Pharmacology cheat sheet Flashcards
pyrantel
cholinergic agonist that binds to nicotinic receptors to depolarize and act as a neuromuscular-blocking agent to paralyze susceptible parasites
small animals: rounds and hooks
horses: strongyles, pinworms, large rounds
fenbendazole
benzimidazole antiparasitic that disrupts intracellular mircotubular transport systems by binding tubulin, preventing tubulin polymerization, and inhibiting microtubule formation
broad dewormer: rounds, hooks, whips, tapes excluding Dipylididum caninum
ivermectin
avermectin antiparasitic
macrocyclic lactone binds glutamate-gated chloride ion channels within invertebrate nerve and muscle cells resulting in cell hyperpolarization causing paralysis. and death of the parasite
heartworm preventative and skin/ear mites in small animals
MDR1 (ABCB1) mutation causes CNS toxicity
DONT USE: chelonians, indigo snakes, crocodilians, skinks
praziquantel
anticestodal antiparasitic
causes irreversible focal vacuolization with subsequent cestodal disintegration at specific sites of the integument to cause susceptibility to digestion
used in horses, sheep, goats, camelids, birds, small mammals, reptiles
piperazine
thought to paralyze susceptible nematodes
primarily used for ascarids
limited efficacy, not usually used today
OTC
sulfa/trimethoprim sulfadiazine
potentiated sulfonamides
sulfa is bacteriostatic and when used with trimethoprim is bacteriocidal
good efficacy against many bacteria resistant to other common antibiotics
side effects: KCS, hematuria, hemolytic anemia, polyarthritis
used in small animals, horses, birds, ferrets, reptiles
milbemycin oxime
macrolide antiparasitic used as heartworm preventative, hookworm control and removal of adult roundworms and whipworms
extra label for skin mites
can cause CNS signs in MDR1 mutant species or overdose situations
used in dogs and cats
moxidectin
macrocyclic lactone antiparasitic
milbemycin-class antiparasitic used in small and large animals
safe for MDR1 mutants but may cause CNS toxicity, anaphylaxis, or immune-mediated reactions at higher doses or when given with vaccines
can be used in combo for broader spectrum treatment, used for roundworms and hookworms
selamectin
topical antiparasitic in small animals
potential MDR1 mutant breed concerns
combo products improve efficacy
labeled for fleas, heartworm, ear mites, scabies in dogs, and cat rounds and hooks
used in small animals and exotics
afoxolaner, sarolaner, fluralaner, lotilaner
isoxazoline ectoparasites
oral/topical flea/tick treatment and preventatives for dogs and cats
extra label: demodex, scabies, ear mites
starts killing fleas within 3 hours of administration, kills most ticks within 48 hours, and maintains for 30 days
caution in animals with history of seizures or overdose
imidacloprid
acts on nicotinic acetylcholine receptors on the post-synaptic membrane causing CNS impairment and death
OTC oral tablets, topicals, and collars
oral labeled for dog fleas only, starts killing within 1 hour
topically used on cats for long duration
fipronil
phenylpyrazole antiparasitic that interferes with the passage of chloride ions in GABA-regulated chloride channels in invertebrates disrupting CNS activity and causing death
labeled for flea, tick, and chewing lice
used in combo with Permethrins and Pyriproxyfen
nitenpyram
neonicotinoid insecticides
binds to nicotinic acetylcholine receptors in the postsynaptic membranes and blocks acetylcholine-mediated neuronal transmission causing paralysis and death of fleas
used in cats and dogs, extra label in reptiles
Rx and OTC
comboed with Lufenuron and Milbemycin
starts working in 30 minutes and can be repeated up to once daily
oral and rectal forms, or crushed in a wound for maggots
spinosad
oral macrocyclic lactone
contains spinosyn A and spinosyn D
nicotinic acetylcholine D-alpha receptor agonist causing involuntary muscle contractions and tremors secondary to motor neuron activation, prolonged exposure causes paralysis and death
starts working in 30 minutes
monthly dosing for dogs and cats
combined with milbemycin oxime for dogs
lufeneron
IGR-Chitin synthesis inhibitor
prevents flea eggs from hatching, doesn’t kill adults
combined with milbemycin oxime, praziquantel, and nitenpyram
permethrins/pyrethrins
OTC
permethrins are a synthetic pyrethyroid insecticide
very toxic to cats, don’t use on dogs that live with cats
signs of toxicity: hyperesthesia, generalized tremors, muscle fasciculation, hyperthermia, seizures
used in flea shampoos
IGRs
OTC often combined with permethrins and other OTC insecticides
aminoglycoside/aminocyclitol antibiotics
primarily used for gram negative aerobes
mostly topical formulations
oto and nephrotoxic
should only be used systemically when necessary with culture/sensitivity results with monitoring
quinolones
effective against a variety of pathogens except anaerobes
avoid use in young animals due to negative impact on cartilage development
higher doses (> 5mg/kg/day) of enrofloxacin can cause blindness in cats
caution in renal/hepatic insufficiency or. dehydration patients
pradofloxacin oral suspension approved for use in cats
cephalosporins
1st generation typically effective against most gram positive pathogens, variable coverage against gram negative pathogens but used for UTIs
2nd and 3rd generations retain gram positive pathogen activity with enhanced gram negative pathogen activity
often cause GI effects that can be minimized with some labeled once daily formulations
caution in renal insufficiency
macrolides
useful for treating a variety of bacterial, rickettsial, and protozoal infections
possesses a broad spectrum with in vitro activity against gram positive and greater gram negative activity
long tissue half-lives in dogs and cats
caution in hepatic dysfunction
aminopenicillins
time-dependent, bactericidal agent that acts by inhibiting cell wall synthesis
susceptible to inactivation by beta-lactamase-producing bacteria
neurotoxicity associated with high doses or prolonged use
potentiated aminopenicillins
sulbactam combined with aminopenicillins to enhance their spectrum to bacteria that produce beta-lactamases that would otherwise render them ineffective
good choice for beta-lactamase-producing gram positive aerobic and anaerobic bacteria
tetracyclines
many bacteria are resistant
doxycycline and minocycline are preferred due to more favorable dosing frequency and adverse effect profile
use with niacinamide to help control sterile inflammatory skin conditions in dogs
can cause staining of developing teeth and bones
lincosamides
broad-spectrum coverage against many anaerobes, gram positive aerobic cocci, and toxoplasma spp.
contraindicated in hindgut fermenters
caution in renal/hepatic dysfunction patients
follow dosing with water to prevent esophageal strictures after administration
metronidazole
good anaerobic activity
used for GI symptoms and to treat Giardia
high doses can cause neurological symptoms
very bitter tasting
chloramphenicol
broad spectrum antibiotic with good tissue penetration including the eye, CNS, and prostate
caution in preexisting hematologic disorder patients and hepatic failure patients
can cause aplastic anemia in humans
amphotericin B
antifungal
injectable systemic formulation used for serious mycotic infections
nephrotoxic
fluconazole
oral particularly used for CNS infections
long duration of treatment
caution in renal/hepatic dysfunction patients
itraconazole
used for systemic and cutaneous mycoses
caution in hepatic/renal impairment patients
terbinafine and miconazole
used in many OTC athletes foot cream, jock itch cream, or shampoos
famciclovir
rapidly converted to penciclovir which inhibits herpesvirus DNA polymerase and eventually inhibiting viral DNA synthesis
caution in patients with renal dysfunction
lysine/ L-lysince
amino acid that is believed to compete with arginine for incorporation into many herpes viruses
believed that arginine is required for producing infective viral particles and when lysine is incorporated the virus becomes less infective
oseltamivir
neuraminidase inhibitor that has been suggested as a treatment for canine parvovirus infections or other mixed bacterial/viral infections
lokivetmab
monoclonal antibody
neutralizes interleukin-31 that is produced by activated T helper cells in dogs with atopic dermatitis, binds to receptors in the spinal cord that send signals to the brain to stimulate peripheral nerves to cause pruritus
dogs only
frunevetmab
monoclonal antibody
felinized immunoglobin G that binds to nerve growth factor that is responsible for noxious stimuli that. produces peripheral sensitization, neurogenic inflammation, and increased perception of pain
cats only
bedinvetmab
monoclonal antibody
limited information on mechanism of action but should be similar to Frunevetmab
only for dogs
CPMA (canine parvovirus monoclonal antibody)
synthetic antibody that binds to canine parvovirus neutralizing it before it can enter the cell
maropitant
neurokinin-1 receptor antagonist that acts in the CNS by inhibiting the binding of substance P which is the key neurotransmitter involved in vomiting
contraindicated if GI obstruction is suspected
can cause prolongation of the QT interval because of cardiac potassium channel blockage
caution in hepatic dysfunction patients
stings when given SQ which can be minimized with refrigerated storage
meclizine and dimenhydrinate
antihistamines with sedative and antiemetic effects used for motion sickness and vestibular disease
metoclopramide
stimulates upper GI motility without stimulating gastric, pancreatic, or biliary secretions
contraindicated with GI hemorrhage, obstruction, and perforation
apomorphine
rapidly acting centrally mediated emetic used in dogs, ineffective in cats
compounded tablets can be crushed or mixed with saline for use as eye drops or whole tablets via subconjunctival route
contraindicated in species that cannot vomit
hydrogen peroxide
induces vomiting by gastric irritation, may require large volumes
recommend administering in bathtub or outside to minimize need for cleanup
xylazine
can be used for both cats and dogs to induce vomiting
rarely used in small animal medicine
sedative effects can be reversed with yohimbine
caution in patients with pre-existing cardiac dysfunction
antineoplastics
chemotherapy, often dosed in a mg/m2 instead of mg/kg
handle with caution, use appropriate PPE, and biohazard disposal
NSAIDs
exhibit analgesic, anti-inflammatory, and antipyretic effects by cyclooxygenase (COX) inhibition
caution in renal/hepatic dysfunction patients
GI related side effects
meloxicam
considered COX-2 preferential (not specific) because at higher doses its COX-2 specificity is diminished
firocoxib
predominantly inhibits COX-2 and spare COX-1 (maintain normal GI, platelet, and renal function)
carprofen
COX-2 inhibition specificity depends on species
COX-1 sparing considered better than older COX-2 sparing NSAIDs
grapiprant
prostaglandin E2 EP4-receptor antagonist
doesn’t inhibit COX
decreases inflammatory effects of PGE2 which lessens pain transmission at sensory neurons
not antipyretic
elevated ALP and ALT reported with use of drug
flunixin
potent inhibitor of COX used in large animal
caution in patients with pre-existing GI ulcers or renal/hepatic/hematological diseases
ketoprofen
non-selective inhibition of COX-1 and COX-2
labeled for large animal use but used extra-label in small animal and exotics
phenylbutazone
proposed mechanism of action is COX inhibition
used mostly in horses
additional pharmacologic actions include reduced renal blood flow, decreased glomerular filtration rate, decreased platelet aggregation, and gastric mucosal damage
diclofenac and fluriprofen
inhibit COX-1 and COX-2
used in ophthalmic formulations
azathioprine
purine-antagonist used for a variety of autoimmune conditions
adverse effect: myelosuppression
caution in patients with hepatic dysfunction
may take weeks of treatment before immunosuppression occurs
cyclosporine
calcineurin inhibitor that focuses on cell-mediated immune responses with some humoral immunosuppressive action, it binds to T cell cyclophilin and blocks calcineurin-mediated T-cell activation
used for dogs to control atopic dermatitis and for cats to control allergic dermatitis
extra-label for immune-mediated disorders in dogs and cats, and to prevent rejection of kidney transplant in cats
glucocorticoids
have effects on almost every cell type and system in mammals
contraindicated with any disease process where suppressing the immune system will allow condition to become worse
side effects: PUPD, polyphagia, panting
iatrogenic hyperadrenocorticism can occur from prolonged use
used for various conditions from allergic reactions to auto-immune diseases
oral and injectable
methylprednisolone or prednisOLONE used in cats due to their decreased ability to absorb or convert prednisone into prednisolone
phenobarbital
barbiturate that causes CNS depression
side effects: lethargy, ataxia, PUPD, polyphagia, hepatotoxicity
dose frequency: q12 hours, peaks between 4-8 hours
monitoring bloodwork is usually drawn 6-8 hours after giving, monitor liver enzymes
oral and injectable
C-IV controlled substance
bromides
primary or adjunctive therapy for seizures
long half life requires loading dose then transition to maintenance after monitoring indicated appropriate concentrations, monitoring bloodwork is not time specific due to long half life
very salty
toxic effects: profound sedation to stupor, ataxia, tremors, hindlimb paresis, CNS signs
benzodiazepines
depress CNS subcortical levels producing anxiolytic, sedative, skeletal muscle relaxation, and anticonvulsant effects
IV, rectal, intranasally for status epilepticus and cluster seizures
relatively short acting, usually followed by phenobarbital
C-IV controlled substances
levetiracetam
broad spectrum anticonvulsant that can be used as adjunct therapy for canine epilepsy or when phenobarbital or bromides are not tolerated
dogs may become refractory over time
may be used as a second-line option when phenobarbital doesn’t control seizure in cats
dosing frequency: q8 hours
pimobendan
inodilator with both positive inotropic and vasodilatory effects
decreases heart rate in animals with CHF, enhances cardiac contractility without an increase in myocardial oxygen consumption
antitussives
butorphanol has 15-20 times the oral antitussive effects of codeine or dextromethorphan
used mostly for analgesia or sedation
hydrocodone combinations
combined with homatropine to prevent abuse
exhibits characteristics of other opioid agonists yet it tends to have a slightly higher antitussive effect than codeine because of direct suppression of the cough reflex in the medullary cough center
SSRIs (selective serotonin reuptake inhibitors)
may take 3-4 weeks before efficacy is noted or may need to increase dose
adverse effects: anorexia, lethargy, GI effects, anxiety/restlessness, vocalization, seizures, aggression
tricyclic antidepressants
used for behavior disorders, neuropathic pain, and pruritus in small animals
may reduce seizure thresholds in epileptic animals
side effects: sedation, anticholinergic effects (risk for serotonin syndrome)
may take a few weeks to see effects and need to taper when discontinuing
baseline CBC, serum chemistries, urinalysis, and baseline thyroid testing prior to therapy, 1 month after starting therapy, and then yearly as well as baseline ECG due to possible widening of QRS complexes, prolonged PR intervals, and inverted/flattened T waves
Trazodone (SARI)
used for behavior disorders, phobia related anxiety, postoperative confinement, transport, or examination phobia
side effects: GI disturbances, ataxia, sedation, tachycardia, increased anxiety, behavior disinhibition, aggression, mydriasis
caution in patients with severe cardiac disease or hepatic or renal impairment
