Drugs affecting the kidney Flashcards
how do osmotic diuretics work?
what are they used for?
example:
- mannitol
high molecular weight compounds, increased osmotic gradient by increasing osmolality inside the nephron
water follows into the nephron via osmosis
used for:
- increased intra-ocular pressure
- cerebral oedema
how do carbonic anhydrase inhibitors work?
what are they used for?
what are the side effects?
example: acetalozamide
they block the enzyme carbonic anhydrase, this causes increased sodium bicarbonate secretion
used in:
- glaucoma
- acute mountain sickness
- urinary alkalinsation
side effects:
- hypercholaermic metabolic acidosis
how do loop diruetics work?
what are they used for?
what are the side effects?
example: furesomide
they work by blocking the Na/K/Cl triple transporter in the thick ascending loop of Henle
they have massive diuretic effects, if given IV can increase blood flow
used for:
- pulmonary oedema, due to left ventricular heart failure
side effects:
- metabolic alkalosis
- increased calcium excretion
- increased magnesium excretion
- gout
- hypovolemia
how do thiazide diruetics work?
what are they used for?
what are the side effects?
example: bendroflumethiazide
they work by blocking the Na/Cl transporter in distal convoluted tubule
used in:
- hypertension (because relax vascular SM)
- odema in coronary heart failure
side effects:
- metabolic alkalosis
- hyperglycaemia (because of Katp activation)
- hyperlipidaemia
- gout
- increase in calcium reabsorption
what can atenolol be used for?
what is it?
B1 selective adrenoreceptor antagonist
can be used to prevent renin secretion
give some names for ACE inhibitors
when are they most effective?
possible side effects?
what else can they be used for?
ramapril, enalapril (longer half life than other drugs) catopril
they prevent the conversion of angiotensin I –> angiotensinII by binding to the active site of the ACE enzyme
they’re most effective in hypertensive patients with high plasma renin levels
dry cough seen in 8% of patients, due to bradykinin stimulation of nerve endings on mucousa
can be used in:
- antihypertensive therapy
- heart failure
- MI with heart failure
what are the side effects of ACE inhibitors?
- dry cough seen in 8% of patients
- massive hypotension particularly with 1st dosage
- hyperkalemia
- renal impairment (particularly for patients dependant on angiotensin II to maintain their GFR through efferent constriction)
what is given in the case of dry coughs seen with ACE inhibitors?
Lorastan,
AT1 inhibitors
they blocks the action of angiotensin II at their AT1 receptor
how do inhibitors of renin work?
they bind to S3bp binding site of renin which is essential for its activity
renin converts angiotensin –> angiotensin I
a major unwanted side effect is diarrohea
example: aliskiren
what is the neurogenic cause of diabetes insipidius?
how can it be treated?
lack of ADH release from the posterior pituatory
ADH analogues can be used
felypressin
desmopressin
what is the nephrogenic cause of diabetes insipidius?
how can it be treated?
ADH production is normal, but no response to it
a problem with the V2 receptors
thiazides are used for treatment
when is felypressin used?
oesophageal varicose veins
selective V1 agonist
when is desmopressin used
selective V2 agonist
used to neurogenic diabetes insipidius (too weak to be used for vasoconstriction)
what is iodothalamic acid used for?
used as radio contrast, for X rays to show the urinary tract
given IV
uses organic acid transporters
how can we make urine more alkaline
when will this be important?
be using potassium citrate
dissociates into potassium and bicarbonate anion
used if want to excrete acidic compounds
