Odema

Question 1

Water retention

Answer 1

Water retention in the system causing pulmonary(breathlessness) or peripheral oedema(swollen ankles and legs)

Question 2

Thiazides

Answer 2

bendroflumethazide and indapamide - BIT
- Long half life and given early in the day
- Inhibit sodium reabsorption at the beginning of the distal convoluted tubule
- Don’t want patient to be getting up in the night = more falls
- (Lasts up to 24hrs)
- If patient is prone to needed to go to the toilet in the night - give a loop diuretic

- Acts within 1-2 hours of oral admin and effects last 12-24hrs 
- Give in the morning to avoid diuresis at night which can interfere with sleep 
- Moderately potent 
- Indication - lower doses reduce blood pressure, with little biochemical disturbance 
- Higher doses are used for CHF, more effect on biochemical balance (potassium,sodium,Uric acid, glucose and lipids) - with little advantage on blood pressure 
- Bendroflumethazide- used for mild or moderate HF or hypertension(no longer 1st line)
- Chlortalidone - longer duration of action and may be given on alternate days Indapamide - lowers BP with less effects on electrolyte balance and less aggravation of diabetes

Question 3

Loop diuretic

Answer 3

only last 6 hrs, can be given twice daily without interfering with sleep
- Inhibits reabsorption from the ascending limb of the loop of Henle
- Used in pulmonary oedema due to left ventricular failure
- Furosemide,bumetanide and torasemide

Question 4

Loop diuretic

Answer 4

only last 6 hrs, can be given twice daily without interfering with sleep
- Inhibits reabsorption from the ascending limb of the loop of Henle
- Used in pulmonary oedema due to left ventricular failure
- Furosemide,bumetanide and torasemide

Question 5

Potassium sparring diuretics

Answer 5

• Amiloride, triamterene (blue pee)
  
  • Prevents sodium reabsorption in the distal tubule collecting duct
  Within potassium sparring, we have aldosterone antagonists- eg. Sprinalactone, eplerenone
  - If someone becomes dehydrated because of vomiting of diarrhoea - stop the aldosterone antagonist!!- until cleared up
  Potassium sparring - (letting it live) so increased potassium so don’t take with potassium so the other types can cause hypokalaemia

Question 6

ALL DIURETICS CAUSE:

Answer 6

ALL DIURETICS CAUSE: Hyponatraemia and hypomagnesaemia

- Loop and thiazide - hypokalaemia 
- Exacerbate diabetes and gout
- Hypotension

Question 7

Potassium sparring

Answer 7

• Hyper kalemia
  
  • Change in libido
  • Breast pain or tenderness

Question 8

Interactions - diuretics

Answer 8

Loop and thiazide = hypokalemia inducing drugs
Potassium sparring = hyper kalemia meds
Loop diuretics and aminoglycosides = nephrotoxicity and ototoxicity
Sprinlactone/loop + lithium = reduce lithium secretion - increase levels of lithium = toxicity

Question 9

Vascular disease:

Answer 9

• Occlusive peripheral vascular disease
  
  • Normally caused by atherosclerosis
  • Reduce risk with healthier life style, statins and anti platelets

Question 10

Vasospastic peripheral vascular disease - Raynaud’s syndrome

Answer 10

• Avoid exposure to cold and smoking cessation
  
  • If further treatment needed, nifedipine

Question 11

Thiazide diuretics:

Answer 11

• Work by inhibiting the reabsorption of sodium at the beginning of the distal convoluted tubule DCT by blocking the thiazide sensitive NACL symporter. Potassium is lost as a result of more reaching the collecting ducts - thiazide diuretics have a role in the treatment of heart failure,although loop are better for reducing overload.

Question 12

Loop diuretics (Bumetanide, Furosemide, and Torasemide)

Answer 12

Inhibit the sodium-potassium-chloride symporter
 Reduced sodium & chloride reabsorption and in turn inhibit magnesium
and calcium absorption, resulting in increased urinary output. Na, Cl, Mg, K
and Ca
Used in: pulmonary oedema due to left ventricular heart failure & relieve
breathlessness.
Can be used in antihypertensive treatment – loop diuretics are more effective in impaired renal function

Question 13

Loop diuresis within 6 hours:

Answer 13

can be given twice daily (last dose approx. 4pm)
Can exacerbate diabetes (hyperglycaemia) & gout
S/E: GI upset, pancreatitis, hepatic encephalopathy, altered-lipids
 Can cause urinary retention with enlarged prostates
 High doses of loop diuretics may lead to transient or permanent
deafness.
Heart failure- BD take last dose at 4pm.
- 20-40mg OM - furosemide dose

Question 14

Resistant hypertension:

Answer 14

• Bumetanide (most potent)
  
  • Torasemide(muscoskeletal pain)
  • Furosemide

Question 15

Thiazide diuretics:

Answer 15

Bendro, Chlortalidone, Indapamide, Metolazone
Inhibit sodium and chloride reabsorption at the distal convoluted tubule &
increase calcium reabsorption.
Chlortalidone and indapamide preferred in the management of hypertension
Duration of action 12-24 hour: give early in the day
Can exacerbate: Diabetes, gout and SLE
Monitor electrolytes, particularly at high doses.
Renal impairment: Ineffective is eGFR <30ml/in
Heart failure OM 5mg
Hypertension 2.5mg OM - bendroflumethazide doses

Question 16

Indapamide

Answer 16

(less diabetes)

Question 17

Metolazone

Answer 17

(use in less severe renal failure)

Question 18

Chlortalidone

Answer 18

long half life given on alternate days if a cute retention is a problem or dislikes frequent ruination

Question 19

Hypertension

Answer 19

Low dose produces near maximal effect, higher doses of little
advantage

Question 20

Thiazide diuretics SE

Answer 20

Side Effects: Postural hypotension, altered plasma lipids, electrolyte
disturbances, gout.
Potassium loss (hypokalaemia):
 Greater with thiazides than loops (T>L)
 Hypokalaemia is dangerous in CVD and those treated with digoxin
 In hepatic failure: Can precipitate encephalopathy, particularly in alcoholic
cirrhosis
Can also precipitate hypomagnesaemia in alcoholic cirrhosis
Amiloride and triamterene are weak diuretics that cause retention of potassium.
 Avoid potassium supplements, ACEi and A2RBs due to risk of hyperkalaemia.
 Triamterene may turn urine blue in some lights.
Diuretic Interactions (applies to brinzolamide and dorzolamide)
 ACE Inhibitors: Hypotensive effect
 Digoxin: Cardiac toxicity from hypokalaemia
 Lithium toxicity: Reduced secretion, increased plasma concentration.
 NSAIDs: Reduce efficacy of diuretics, risk of nephrotoxicity
 Aminoglycosides & Loops diuretics: Ototoxicity
NSAIDs & Diuretics:
Prostaglandins normally cause vasodilation of arterioles to the kidneys. Constriction causes hypertension and salt (fluid) restriction

Question 21

Diuretics

Answer 21

 Combination treatment may be apt in resistant oedema
 Vigorous diuresis may 🡹 risk of acute hypotension
 Gravitational oedema may be treated with movement alone
 Osmotic Diuretic i.e. IV mannitol may be used to treat cerebral odema
Carbonic Anhydrase inhibitors i.e. acetazolamide – weak diuretic for altitude
sickness prophylaxis

Question 22

Hypokalaemia

Answer 22

 Associated with loop and thiazide diuretics
 Risk depends on duration of action and potency (greater with thiazides)
 Dangerous in severe CVD disease, especially patients on cardiac glycosides
 Consider K+ sparing diuretic or K supplement
 Hypokalemia in heart failure can precipitate encephalopathy
 Increases risk of hypomagnamesia – 🡹 risk of arrythmia in alcoholic cirrhosis

Question 23

Thiazide Diuretics

Answer 23

 Inhibits the NaCl channel in the proximal segment of the distal convoluted
tubule
 Used to treat odema due to chronic heart failure
 Moderately potent
 Can exacerbate diabetes
 Not to be used to treat gestational diabetes
 Side Effects:
o GI disturbances
o Postural hypotension
o Hypokalemia (Avoid in refractory hypokalaemia)
Monitoring
 electrolytes
Preferably taken in the morning
1. Bendroflumethiazide (Centyl K, Low Cently K)
o Oedema: 5 -10 mg daily
o Hypertension: 2.5 mg daily
2. Chlortalidone (Atecor CT)
o Longer duration
3. Indapamide (Natrilix)
o Natrilix: one 2.5mg tablet in the morning
o Natrilix SR: one 1.5 mg tablet in the morning
 4. Metolazone

Question 24

Loop diuretics

Answer 24

 Inhibits reabsorption of sodium and chloride in the loop of Henle 🡹 increased
excretion of water and loss of calcium and magnesium ions
 Used to chronic heart failure, pulmonary odema due to left ventricular failure
 Can be combined with an antihypertensive for better BP control
 Hypovolemia and hypotension should be corrected before treatment
 Side Effects:
o GI upset
o Pancreatitis
o Hepatic encephalopathy
o Postural hypotension
1. Bumetanide (Burinex)
o Treatment of odema

Question 25

Loop diuretics - Acts within 1 hour

Answer 25

o Dose-related diuresis
o 1 mg in the morning
2. Furosemide (Lasix)
o Treatment of odema and resistant hypertension
o Acts within 1 hr
o Dose-related diuresis
o 20 – 40 mg daily. Max 120 mg daily (resistant odema)

Question 26

Potassium-sparing Diuretics

Answer 26

Promote urination(diuretics) without the loss of potassium by inhibiting the sodium changes in the distal consulates tubule. They are weak diuretics used as an adjunct ion to loop and thiazide diuretics

Question 27

Triamterene

Answer 27

Urine looks blue, - Used in preference over potassium supplements in counteracting hypokalaemia

Question 28

Side effects

Answer 28

Side effects:
- Hyperkalemia
- Avid ACEi/ARB,K+ supplements, aldosterone antagonists

Question 29

K+ Sparing diuretics are not

Answer 29

normally required in regular treatment of
hypertension
 K supplements must not be given with K+ sparing diuretics
 Many patients on diuretics do not need K+ supplements
 Co-treatment with ACEI or ARB 🡹 risk of hyperkalaemia
 Modified release k+ tablets should be swallowed whole with plenty of fluid
while sitting/ standing
 i.e. amiloride, triamterene – weak diuretics on their own. Usually used in
combination with thiazide or loop diuretics as a more effective alternative to
potassium supplements

Question 30

Amiloride

Answer 30

Amiloride + furosemide (Co-amilofruse – Frumil)
 Used to treat odema, hepatic cirrhosis with ascites
 Frumil 40mg/5mg Tablets
 Frumil Low Strength 20mg/2.5mg
 1-2 tablets in the morning
o Amiloride + hydrochlorothiazide (Co-amilozide)

Question 31

Aldosterone antagonists

Answer 31

inhibits aldosterone which causes sodium re absorption via NA+/k+/h+ co transporter. Less potassium and hydrogen ions are exchanged for sodium and therefore less lost to urine
- Eg. Sprinalactone (used in ascites)
- Eplererone

Question 32

Aldosterone antagonists side effects:

Answer 32

Side effects:
- Gynaecomastia(benign breast tumours),menstrual disturbance
- Hypertrichosis
- Change in libido
- Hyperkalaemia,hyperuraemia,hyponatraemia

Question 33

AA interactions

Answer 33

• Severe hyperkalaemia

Question 34

Osmotic diuretics

Answer 34

Inhibits sodium and water re absorption by increasing the similarity (solute concentration)of blood and renal filtrate. Osmotic diuretics act on the parts of the nephron that are water permeable, proximal convoluted tubule and descending limb of the loop of Henle

Mannitol- (pharmacological inert sugar)
Used:Cerebral Odema
- High intracranial pressure

Simple gravitational oedema in the elderly:
- Low dose diuretic - not for long term use
- Try alternatives first eg, stockings,raising legs and movement

Question 35

VASCULAR DISEASE:

Answer 35

Peripheral vascular disease (pvd)

Occlusive:
Eg, intermittent claudication caused by atherosclerosis
(Peripheral arterial disease)
- Aspirin 75mg daily and statins as secondary prevention of cardiovascular events

Vasospastic:
- Eg.Raynauds syndrome
- Stop smoking and avoid cold exposure
- Nifedipine - used to treat Raynauds syndrome