Most importante drugzz + factzz (B- topiczz 9-30) Flashcards
B9: NEOSTIGMINE (carbamate derivative)
GROUP: Carbamate derivative (indirect parasympathomimetic)
MOA: It is a reversible cholinesterase inhibitor. The drug inhibits acetylcholinesterase which is responsible for the degredation of acetylcholine. So, with acetylcholinesterase inhibited, more acetylcholine is present by interfering with the breakdown of acetylcholine, neostigmine indirectly stimulates both nicotinic and muscarinic receptors which are involved in muscle contraction.
PK: Metabolized by microsomal enzymes in liver, it does not cross BBB, has low oral absorption so it is given IV or IM, but also as eye drops.
SE: At higher doses, bradycardia and hypotension can occur
INDICATION: Myasthenia gravis and to induce emesis.
B9: PYRIDOSTIGMINE (carbamate derivative)
GROUP: Carbamate derivative (indirect parasympathomimetic)
MOA: It is a reversible cholinesterase inhibitor. The drug inhibits acetylcholinesterase which is responsible for the degredation of acetylcholine. So, with acetylcholinesterase inhibited, more acetylcholine is present by interfering with the breakdown of acetylcholine, neostigmine indirectly stimulates both nicotinic and muscarinic receptors which are involved in muscle contraction.
PK: Longer duration of action tha neostigmine, and lower risk of GI effects
SE: Rare, but increased GI motility, diarrhea, salivation, and bradychardia
INDICATION: Myasthenia gravis and to induce emesis
B9: ATROPINE (tropane alkaloid)
GROUP: Tropane alkaloid (parasympatholytic)
MOA: M-ACh antagonist. Interacts with muscarinic receptors of effector cells and, by occupying these sites, prevent ACh from binding to the receptor.
PK: Well absorbed, crosses BBB, distributed in tissues, metabolize in liver and excretion via urine. Narrow TI (be careful with dosaging)
SE: Excessive salivation and vomiting, increase in IOP, decrease tear production
INDICATION: Cyclopegia, causes mydriasis, synechiae, iritis (inflammation of vascular membrane of the eye)
CONTRAINDICATION: Patients with glaucoma or KCS (?)
DOSE:
Dog: IM, IV 0.02 mg/kg
(OP poisoning 0.2-0.5 mg/kg IV 1/4, SC 3/4)
B9: GLYCOPYRROLATE (m-ach antagonist)
GROUP: Quaternary ammonium compound (parasympatholytic)
MOA: Interacts with muscarinic receptors of effector cells and, by occupying these sites, prevent ACh from binding to the receptor.
PK: Longer duration of action than atropine, safer to use, excretion in urine (I think)
SE: Constipation, hypothermia, cough
INDICATION: Pre-medication (decrease salivation)
CONTRAINDICATION: Horses with colic
B9: TROPICAMIDE (m-ach antagonist)
GROUP: Atropine derivative (M-ach antagonist and parasympatholytic) and uterus relaxant
MOA: Non‐selectively blocking muscarinic receptors to cause mydriasis and cycloplegia
PK: Rapid onset, short duration of action.
SE: Confusion, tachycardia, unsteadiness
INDICATION: Used in eye examinations
B9: BUTIL-SCOPOLAMINE (m-ach antagonist)
GROUP: M- ACh antagonist (Parasympatholyitc)
MOA: Interacts with muscarinic receptors of effector cells and, by occupying these sites, prevent ACh from binding to the receptor.
PK: Short half-life.
SE: Increase in heart-rate
INDICATION: Antispasmodic - used in horses with colic
CONTRAINDICATION: Horses with ileus
B10: EPINEPHRINE (adrenaline)
GROUP: Adrenaline, (Non-specific sympathomimetics)
MOA: Involves triggering a physiological response when it binds with alpha and beta-adrenergic receptors
PK: ?
SE: ?
INDICATION: Asthma, haemorrhages, prolong action of local anaesthetics e.g. lidocaine, anaphylaxis
B10: DOPAMINE (non-specific sympathomimetic)
GROUP: Non-specific sympathomimetic
MOA: Dopamine produces positive chronotropic and inotropic effects on the myocardium, resulting in increased heart rate and cardiac contractility.
PK: Rapid absorption, excreted in urine, short half-life, it’s action depends on dose
SE: Ventricular arrythmia, tachycardia, angina
INDICATION: Low dose: Receptors in the kidney to enhance perfusion of the kidney, which is useful in babesiosis or ethylene glycol (antifreeze) poisoning, medium dose: Beta-1-receptors → tachycardia and an increase in the blood pressure.,
high dose: alpha-1-receptors. The pressor effect is when the alpha-1-receptors are stimulated and lead to a lowered perfusion of the kidney i.e. if the low dose is highered significantly, you can end up with the opposite effect.
B10: EPHEDRINE (alpha-1 agonist)
GROUP: Amine, alpha-1-agonist
MOA: Ephedrine activates adrenergic α (and β?) -receptors as well as inhibiting norepinephrine reuptake, and increasing the release of norepinephrine from vesicles in nerve cells.
PK: Given PO
SE: CNS effects
INDICATION: Isoflurane-induced hypotension and incontinence
B10: CLENBUTEROL (β-adrenoceptor agonist)
GROUP: Bronchodilator, β-adrenoceptor agonist and selective sympathomimetic
MOA: Agonism of the beta(2) receptor stimulates adenylyl cyclase activity which ultimately leads to downstream effects of smooth muscle relaxation in the bronchioles
PK: Given PO
SE: - Tachycardia, tremors and a decreased uterine contraction → decreased by inhalation
INDICATION: Used primarily for the treatment of recurrent airway obstruction (RAO) in horses, feline asthma bronchitis, broncho-pneumonia, tracheal hypoplasia, tracheal collapse
CONTRAINDICATIONS: Contraindicated in heart failure, arrhythmia and decreased mast cell degranulation
- Not used in racehorses (because it is a doping agent)
- Not used in food producing animals -> cause meat to have less fat content
NOTE: Longer-Acting β2-Specific Drug
B10: SALBUTAMOL (β-adrenoceptor agonist)
GROUP: Bronchodilator, β-adrenoceptor agonist and selective sympathomimetic
MOA: Agonism of the beta(2) receptor stimulates adenylyl cyclase activity which ultimately leads to downstream effects of smooth muscle relaxation in the bronchioles
PK: Given PO
SE: - Tachycardia, tremors and a decreased uterine contraction → decreased by inhalation
INDICATION: Used primarily for the treatment of recurrent airway obstruction (RAO) in horses, feline asthma bronchitis, broncho-pneumonia, tracheal hypoplasia, tracheal collapse
CONTRAINDICATIONS: Contraindicated in heart failure, arrhythmia and decreased mast cell degranulation
NOTE: It is a short-acting specific sympathomimetic
B10: TERBUTALIN (β-adrenoceptor agonist)
GROUP: Bronchodilator, β-adrenoceptor agonist and selective sympathomimetic
MOA: Agonism of the β2- receptor stimulates adenylyl cyclase activity which ultimately leads to downstream effects of smooth muscle relaxation in the bronchioles
PK: Can be given SC and IV
INDICATIONS:
- Horse RAO
- Feline asthma bronchitis
- Broncho-pneumonia
- Tracheal hypoplasia
- Tracheal collapse
CONTRAINDICATION: Should be used cautiously in animals with diabetes, high blood pressure, overactive thyroid gland (hyperthyroidism)
NOTES: Longer-Acting β2-Specific Drug.
Less specific though!
Given to dogs, cats and horses
B10: SALMETEROL (β-adrenoceptor agonist)
GROUP: Bronchodilator, β-adrenoceptor agonist and selective sympathomimetic
MOA: Agonism of the β(2) receptor stimulates adenylyl cyclase activity which ultimately leads to downstream effects of smooth muscle relaxation in the bronchioles
PK: Can be given SC and IV
INDICATIONS:
- Horse RAO
- Feline asthma bronchitis
- Broncho-pneumonia
- Tracheal hypoplasia
- Tracheal collapse
NOTE: Most specific and most expensive
B10: XYLAZINE (a2- agonist)
GROUP: a2-agonist
MOA: Presynaptic binding of α2-adrenergic receptors –> decreased release of norepinephrine
PK: Fast absorption, good distribution (crosses barriers, metabolize in liver, excretion in urine, works within few mins iv and 10-15 mins im
SE: Emetic in cats and some dogs, penile prolapse in horse
INDICATION: Provide sedation, chemical restraint, analgesia, used against hyperglycemia and glaucoma
CONTRAINDICATION: Boxers/rottweilers
DOSAGE: Dogs and cats:
IM, IV, SC; 1-4 mg/kg
Cattle:
IV, IM: 0.05- 1mg/kg
Horse:
0.5-1mg/kg
B10: DETOMIDINE (a2- agonist)
GROUP: a2 agonist
MOA: Presynaptic binding of α2-adrenergic receptors –> decreased release of norepinephrine
PK: Fast absorbtion, good distribution, iv: immediately, im: few mins, metabolize in liver, excretion in urine, high bioavailability in cattle (less in eq)
SE: Penile prolapse in eq, hypothermia, diuresis
INDICATION: Provide sedation, chemical restraint, analgesia, good premedication, used in hyperglycemia
IN COMBINATION: With thiopentone, ketamine or opioids
CONTRAINDICATION: Food producing animals
B10: DEXMEDETOMIDINE (a2- agonist)
GROUP: a2 agonist
MOA: Presynaptic binding of α2-adrenergic receptors –> decreased release of norepinephrine
PK: Fast absorbtion, good distribution, iv: immediately, im: few mins, metabolize in liver, excretion in urine
SE: Vomiting, thermoregulatory issues, constipation, bradychardia
INDICATION: Provide sedation, chemical restraint, analgesia, good premedication, used in hyperglycemia
IN COMBINATION: With thiopentone, ketamine or opioids
CONTRAINDICATION: Food producing animals
DOSE:
Dog: IM, IV 5-10 μg/kg (pre-anaesthesia)
IM, IV 10-20μg/kg (sedation + analgesia)
Cat: IM, IV 40 μg/kg (both doses)
B10: ATIPAMEZOLE (a2- antagonist)
GROUP: a2- antagonist
MOA: Competitively binding to the α2-adrenergic receptor (preventing activation)
PK: Highest preference for ɑ2- over ɑ1-receptors, rapid onset (im:10 mins), first-pass metabolism in liver, excretion in urine
SE: Vomiting, hypersalivation, diahrrea
INDICATIONS: Reverse effect of dexmedetomidine and other toxicities
CONTRAINDICATION: Ketamin-medetomidine
B10: PROPRANOLOL (β-antagonist)
GROUP: β-antagonist (non-selective)
MOA: Blocking β-receptors, causing vasoconstriction. Hypotensive → 1st generation, group II antiarrhythmics
PK: Well absorbed from GI tract, it is lipophilic, has large Vd, low bioavailability
SE: Cough, difficulty breathing (bronchoconstriction)
INDICATION: Decreases blood pressure
CONTRAINDICATION: Asthma patients
B10: METOPROLOL (β1 antagonist)
GROUP: Specific β-antagonist
MOA: Blocking β1 -receptors, causing vasoconstriction. Belongs to 2nd generation Group II antiarrhythmics.
PK: Local anaesthetic activity, large Vd, metabolize in liver, short half-life in small animals
SE: Bradychardia, dizziness
INDICATION: Slows down heart rate -> Hypotensive
B10: TIMOLOL (non-specific β-antagonist)
GROUP: Non-specific β-antagonist
MOA: Blocking β-receptors, causing vasoconstriction. Hypotensive → 1st generation Group II antiarrhythmics
PK: Applied topically,
SE: Bradycardia, cardiac arrhythmias, heart block (β1-adrenergic receptor blockade), and pulmonary effects such as exacerbation of asthma and bronchospasm (β2-adrenergic receptor blockade).
INDICATION: Used in glaucoma (opens Schlemm channel) decrease IOP. Given to dogs and cats.
CONTRAINDICATION: Should be avoided in patients with cardiac or pulmonary disease
B11: PHENOBARBITAL (barbiturate)
GROUP: Barbiturate
MOA: GABAa, decrease Ca2+ accumulation –> inhibits the release of stimulatory neurotransmitters
PK: Good oral absorption, slow onset, metabolized in liver
SE: Polyphagia, plyurea/polydipisia, pancreatitis, hepatotoxicity
INDICATION: Epilepsy in dogs (both long- and short term), membrane stabilization, pre-anaesthetic, given orally, used in agressive patients and against tetanus in eq
CONTRAINDICATION: Greyhounds and chronic liver disease.
DOSAGE:
Dog: PO: 1.5 -5 mg/kg BID
NOTE: It is the most important anti-epileptic
B11: POTASSIUM BROMIDE (anticonvulsant)
GROUP: Anticonvulsant
MOA: Involving chloride ion channels (idk?)
PK: Medium oral absorption, long half-life, excreted by kidneys
SE: Nausea and vomiting
INDICATION: Monotherapy and add-on treatment (w/ phenobarbital) for long-term epilepsy
CONTRAINDICATION: Status-epilepticus
B11: LEVETIRACETAM (anticonvulsant)
GROUP: Anticonvulsant
MOA: Used in combination with phenobarbital or potassium bromide (not used alone). It decreases the Ca2+ influx of neurons → no neurotransmitter released → no spasm
PK: Short half-life, excretion via kidneys
SE: Effecting kidneys (slightly hepatotoxic), sedation and ataxia.
INDICATION: In combination with Phenobarbital or Potassium bromide. If the phenobarbital or potassium bromide was not effective and the animal is still seizuring, we can combine them with this drug and it will be effective in 60% of cases. Can be used in both long-term control of epilepsi and in status epilepticus.
B11: IMEPITOIN (anticonvulsant)
GROUP: Anticonvulsant (long-term treatment of epilepsy)
MOA: Acting on GABAa (agonist)
PK: Reach plateau effect quickly, extremely active drug
SE: Polyphagia and minimal effects of sedation, polyurea/polydipsia
INDICATION: Used alone, and has 60-90% effectiveness in long-term epilepsy
NOTE: It is an expensive drug, therefore it is not used so frequently
B11: DIAZEPAM (anticonvulsant)
GROUP: Benzodiazepines
MOA: Activation of the benzodiazepine binding site on GABAA, which lead to hyperpolarization of the postsynaptic neuron producing decreased neuronal transmission
PK: Highly lipid soluble, good oral absorption, long onset of action IM but fast onset IV and PO or IN, can be given rectally, excretion via kidney, can be re-administrated
SE: Alone: Paradoxical excitement, agitation, vocalization, and dysphoria may be seen after IV or IM administration
INDICATIONS: Status epilepticus and appetite stimulant.
CONTRAINDICATION:
- Paradoxical reaction (cat, greyhound)
- Aminoglycosides (inhibition of respiration)
DOSAGE:
Ca: IV: 0.5-2 mg/kg
Fe: IV: 0.5-2 mg/kg
B11: MIDAZOLAM (anticonvulsant)
GROUP: Benzodiazepines
MOA: Amplify inhibitory effects of GABAA, nerve inhibtion by allowing Cl- into cell.
PK: Metabolized in liver, can be absorbed intranasally, no first pass effect, shorter and less sedation than diazepam. Water soluble, but becomes lipid soluble in the body
SE: Decrease respiratory rate, ataxia, weakness
INDICATIONS: Pre-anastethic (w/ ketamine), anti-epileptic (status epilepticus), muscle relaxant
CONTRAINDICATION: Food producing animals and new borns (high liver toxicity)
B11: PROPOFOL (anticonvulsant)
GROUP: Injectable anaesthetics/ anticonvulsants
MOA: Decreases the rate of GABA dissociation from its receptors thus increasing the opening of chloride channels
PK: Milky white emulsion, fast distribution, quick hepatic metabolism (can be used in liver failure patients), excretion in urine, given IV
SE: Cardiac, respiratory and renal impairment, negative inotropic effect–> hypotension, increased ocular pressure–> not good in glaucoma
INDICATION: Used in status - epilepticus seizures
DOSAGE:
Dog/ Cat:
- IV 6-8 mg/kg (without premedication)
- IV 3-4 mg/kg (with premedication)
B11: PENTOBARBITAL (barbiturate)
GROUP: Barbiturate
MOA: GABAa, decrease Ca2+ accumulation –> inhibits the release of stimulatory neurotransmitters
PK: Respiratory depression, re-distribution in fat and muscle, accumulation in fat, excreted in urine
SE: Respiratory and cardiovascular depression, tissue irritation, liver insufficiency
INDICATION: Epilepsy in dogs (long-acting)
CONTRAINDICATION: Greyhounds are oversensitive
B12: ACEPROMAZINE (phentothiazine)
GROUP: Phentothiazine
MOA: Sedation by inhibiting postsynaptic central dopaminergic receptors (alpha 1 receptor)
PK: Large Vd, slow elimination, metabolise in liver, excretion in urine, bioavailability: PO-20%
SE: Penile prolapse and hypertension in eq, third eyelid prolapse in ca and fe, constipation, and dry mouth, paradoxical reactions
INDICATION: Calming, sedation, muscle relaxation, premedication
DOSE:
Dog:
PO: 1-2 mg/kg
IM/IV: 0.2-0.3 mg/kg
Horse:
PO: 0.1-0.4 mg/kg
IM/IV: 0.03-0.1 mg/kg
B12: ALPRAZOLAM (benzodiazepine)
GROUP: Benzodiazepine
MOA: Amplify inhibitory effects of GABA, nerve inhibtion by allowing Cl- into cell.
PK: Metabolism in liver, more potent than diazepam
SE: Alone: Paradoxical excitement, agitation, vocalization, and dysphoria may be seen after IV or IM administration
INDICATION: Anxiety and panic attacks
B12: DIAZEPAM (benzodiazepines)
GROUP: Benzodiazepines
MOA: Activation of the benzodiazepine binding site on GABAA, which lead to hyperpolarization of the postsynaptic neuron producing decreased neuronal transmission
PK: Highly lipid soluble, good oral absorption, long onset of action IM but fast onset IV and PO, excretion via kidney
SE: Alone: Paradoxical excitement, agitation, vocalization, and dysphoria may be seen after IV or IM administration
INDICATIONS: Epilepsy, anaesthetic induction, muscle relaxants, appetite stimulant in cats, can be used in heart patients
IN COMBINATION: Ketamine and etomidate
CONTRAINDICATION:
- Paradoxical reaction (cat, greyhound)
- Aminoglycosides (inhibition of respiration)
DOSAGE:
Ca: IV: 0.5-2 mg/kg
Fe: IV: 0.5-2 mg/kg
B12: CLOMIPRAMINE (tricyclic antidepressant)
GROUP: Tricyclic antidepressant
MOA: Inhibit the Serotonin + NA reuptake → anticholinergic, antiadrenergic, and antihistamines.
PK: Good oral absorption, high albumin binding, long onset of action, metabolize in liver, excretion in urine
SE: - Sedation
- Lethargy
- Vomiting
- Antimuscarinic
- Change in Appetite
- Urinary Retention
INDICATION:
-Separation anxiety
-Feline urine spraying - Acral lick dermatitis
CONTRAINDICATION: Cardiovascular dysfunction, epilepsy
B12: FLUOXETINE (selective serotonin reuptake inhibitor)
GROUP: Selective serotonin reuptake inhibitor
MOA: Selective inhibition of serotonin reuptake
PK: Good oral absorption, bound to albumin, metabolize in liver, elimination half-life 7-9 days
SE: Occasional vomiting
INDICATION: Stereotypes, aggression, depression, feline urine spraying, separation anxiety
CONTRAINDICATION: Epilepsy and hepatic impairment
B12: MIRTAZAPINE (antidepressant)
GROUP: A2- antagonist and antidepressant
MOA: A2 and H1 antagonism
PK: Elimination half life 40hrs in dogs and 10hrs in cats, given PO
SE: Vocalization and increased restlessness
INDICATION: Antidepressant and anti-emetic agent and apetite stimulation in cats
B13: GUAIPHENESIN (muscle relaxant)
GROUP: Central muscle relaxant, (Glycerol guaiacolate, Guaiacolglycerol ether)
MOA: They have a relative specific depressant action on CNS, causing
decreased motor activity or paralysis of voluntary muscles without loss
of consciousness
PK: Fast onset and elimination of action, large distribution, crosses placenta barrier, excretion in urine, given as infusion
SE: Mild, slight decrease of arterial blood pressure, respiratory depression (in large doses) and haemolysis
INDICATION: Horses, cattle, sheep – to adjunct anaesthesia,
dogs – strychnine poisoning (in pass).
They are also used to control certain spasmodic and painful disorders
of skeletal (spinal) muscles
B13: PANCURONIUM (peripheral muscle relaxant)
GROUP: Aminosteroid, peripheral muscle relaxant
MOA: Mechanisms of action are competitive antagonists of NACh. The blockade starts when 70-80% of receptors are antagonised.
Complete block at 90%
Blocking agents not metabolised at neuromuscular junction
PK: Long duration of action, poor absorption from GIT, metabolized in liver, excreted in kidney,
SE: Cardiovascular effects and release of histamine
INDICATION: Muscle relaxation
CONTRAINDICATION: Duration of action increased in patients with renal and hepatic dysfunction.
B13: ATRACURIUM (Benzylisoquinoline)
GROUP: Benzylisoquinoline
(Nondepolarizing / Competitive NM Blocking Agent)
MOA: Mechanisms of action are competitive antagonists of NACh. The blockade starts when 70-80% of receptors are antagonised.
Complete block at 90%
Blocking agents not metabolised at neuromuscular junction
PK: Intermediate duration, metabolised in plasma (safe in liver and kidney disease), precipitated in alkaline PH
SE: Bradycardia
INDICATION: Muscle relaxation
B13: SUXAMETHONIUM (succinylcholine chloride)
GROUP: Succinylcholine chloride (Depolarizing NM blocking drug)
MOA: Stimulates the opening of the NACh receptor
Depolarisation of the cell membrane
Inactivation of voltage-gated Na channels → no further action potentials
PK: Rapid onset of action, short lasting block, can be given IM in emergency, terminated in liver
SE: Bradycardia, paralysis/weakness, hyperkalaemia, high IOP (dogs, cattle, sheep = sensitive, horses, pigs = less sensitive), increases blood pressure, anaphylaxis, malignant hyperthermia
INDICATION: Assist in intubation (?)
B13: XYLAZINE (a2- agonist)
GROUP: A2 agonist
MOA: Presynaptic binding of α2-adrenergic receptors –> decreased release of norepinephrine
PK: Fast absorption, good distribution (crosses barriers, metabolize in liver, excretion in urine, works within few mins iv and 10-15 mins im
SE: Emetic in cats and some dogs, penile prolapse in horse
INDICATION: Provide sedation, chemical restraint, analgesia, used against hyperglycemia and glaucoma
CONTRAINDICATION: Boxers/rottweilers
DOSAGE: Dogs and cats:
IM, IV, SC; 1-4 mg/kg
Cattle:
IV, IM: 0.05- 1mg/kg
Horse:
0.5-1mg/kg
B13: DETOMIDINE (a2- agonist)
GROUP: a2 agonist
MOA: Presynaptic binding of α2-adrenergic receptors –> decreased release of norepinephrine
PK: Fast absorbtion, good distribution, iv: immediately, im: few mins, metabolize in liver, excretion in urine, high bioavailability in catlle (less in eq)
SE: Penile prolapse in eq, hypothermia, diuresis
INDICATION: Provide sedation, chemical restraint, analgesia, good premedication, used in hyperglycemia
IN COMBINATION: With thiopentone, ketamine or opioids
CONTRAINDICATION: Food producing animals
B13: DEXMEDETOMIDINE (a2- agonist)
GROUP: a2 agonist
MOA: Presynaptic binding of α2-adrenergic receptors –> decreased release of norepinephrine
PK: Fast absorbtion, good distribution, iv: immediately, im: few mins, metabolize in liver, excretion in urine
SE: Vomiting, thermoregulatory issues, constipation, bradychardia
INDICATION: Provide sedation, chemical restraint, analgesia, good premedication, used in hyperglycemia
IN COMBINATION: With thiopentone, ketamine or opioids
CONTRAINDICATION: Food producing animals
DOSE:
Dog: IM, IV 5-10 μg/kg (pre-anaesthesia)
IM, IV 10-20μg/kg (sedation + analgesia)
Cat: IM, IV 40 μg/kg (both doses)
B13: DILTIAZEM (class IV antiarrythmic and vasodilator)
GROUP: (Vasodilator and class IV antiarrhythmic) and calcium channel blocker)
MOA: Increasing blood flow and variably decreasing the heart rate via strong depression of A-V node conduction. It is a negative inotrope
PK: Well absorbed from the GI
SE: Rare, but vomiting and anorexia have been observed in cats
INDICATION: Hypertension and angina
B13: PIMOBENDAN (VETMEDIN)
GROUP: Phosphidiesterase inhibitor
MOA: Inhibits the PDE3 enzyme in the heart muscle → accumulation of cAMP → increase in calcium concentration →
Positive inotropic effect
PK: Given orally, one hour before meals, as feeding decrease its absorption and causes vomiting
SE: Very rare, mainly GI related (vomiting and diahrrea)
INDICATION: - Prolong survival time in heart failure
- Supraventricular tachyarrhytmias
CONTRAINDICATION: Outflow obstruction (HCM, stenosis) i.e. must perform an ultrasound before administration
B14: OXYBUPROCAINE (ester)
GROUP: Esters (local anaesthetic)
MOA: Act by blocking conduction in nerve fibres → without loss of consciousness or a depressed activity of CNS
PK: Determine absorption: site of application, dose, vasoconstriction. Duration of action: until concentration falls below critical level due to absorption from site of application. Metabolism hydrolysed by plasma esterase and degraded by hepatic metabolism
SE: Allergy, asthmatic seizure, local irritation, confusion, tremor
INDICATION: Topical anaesthesia: Numbing the surface of the eye
B14: LIDOCAINE (amide)
GROUP: Amide
MOA: Block action potential generation by blocking Na+ channels.
Act in their cationic form (they must be weak bases), but they must reach their site of action by penetrating the nerve sheath and axonal membrane as unionised species.
PK: Rapid onset of action, moderate protein binding, low lipid solubility.
SE: Asthmatic seizure, local irritation, confusion, tremor, fall in blood pressure
INDICATION: Used to ease pain from skin irritation, rectal painful disease
B14: BUPIVACAINE (amide)
MOA: Block action potential generation by blocking Na+ channels.
Act in their cationic form (they must be weak bases), but they must reach their site of action by penetrating the nerve sheath and axonal membrane as unionised species.
PK: High potency, medium onset of action, long-acting, high protein binding, highly lipophilic.
SE: Asthmatic seizure, local irritation, confusion, tremor, fall in blood pressure
INDICATION: is frequently the drug of choice in situations that require use of a long-acting agent (surgery or labor)
B14: ROPIVACAINE (amide)
GROUP: Amide
MOA: Block action potential generation by blocking Na+ channels.
Act in their cationic form (they must be weak bases), but they must reach their site of action by penetrating the nerve sheath and axonal membrane as unionised species.
PK: Long-acting, almost as high efficacy and potency as bupivacaine, but is safer to use
SE: Spinal cord injury, local irritation, confusion, tremor, fall in blood pressure
INDICATION: Spinal block (epidural), surgery of perineal region, anal or peri-anal region, obstetric operations, urology
B15: LIDOCAINE (sodium channel blocker)
GROUP: Amide
MOA: Block action potential generation by blocking Na+ channels.
Act in their cationic form (they must be weak bases), but they must reach their site of action by penetrating the nerve sheath and axonal membrane as unionised species.
PK: Rapid onset of action, moderate protein binding, low lipid solubility, penetrates BBB. Advantage → no negative inotropic effect i.e. can be given in heart failure.
SE: CNS effects
(excitation, tremors and convulsion. This can be treated with diazepam)
INDICATION: Ventricular arrythmia
CONTRAINDICATION: Cats are sensitive, so use lower dosage!
NOTE: Potassium supplementation is necessary (hypokalemia)
B15: PROPRANOLOL (B- antagonist)
GROUP: 1st gen B- antagonist (non-selective), Beta blocker.
MOA: Blocking B- receptors, causing vasoconstriction. Hypotensive → 1st generation, group II antiarrhythmics
PK: Well absorbed from GI tract, it is lipophilic, has large Vd, low bioavailability
SE: Cough, difficulty breathing (bronchoconstriction)
INDICATION: Decreases blood pressure, stimulate the heart
CONTRAINDICATION: Asthma patients
B15: MEXILETINE (sodium channel blocker)
GROUP: Sodium channel blocker
MOA:
PK: High bioavailability,
SE: Rare(??)
INDICATION: It is used in cardiomyopathy as well as ventricular arrhythmia
It is combined with beta blockers frequently.
B15: METOPROLOL (B- antagonist)
GROUP: Specific B-antagonist (Beta blocker)
MOA: Blocking B1- receptors, causing vasoconstriction. Belongs to 2nd generation Group II antiarrhythmics.
PK: Local anaesthetic activity, large Vd, metabolize in liver, short half-life in small animals
SE: Bradychardia, dizziness
INDICATION: Slows down heart rate -> Hypotensive
B15: DILTIAZEM (class IV antiarrythmic and vasodilator)
GROUP: (Vasodilator and class IV antiarrhythmic) and calcium channel blocker)
MOA: Increasing blood flow and variably decreasing the heart rate via strong depression of A-V node conduction. It is a negative inotrope
PK: Well absorbed from the GI
SE: Rare, but vomiting and anorexia have been observed in cats
INDICATION: Hypertension and angina
B15: DIGOXIN (cardiotonic)
GROUP: Cardiotonic (from the digitalis lanata plant)
MOA: They inhibit the Na+/K+ ATPase enzyme which is responsible for Na+ efflux and K+ influx -> increased contractility of the heart ->
Positive inotropic effect
PK: - Positive inotropic effect → improves the renal blood flow → increases water and Na+ excretion, given orally, excretion via kidney
SE: Cardiac arrythmias and bradycardia, hypokalemia and extracardial signs are GI-signs like vomiting. It has a narrow therapeutic index
INDICATION: Prolong survival time in heart failure, supraventricular tachyarrhytmias (it increases contractility)
CONTRAINDICATION: Should not be given with NSAIDs, glucocorticoids or Furosemide as they will compete for the protein albumin and it should not be used in patients with renal failure
ANTIDOTE: Digibind
B16: MAGNESIUM SULFATE (osmotic laxative)
GROUP: Osmotic laxative
MOA: They absorb water from the environment of the GI tract and from the body system (water retention).
PK: Quick acting, given orally
SE: Dehydration
INDCATION: Against constipation
CONTRAINDICATION: They require rehydration via infusion before these are given
B16: LACTULOSE (sugar alcohol)
GROUP: Sugar alcohol (and very important laxative)
MOA: In the colon, this drug is activated and decomposed by the bacteria to form smaller chain acids e.g. lactic acid, acetic acid, propionic acid, butyric acid etc. These smaller chain acids are what are responsible for the action of absorbing water to cause osmotic diarrhoea.
PK: Bad penetration through membrane, given rectally or PO
SE: Convulsions
INDICATION: Hepatic encephalopathy and against constipation
B16: LIQUID PARAFFIN (coating agent)
GROUP: Coating agent
MOA: It is given orally to soften and cover the faeces to make it slippery
PK: Given PO, is very lipophilic
SE: Long-term use (more than 1 week) can cause vitamin deficiency, a small amount can also be absorbed to form irreversible granulomas in the intestinal wall and liver, leading to stomach pain in both animals and humans
INDICATION: Against constipation (It is given orally to soften and cover the faeces to make it slippery)
B16: ACTIVATED CHARCOAL (adsorbent)
GROUP: Adsorbent
MOA: It can bind the bacterial endo- and entero-toxins
PK: Very potent, used alone or in combination
SE:??
INDICATION: This is frequently used, especially in cases of poisoning where we have toxins in the body
B16: MONTMORILLONITE (magnesium-aluminium silicate)
GROUP: Magnesium-aluminium silicate (adsorbent)
MOA: Its property is that it can disinfect the GI tract i.e. it has an antimicrobial as well as an antidiarrhoeal effect.
PK: Can be used alone.
B16: BISMUTH SALTS (adstringents)
Group: Bismuth-subsalicylate (adstringents)
MOA: These also bind and precipitate the damaged proteins to form a layer to coat the GI tract where it was damaged i.e. they form a protective layer. Not only the damaged proteins but also the toxin proteins can be bound and coagulated i.e. they can also act on other types of diarrhoea as well.
PK: More potent than adsorbents, and can be used in combination with them
SE: Can make faeces black
INDICATION: These drugs cause vasoconstriction and decrease the secretion of the GI tract i.e. help with diarrhoea. They also have an anti-inflammatory effect
CONTRAINDICATION: Cats (they are sensitive to salicyclic acid)
