, esomeprazole
PPIs - inhibits H+/K+ ATPases on parietal cells
SE: diarrhea
MOA, side effects of misoprostal
MOA: synthetic PGE1 analog
SE: GI upset, uterine contractions, vaginal bleeding
Exposure risk to female owners
MOA, side effects of sucralfate
MOA: reacts with HCl in stomach forming a paste-like complex that binds the protein across exudates at ulcer sites —> creates a physiochemical barrier
SE: generally well-tolerated, rarely constipation
Considerations: best given on an empty stomach and separated from other drugs by two hours.
**Impairs absorption of antacids, ciprofloxacin, digoxin, ketoconazole, levothyroxine, macrolides, penicillamine, tetracyclines, theophylline, fat soluble vitamins, and warfarin
MOA, side effects of true antacids (calcium carbonate, sodium bicarbonate, magnesium salts, aluminum salts, and phosphate binders)
MOA: inorganic, relatively insoluble starts that partially neutralize gastric HCl when dissolved in the stomach (however large doses are needed to raise pH significantly)
SE: generally well tolerated
MOA, side effects of amyloid pine
MOA: calcium channel blocker —> results in peripheral arterial dilation with minimal cardiac effects
SE: reversible gingival hyperplasia, hypotension, bradycardia, inappetence
When used for hypertension, what magnitude of blood pressure reduction would you expect when giving amlodipine with an ACEi vs. ARB?
ACEi: 30-70mmHg
ARB: 10-20mmHg
MOA and side effects of enalapril and benazepril
MOA: angiotensin converting enzyme (ACE) inhibitor
SE: GI upset, hypotension, weakness, azotemia, and hyperkalemia
Enalapril has __ excretion
Benazepril has __ excretion
Enalapril = renal
Benazepril = hepatic
Benazepril may be preferred in cats with renal disease
MOA, side effects of telmisartan
MOA: angiotensin-II receptor blocker (ARB) - specifically blocks type 1 receptor (with 3000x more affinity than type 2)
Side effects: GI upset, hypotension, weakness, azotemia, hyperkalemia
MOA and side effects of atenolol
MOA: Beta-1 blocker
SE: diarrhea, inappetence, lethargy, bradycardia, hypotension, impaired AV condition, congestive HF, bronchoconstriction (less so with Beta-1 specific drugs), syncope
Amphotericin B is fungiSTATIC/CIDAL and concentration DEPENDENT/INDEPENDENT
Fungicidal
Concentration DEPENDENT
Spectrum, side effects of amphotericin B
Spectrum: broad spectrum (most systemic fungal infections, disseminated sporotrichosis, candidiasis, aspergillosis)
Side effects: nephrotoxicity in >80% of patients; anaphylaxis, fever, vomiting, anorexia, thrombophlebitis, hepatic dysfunction
**Newer formulas are available that increase hydrophobicity —> increased delivery to target site with decreased delivery to kidney
Polyenes antifungals and MOA
Amphotericin B
Nystatin, natamycin
MOA: interference with cell membrane function by binding ergosterol, forming pores in the fungal cell membrane which alters permeability
Spectrum of nystatin and natamycin
Broad spectrum
Route of administration of amphotericin B vs. nystatin
Amphotericin B = IV
Nystatin = topical
Azole antifungals and MOA
Types: Ketoconazole, itraconazole, fluconazole, voriconazole, posiconazole
MOA: inhibition of cell membrane (ergosterol) synthesis
Azoles are fugniCIDAL/STATIC
Fungistatic
Spectrum and side effects of ketaconazole
Spectrum: topical mycotic infections (dermatology ties), Malassezia, dimorphism fungi (cryptococcosis)
Side effects: GI signs, hepatotoxicity (mild to moderate increases in ALT), ataxia, alopecia; can block cholesterol, cortisol, and androgen synthesis; lightening of hair coat
Spectrum and side effects of itraconazole
Spectrum: broad (most fungal diseases)
SE: GI signs, hepatotoxicity, vasculitis/ulcerative skin lesions
**No blockage of adrenal steroid or testosterone synthesis compared to ketoconazole
Which azole can reach the CSF?
Fluconazole
Spectrum and side effects of fluconazole
Spectrum: most candida, dermatophytes, dimorphic fungi (cryptococcus, coccidiomycosis, histoplasmosis, blastomycosis)
Side effects: GI signs and mild elevation in liver enzymes
Spectrum and side effects of voriconazole
Spectrum: wide
SE: teratogenic, GI upset, hepatotoxicity
Spectrum and side effects of posaconazole
Spectrum: wide
SE: GI upset, hepatotoxicity
What class of antifungal is terbinafine and what is the MOA
Class: Allylamine
MOA: inhibits synthesis of ergosterol (main sterol in fungal cell membrane)
Terbinafine is fungiSTATIC/CIDAL
Fungicidal
Spectrum and side effects of terbinafine
Spectrum: Broad (aspergillosis, blastomycosis, cryptococcosis, histoplasmosis, coccidiomycosis, Malassezia)
SE: mile liver enzyme elevations, GI upset, facial dermatitis and pruritis in cats
What class of antifungal is caspofungin and what is its MOA
Class: Echinocandin
MOA: blocks synthesis of the cell wall by interrupting glucagon synth ease complex
Spectrum and side effects of caspofungin
Spectrum: disseminated Candida infections (fungicidal) and aspergillosis (fungistatic)
SE: fever, phlebitis, rash (histamine-release) and increased ALT
MOA of griseofulvin; cidal or static?
MOA: inhibits mitosis via disruption of the mitosis spindles causing mitosis arrest
Fungistatic
Spectrum and side effects of griseofulvin
Spectrum: limited to organisms causing dermatophytosis; NOT effective against yeasts
SE: vomiting, teratogenesis and anemia (at high doses in cats)
What is lufenuron and it’s MOA
Benzylphenol urea derived from insecticide used as an oral flea control; can be used as antifungal
MOA: interferes with chitin synthesis (in outer cell wall of fungi)
What is 5-flucytosine and MOA
Originally anti-cancer, can be used as antifungal but rapid resistance develops (especially for cryptococcosis and candidiasis)
MOA: interferes with RNA and DNA synthesis after conversion to 5-FU (prevents synthesis in fungal cell)
Fungistatic and time dependent
Spectrum: Limited (cryptococcosis, candidiasis, aspergillosis, sporotrichosis)
SE: BM suppression, GI upset
What classes of antiarrhythmics are used for tx of supraventricular tachycardia
Beta blockers
Calcium channel blockers
Digoxin
What classes of antiarrhythmics are used for tx of ventricular tachycardia
Acronym = SPAAM
Sotalol
Procainamide
Atenolol
Amiodarone
Mexiletine
What is used to treat bradyarrhythmias?
Pacemaker
MOA of pimobendan
Calcium sensitizer (acts on heart muscle) → positive inotrope
Phosphodiesterase-3 inhibitor arterial and venous vasodilation) – arterial vasodilation (decreasing after load) and venous vasodilation
Emodepside
- MOA
- Indications
- Cats/dogs?
- Adverse effects
- Anti-parasitic. Binds to latrophilin receptor presynaptically –> signal transmission cascade –> release of inhibitory neuropeptides into the synaptic gap –> induces inhibition & flaccid paralysis of the pharyngeal and somatic musculature of nematodes.
- Effective against GI nematodes. Used for resistant hookworm infestation. Combo with praziquantel expands spectrum of activity to include cestodes +/- trematodes.
- PO (dogs), topical (cats)
- SE: dogs - minimal. Cats - licking/excessive grooming, scratching treatment site, salivation, lethargy, alopecia, agitation. V+. D+, ocular irritation, respiratory irritation, shaking/tremors.
- HW testing before using drug, as can cause rapid death of microfiliaria –> fatal anaphylactic reaction.
Exenatide
- MOA
- Indications
- Cats/dogs?
- Adverse effects
- Glucagon-like peptide-1 (GLP-1) receptor agonist. GLP = incretin hormone, secreted by GIT in response to food intake.
- MOA: slow gastric emptying –> decrease post-prandial hyperglycemia; induce satiety. Roles in glucose homeostasis.
- Adjunctive tx of Type 2 DM with insulin & diet (cats). Intermediate (BID) & extended release (q7d) formulations.
Rabacfosadine
- MOA
- Indications
- Adverse effects
MOA:
* Nucleotide analog antineoplastic prodrug.
* Preferentially taken up by lymphoid cells & metabolized to 9-(2-phosphonylmethoxyethyl guanine) –> inhibits DNA synthesis/repair after being doubly phosphorylated.
Indications: canine LSA (conditionally licenced drug)
* Naive cases (multi-agent) & relapsed cases (single agent - 74% response rate).
* More effective in B-cell vs T-cell LSA.
* 1mg/kg IV q21d
AE: dose-dependent
* Dermatopathy - otitis externa or focal erythematous skin lesions on dorsum & inguinal regions
* GI
* Neutropenia (less common)
* Idiosyncratic pulmonary fibrosis (PF) - rare but life-threatening, usually develops late post-tx (median 4-5mths).
Metamizole
- MOA
- Indications
- Adverse effects
Analgesic without negative impact on mucosal perfusion.
Anti-pyretic & spasmolytic agent.
MOA: inhibits central COX-3 & activation of the opioidergic + cannabinoid systems.
Dipyridamole
- MOA
- Indications
- Adverse effects
CURATIVE consensus (2022 update)
- Similar to clopidogrel. Anti-platelet drug - inhibit ADP-induced platelet aggregation
- HWD (reduce embolic risk from dead worms)
Ticlopidine
- MOA
- Indications
- Adverse effects
CURATIVE consensus (2022 update)
- Anti-platelet drug. Thienopyridine. Irreversibly blocks the P2Y12 component of ADP receptor on surface of platelets –> without ADP, fibrinogen cannot bind to platelet surface & promote aggregation.
- HWD (reduce embolic risk from dead worms)
Prasugrel, cangrelor, ticagrelor
- MOA
- Indications
- Adverse effects
Anti-platelet drugs
P2Y12 receptor inhibitor
P2Y12 receptor: crucial role in ADP-mediated generation of thromboxane A2 (another important platelet activator). Signaling events downstream of the P2Y12 receptor also potentiate agonist-induced dense granule release and procoagulant activity.