TLD

Question 1

name the conventional thiazides

Answer 1

• bendroflumethiazide
• hydrochlorthiazide
• chlorothiazide

Question 2

name the TLD

Answer 2

• indapamide
• metolazone
• chlortalidone
• xipimide

Question 3

contraindications of TLDs

Answer 3

• refractory HYPOkalaemia
• HYPOnatraemia
• HYPERcalcaemia
• Addison’s
• sympatomtic HYPERuricaemia
• severe liver disease
• severe RI (CrCl <30)
• pregnancy

Question 4

why are TLDs contraindicated in pregnancy

Answer 4

risk of neonatal thrombocytopenia, bone marrow suppression, jaundice, electrolyte disturbances, hyperglycaemia, reduced parenteral perfusion

Question 5

which 3 conditions can TLD exacerbate and therefore its use is cautioned

Answer 5

SLE
diabetes
gout

Question 6

cautions for TLD

Answer 6

• elderly
• risk of exacerbation: diabetes, gout, SLE
• severe CVD, or being treated with cardiac glycosides
• mild to moderate HI

Question 7

Why are TLDs cautioned in pt with severe CVD or being treated with cardiac glycosides

Answer 7

danger posed by hypokalaemia

Question 8

adverse effects - electrolyte imbalances include the following…
when is it advisable to monitor

Answer 8

• hyperglycaemia
• hypokalaemia
• hyponatraemia
• hypomagnesemia
• hypercalcaemia
• monitor esp with high doses and long term use, and in people with RI

Question 9

adverse effects of TLDs include

Answer 9

• electrolyte imbalances
• hypochloraemia alkalosis
• mild GI disturbances
• altered plasma lipid conc
• cardiac arrhythmias
• dizziness and headache
• ED
• choroidal effusion, acute transient myopia, acute secondary CAG
• blood and lymphatic system disorders rarely occur

Question 10

dose of indapamide for hypertension

Answer 10

2.5mg OD in the morning
or 1.5mg daily using MR prep

Question 11

dose of xipimide for hypertension

Answer 11

20mg OD in morning

Question 12

dose of chlortalidone for hypertension

Answer 12

• starting: 25mg OD in morning
• increase up to 50mg daily if necessary

Question 13

dose of metolazone for hypertension

Answer 13

• starting: 5mg OD in moring
• maintenance: 5mg OD alternate days

Question 14

monitoring requirements for all TLDs

Answer 14

• electrolytes, esp if high dose or long term

Question 15

TLD are ineffective in CrCl

Answer 15

under 30

Question 16

interactions - drugs that concern blood pressure

Answer 16

• ARBs/ACEi: can cause rapid fall in BP in a pt who is volume depleted
• alpha blockers: enhanced hypotensive effect and increased risk of 1st dose hypotension
• TCAs: increased risk of postural hypotension

Question 17

Use of lithium and TLDs

Answer 17

risk of increased levels and toxicity
monitor levels regularly if used together

Question 18

TLDs and aminoglycosides

Answer 18

increased risk of ototoxicity

Question 19

What monitoring is recommended if a pt is on high dose diuretic and an ACE/ARB is to be started

Answer 19

• if dose of diuretic is >80mg furosemide or equivalent, ACEi/ARB should be initiated under close supervision, and in some cases diuretic dose may need to be reduced or discontinued at least 24h beforehand
• if high dose diuretic cannot be stopped, close observation is recommended for at least 2h following 1st dose of ACE/ARB, or until BP is stable

Question 20

concomitant use of TLDs and NSAIDs

Answer 20

increased risk of nephrotoxicity and antagonism of diuretic effect

Question 21

Use of CCs and TLDs

Answer 21

may potentiate hypokalaemia effect

Question 22

use of insulin and oral anti-diabetics with TLDs

Answer 22

may require dose adjustment

Question 23

Use of alprostadil, CCBs, BBs, hydralazine, nitrates, anxiolytics, MAOIs, methyldomia, minoxidil with TLDs

Answer 23

enhances hypotensive effect

Question 24

amiodarone, disopyramide, fleicanide and TLDs

Answer 24

hypokalaemia caused by TLDs increases risk of cardiac toxicity of these drugs

Question 25

use of allopurinol with TLDs

Answer 25

concurrent use may increase incidence of hypersensitivity reactions to allopurinol

Question 26

monitoring requirements of TLDs

Answer 26

serum electrolytes esp if long term use or high dose or RI

Question 27

can digoxin be used with TLDs

Answer 27

caution as predicted to increase risk of digoxin toxicity

Question 28

how potent are the TLDs as diuretics

Answer 28

moderately potent

Question 29

MOA of TLDs

Answer 29

inhibit sodium reabsorption at beginning of distal convoluted tubule

Question 30

how soon after oral administration to TLDs work and what is their duration of action

Answer 30

typically within 1-2h oral admin, duration of action 12-24h

Question 31

what time of the day to administer

Answer 31

usually in a.m. to not disturb sleep

Question 32

in the management of hypertension, what dose of TLD would you expect and why

Answer 32

- low dose TLD provides maximal or near maximal BP lowering effect with very little biochemical disturbance - higher doses cause more marked changes in plasma potassium, sodium, uric acid, glucose, lipids - with little or no advantage in BP control

Question 33

what are the 2 TLDs preferred in management of hypertension

Answer 33

chlortalidone and idapamide (bendro also licensed but not 1st line anymore)

Question 34

characteristics of chlortalidone - duration of action - use in oedema - useful in which pt? - other indication

Answer 34

- a TLD - longer duration of action than thiazides - can be given on alternate days to control oedema - useful if acute retention is likely to be precipitated by a more rapid diuresis or if pt dislikes the altered patter or micturition caused by other diuretics - can also be used under close supervision for treatment of ascites due to cirrhosis in stable pt

Question 35

characteristics of indapamide - related to - useful in which comorbid?

Answer 35

- chemically related to chlortalidone - indapamide claimed to to lower BP with less metabolic disturbance - less aggravation of DM - use this diuretic in pt with DM

Question 36

characteristics of metolozone - combination - side effect

Answer 36

- effective when combined with loop diuretic (even in renal failure) - profound diuresis can occur so monitor carefully

Question 37

which set of patients are particularly susceptible to adverse effects of TLDs?

Answer 37

elderly - caution

Question 38

why is regular monitoring of plasma sodium essential

Answer 38

fall in plasma sodium may be asymptomatic initially

Question 39

this thiazide has MHRA advice re the risk of non melanoma skin cancer, esp in long term use + advice to give

Answer 39

hydrochlorthiazide advice pt to check for and report any new or changed skin lesions or moles. limit exposure to sunlight and UV rays and use adequate sun protection. reconsider use of this in pt who have had PHx skin cancer. examine all suspicious moles or skin lesions.