Pharm II- Urinary Tract Drugs Flashcards
What type of acids & bases are actively secreted by the Proximal tubules?
weak acids & bases
Are drugs with a charge or without a charge reabsorbed by the kidneys?
Drugs without a charge are reabsorbed
Weak acids are more rapidly excreted in what type of urine?
Alkaline urine (like in herbivores)
Weak bases are more rapidly excreted in what type of urine?
Acidic urine (like in carnivores)
What drug competes with Pen for a cycle transporter & reduces the elimination rate (prolongs duration) of both drugs?
Probenicide
Which drug inhibits uric acid secretion?
Sulphinpyrazone
Passive reabsorption of a drug from the PCT depends on what 2 things?
pH of urine & pKa of the drug
Renal excretion of weak acids ____ in low urinary pH (acidic urine).
Decreases
Renal excretion of weak acids____ in high urinary pH (alkaline urine).
Increases
Renal excretion of weak bases ____ in low urinary pH. (acidic urine)
Increases
Renal excretion of weak bases ___ in high urinary pH (alkaline urine).
Decreases
An acidic drug will be ______ in carnivores?
NON ionized (can be reabsorbed & prolongs drug's effects)
A basic drug will be ____ in carnivores?
Ionized
is eliminated
An acidic drug will be _____ in herbivores?
Ionized
is eliminated
A basic drug will be ____ in herbivores?
NON-ionized
can be reabsorbed & prolongs drug’s effects
The half life of a basic drug is less in which type of animal?
Carnivores
The half life of an acidic drugs is less in which type of animals?
Herbivores
Herbivores have delayed elimination of drugs with a ____ pKa.
high pKa
Carnivores have a delayed elimination of drugs with a ____ pKa.
low pKa
What drug decreases reabsorption of Glucose, H2O & Amino Acids in the PCT?
Dopamine
What drug decreases the reabsorption of Na & Cl in the Ascending LoH?
Furosemide
What 2 drugs increases the reabsorption of H2O, Ca, Na & Cl in the DCT?
Antidiuretic Hormone
Aldosterone
What drug decreases the reabsorption of H2O, Ca, Na & Cl in the DCT?
Thiazide diurectics
Which 2 drugs decrease the reabsorption of H2O, Ca, Na & Cl in the Collecting Ducts?
Atrial Natriuretic Peptide (ANP)
Urodilation
Where is most H2O reabsorbed?
Descending LoH
Where in the kidneys is there variable permeability to H2O?
DCT & Collecting Ducts
Which part of the glomerulus filters molecules based on size, shape & charge?
basement membrane of glomerulus
Which part of the glomerulus may phagocytose macromolecules?
visceral epithelium of the glomerulus
The basement membrane & podocytes only allow what to pass? (2)
small molecules & H2O
Which cells relax or constrict & change the available filtration area?
Mesangial cells
What causes relaxation of the mesangial cells & enhances the available filtration area?
Atrial Natiuretic Peptide (ANP)
What causes contraction of the mesangial cells & decreases the available filtration area?
Sympathetic innervation
What causes constriction of the mesangial cells & decreases the available filtration area?
Angiotensin II
______ blockers are important in preventing proteinuria in Cats.
Angiotensin II blockers
Glomerular nephritis is a/an _______ dz.
Immune Mediated Dz caused by immunoglobulin complexes
What percentage of H2O is reabsorbed in the PCT?
60-70%
The epithelium in the PCT is _____.
“Leaky” = passive flow in either direction
Na enters the cell via what?
Na/H exchanger
Na leaves the cell and enters the interstitium via what?
Na/K ATPase Pump
What is responsible for the counter-current system of the kidney?
the LoH
How is the counter-current system established in the kidney?
Via H2O permeability in the Descending limb & Na permeability in the Ascending limb
Where does active transport of Na occur?
THICK Ascending LoH
Which cells are responsible for the secretion of H in the Collecting Ducts?
Intercalated cells
Where in the Collecting Ducts can transport of H2O & ions can be individually regulated by hormones?
Tight jxns in between cells
Sprionolactone is an Aldosterone _____. What is its effect?
Aldosterone receptor ANTagonist
Diuretic effect
Which 2 diuretics allow more Na to reach the Collecting Ducts?
Thiazide & Loop Diuretics
Which 3 drugs decrease Na reabsorption in the Collecting Ducts?
Amiloride
Triamterene
Spironolactone
Are there dissolution protocols available for Ca carbonate or Ca oxalate crystals/stones?
NO
Which type of crystals/stone can you dissolve w/ drugs?
Struvite crystals/stones
What is the primary mediator of benign prostatic hyperplasia in dogs?
overproduction of dihydrotestosterone (DTH)
How do you TX acute prostatisis?
W/ appropriate antibiotics
What are the causes of urinary incontinence in animals?
urge incontinence = Cystitis or bladder stones
Reactive/spastic bladder
Urethral sphincter incompetence in the bitch
Which nerve controls bladder contraction & opens the internal sphincter?
Pelvic nerve
Which nerve contracts the internal sphincter of the bladder & relaxes the detrusor mm of the bladder?
Hypogastric nerve
Which diuretics are the most powerful?
Loop Diuretics
What are the loop diuretics (3)?
Furosemide
Bumetanide
Torasemide
What is the MOA of Loop Diuretics?
Inhibits the Na/K/Cl carrier –> blocks the establishment of the chemical gradient
Which drugs have venodilator action through endothelin derived kinin (NO/PGI2)?
Loop Diuretics
Increased _____ conc. in the distal tubule results in increased loss of ____ & _____ ions.
Na
H, K
Loop diuretics cause increased secretion of what 2 ions?
Ca & Mg
Loop diuretics cause decreased secretion of what?
Uric Acid
D: of Loop Diuretics?
strongly PPP
Metabolism of Furosemide?
Glucuronidation in the liver
Metabolism of Bumetanide & Torasemide?
CYP450 pathways in the liver
What are the side effects of Loop Diuretics?
HYPOKALEMIA
Metabolic Alkalosis
How can one avoid hypovolemia & hypotension in patients receiving Loop Diuretics?
Make sure animal has enough water
Which diuretics act on the distal tubule?
Thiazide diuretics
MOA of thiazide diuretics?
Decrease active reabsorption of Na (& Cl) by binding to the CHLORIDE site of the Na/Cl symport system –> blocks active transport of Na & Cl
Thiazides increase the excretion of what 2 ions (driven by Na/K pump)?
H & K
Parathormone & Calcitriol increase what?
Ca reabsorption
What are the 2 thiazides used in Vet med?
Chlorothiazide
Hydrochlorothiazide
Is K loss significant with Thiazide diuretics?
yes
What are the diuretic effects of thiazides?
moderate
Thiazides decrease the excretion of what 2 things?
Uric acid & Ca
Thiazides increase the excretion of what 2 ions?
Mg & Na
What are the extra renal actions of thiazides?
- Vasodilation
- Hyperglycemia (possible)
- Decreased blood volume (result of direct action)
- reduce bone loss in humans
What effect do thiazides have in Diabetes insipidus?
reduce the volume of urine