UTI drugs info

Question 1

dose of nitrofurantoin for lower UTI for pregnant women - MR and IR preps

& when to avoid in pregnancy

Answer 1

100mg BD 7 days (MR prep)
50mg QDS 7 days (IR prep)

avoid at term risk of neonatal haemolysis*

Question 2

dose of nitrofurantoin for lower UTI for men - MR and IR preps

Answer 2

100mg BD for 7 days - MR
50mg QDS for 7 days - IR

Question 3

dose of nitrofurantoin for non-pregnant women with lower UTI - MR and IR preps

Answer 3

50mg QDS for 3 days - IR
100mg BD for 3 days - MR

Question 4

dose of nitrofurantoin for catheter associated UTIs (IR and MR)

Answer 4

50mg QDS 7 days (IR)
100mg BD 7 days (MR)

Question 5

when would you give immediate release preps over MR preps of nitrofurantoin for UTIs

Answer 5

when MR preps are unavailable

Question 6

nitrofurantoin dose for SEVERE CHRONIC RECURRENT UTI

Answer 6

100mg QDS for 3-7 days (using IR preps, not MR)

Question 7

dose of nitrofurantoin for prophylaxis of recurrent UTI (using IR preps)

Answer 7

50-100mg OD, at night
alternatively 100mg for 1 dose to be taken following exposure to trigger

Question 8

MHRA nitrofurantoin: pulmonary and hepatic adverse drug reactions

Answer 8

• increase vigilance for acute pulmonary reactions in 1st week of treatment
• closely monitor pt on long term therapy for new or worsening respiratory symptoms esp in elderly
• discontinue immediately if new or worsening symptoms of pulmonary damage
• caution when prescribing to pt with pulmonary disease which may mask signs and symptoms of adverse reactions
• be vigilant for signs and symptoms of hepatic dysfunction esp with long term therapy
• caution in pt with HI

Question 9

nitrofurantoin contraindicated in this age

Answer 9

under 3 months

Question 10

3 contraindications of nitrofurantoin

Answer 10

acute porphyrias
G6PD deficiency
less than 3 months

Question 11

what is the interaction (not severe or anything) between nitrofurantoin and vincristine and similar drugs

Answer 11

increased risk of peripheral neuropathy

Question 12

side effects which warrant discontinuation of nitrofurantoin (3)

Answer 12

• unexplained haematological or neurological syndromes (such as peripheral neuropathy) occur
• hepatitis
• pulmonary reactions (usually occur within first week of treatment and are reversible with cessation of therapy)

Question 13

acute pulmonary reactions with nitrofurantoin usually occur within …

Answer 13

first week of treatment

Question 14

can you use nitrofurantoin in BF?

Answer 14

avoid
only small amounts present in milk but enough to produce haemolysis in G6PD deficient infants

Question 15

giving nitrofurantoin to pt with renal impairment increases risk of

Answer 15

peripheral neuropathy

Question 16

avoid nitrofurantoin if eGFR

Answer 16

less than 45

Question 17

monitoring requirements of nitrofurantoin

Answer 17

• on long term therapy, monitor LFTs and monitor for pulmonary symptoms esp in elderly (discontinue if deterioration in lung function)

Question 18

patient and carer advice for nitrofurantoin - seek immediate medical attention if

Answer 18

signs of pulmonary, hepatic, haematological or neurological adverse reactions develop

Question 19

does nitrofurantoin effect driving and skilled tasks

Answer 19

yes
Patients and carers should be counselled on the effects on driving and performance of skilled tasks—increased risk of dizziness and drowsiness.

Question 20

do you need to take nitrofurantoin with or without food

Answer 20

take with or just after food or a meal

Question 21

nitrofurantoin can colour urine which colour

Answer 21

yellow brown

Question 22

use of trimethoprim in pregnancy and BF

Answer 22

• avoid in pregnancy, teratogenic risk in 1st trimester. folate antagonist.
• short term use in BF not known to be harmful

Question 23

trimethoprim dose adjustments in RI

Answer 23

• caution in RI
• dose reduction to half normal dose after 3 days if eGFR 15-30
• dose reduction to half normal dose if eGFR less than 15

Question 24

dose of trimethoprim for prophylaxis of recurrent UTI

Answer 24

100mg OD, at night
alternatively 200mg 1 dose to be taken following exposure to trigger

Question 25

dose of trimethoprim for catheter associated UTI

Answer 25

200mg BD for 7 days (14 days if upper UTI symptoms e.g. fever and loin pain are present)

Question 26

dose of trimethoprim for lower UTI for female (obvs not pregnant because avoid in pregnancy)

Answer 26

200mg BD for 3 days

Question 27

dose of trimethoprim for lower UTI for male

Answer 27

200mg BD for 7 days

Question 28

contraindication for trimethoprim (1)

Answer 28

blood dyscrasia

Question 29

interactions trimethoprim - MTX

Answer 29

avoid
increased risk of haematological SE (sometimes fatal)

Question 30

interactions trimethoprim - warfarin

Answer 30

increase AC effect of warfarin

Question 31

interactions digoxin and trimethoprim

Answer 31

T increases conc of digoxin
monitor digoxin conc

Question 32

trimethoprim is …. toxic

Answer 32

nephrotoxic so increased risk of nephrotoxicity with other drugs e.g. antivirals, aspirin, amphotericin B, cephalosporins, Cs, NSAIDs, lithium, MTX , ACEi etc

Question 33

trimethoprim interaction with ACEi and NSAIDs (2)

Answer 33

increased risk of nephrotoxicity
increased risk of HYPERkalaemia (esp notable with ACE or ARB given with spironolactone or eplerenone)
NSAIDs also increase risk of hyperkalameia as above

Question 34

can you take clozapine with trimethoprim

Answer 34

no avoid as increased risk of neutropenia

Question 35

monitoring requirements of trimethoprim

Answer 35

• blood counts with long term use and in those with or at risk of folate deficiency
• serum electrolytes in pt at risk of developing hyperkalaemia (e.g. ACE/ARB/NSAIDs/SEAT) and consider monitoring in other pt esp with long term use
• renal function esp with long term use

Question 36

trimethoprim can cause the following electrolyte imbalance esp if given with SEAT, ACE, ARB, NSAIDs

Answer 36

hyperkalaemia

Question 37

on long term treatment pt and their carers should be told how to recognise signs of blood disorders and are advised to seek immediate medical attention if symptoms e.g.

Answer 37

fever, sore throat, rash, mouth ulcers, purpura, bruising or bleeding develop.

Question 38

choice of abx therapy for UTI in pregnancy
1st and 2nd line

Answer 38

Oral first line: Nitrofurantoin.
Oral second line (if no improvement after at least 48 hours, or first line not suitable):
Amoxicillin (only if culture susceptible), or cefalexin

Question 39

prophylaxis of recurrent UTI - cefalexin dose

Answer 39

125mg OD, at ngiht
alternatively 500mg for one dose following exposure to a trigger

Question 40

dose of cefalexin for lower UTI + in pregnancy

Answer 40

500mg BD for 3 days
pregnancy: 500mg BD for 7 days

Question 41

cefalexin is ….toxic so….

Answer 41

nephrotoxic so combination with other nephrotoxic drugs (e.g. vancomycin, ACE, NSAIDs, antivirals, etc) increases risk

Question 42

are blood disorders common SE of cefalexin

Answer 42

yes, all cephalosporins

Question 43

what is methanamine hippurate and how does it work

Answer 43

urinary antiseptic agent
prevents urine infections as it has an antiseptic effect on urinary system
sterilises urine, stopping growth of certain bacteria

Question 44

what is methanamine indicated for

Answer 44

prophylaxis and long term treatment of chronic or recurrent uncomplicated lower UTIs (+ in pt with catheters)

Question 45

methanamine dose for prophylaxis and long term treatment of chronic or recurrent uncomplicated lower UTIs (+ in pt with catheters)

Answer 45

without catheter: 1g every 12 hours
with catheter: 1g every 8-12 hours