High risk drugs

Question 1

Loading Dose of amiodarone

Answer 1

200mg TDS for 7 days, then 200mg bd for 7 days

Question 2

Maintenance dose amiodarone

Answer 2

200mg

Question 3

Side effects of amiodarone

Answer 3

Bradycardia/blue
Interstitial lung disease
Thyroid
Corneal/cutaneous
Hepatic/hypotension

Question 4

Monitoring of amiodarone before

Answer 4

TFTs
Serum potassium
Chest xray

Question 5

Monitoring on amiodarone

Answer 5

LFTS
TFTs every 6 months
eCG
Symptoms can continue for several weeks after discontinuation

Question 6

Warfarin and amiodarone

Answer 6

Increased anticoagulant effect of warfarin

Question 7

Beta blockers and amiodarone

Answer 7

Increased risk of bradycardia, AV block and myocardial depression

Question 8

Amiodarone and lithium

Answer 8

Risk of ventricular arrhythmias

Question 9

Amiodarone and digoxin

Answer 9

Increased digoxin concentration

Question 10

Digoxin mechanism

Answer 10

cardiac glycoside

Increases myocardial contraction and reduces conductivity in AV node

Question 11

Optimum plasma concentration digoxin

Answer 11

1-2 mcg/L

1.5-3 indicates toxicity

Question 12

Digoxin monitoring

Answer 12

serum electrolytes esp potassium

renal function

Question 13

Toxicity of digoxin

Answer 13

Made worse by hypokalaemia

Managed by giving potassium sparing diuretic

Question 14

Digoxin side effects

Answer 14

Nausea and vomiting
Blurred or yellow vision
Confusion or delirium

Question 15

Digoxin and erythromycin

Answer 15

Increased digoxin concentration

Question 16

Digoxin and rifampicin

Answer 16

Reduced digoxin concentration

Question 17

Digoxin and St John’s Wort

Answer 17

Reduced digoxin concentration

Question 18

Digoxin and diuretics

Answer 18

Increased toxicity of digoxin if hypokalaemia occurs with loops and thiazides

Question 19

Digoxin and CCBs

Answer 19

Increased digoxin concentration

Question 20

Lithium serum concentration

Answer 20

0.4-1 mmol/L

Above 1.5mmol/L fatal/toxic

Question 21

Lithium toxicity

Answer 21

Levels
Increased urination
Tremor and thirst
Hair thinning and hypothyroidism
Interactions
Upset stomach
Muscle weakness
Skin effect - acne or psoriasis

Question 22

Lithium monitoring

Answer 22

Lithium conc every 3 months
U&Es and TFTs every 6-12 months
Maintain sodium concentrations

Question 23

Lithium counselling

Answer 23

Maintain adequate fluid intake

Avoid dietary changes with sodium

Question 24

Lithium and ACE inhibitors

Answer 24

Excretion of lithium reduced by ACE inhibitors – Risk of lithium toxicity

Question 25

Lithium and NSAIDS

Answer 25

Excretion of lithium reduced by NSAIDS – Risk of lithium toxicity

Question 26

Lithium and diuretics

Answer 26

Excretion of lithium reduced

Question 27

Toxic signs of methotrexate

Answer 27

Blood dyscraisas Liver toxicity Pulmonary toxicity

Question 28

Monitoring of methotrexate

Answer 28

LFTS | U&es before starting

Question 29

Dose of methotrexate

Answer 29

7.5mg once weekly | Max weekly dose of 20mg

Question 30

Methotrexate and NSAIDS

Answer 30

Monitor dose of methotrexate as dose can be increased | Avoid OTC preparations

Question 31

Methotrexate and folic acid

Answer 31

5mg folic acid to prevent methotrexate-induced mucositis or myelosuppression

Question 32

Side effects of methotrexate

Answer 32

GI bleeding and ulceration | Hepatotoxicity

Question 33

Indication of phenytoin

Answer 33

Epilepsy (all except absence) and neuropathic pain

Question 34

Phenytoin concentration

Answer 34

10-20mg/L | Small dose may increase plasma conc excessively

Question 35

Phenytoin monitoring

Answer 35

FBC and LFTs

Question 36

Phenytoin side effects

Answer 36

``` P450 interactions Hirsuitism Enlarged gums Nystagmus Yellow staining of skin Teratogenicity Osteomalacia interfere with B12 metabolism Neuropathies ```

Question 37

Phenytoin counselling

Answer 37

Blood dyscraisa Skin disorders Take with or after food

Question 38

Phenytoin and NSAIDS

Answer 38

Effect of phenytoin enhanced

Question 39

Phenytoin and wafarin

Answer 39

Accelerates metabolism of wafarin

Question 40

Phenytoin and cimetidine

Answer 40

Inhibits metabolism of phenytoin

Question 41

Phenytoin and fluoxetine

Answer 41

Increased concentration of phenytoin

Question 42

Phenytoin and st johns wort

Answer 42

Reduced plasma conc of phenytoin

Question 43

Phenytoin and NSAIDS

Answer 43

Effects enhanced by NSAIDS

Question 44

Plasma concentration of theophylline

Answer 44

10-20mg/L

Question 45

Theophylline side effects

Answer 45

``` Tremor Heart arrhythmias Electrolyte imbalance- hypokalaemia Oxidase inhibitor Pain in abdomen Heachaches, insomnia and seizures ```

Question 46

Theophylline monitoring

Answer 46

Plasma theophylline conc Lung function test serum potassium

Question 47

Theophylline and quinolones

Answer 47

Increased risk of convulsions

Question 48

Theophylline and St Johns wort

Answer 48

Plasma conc of theophylline reduced

Question 49

Theophylline and rifampicin

Answer 49

Plasma conc of theophylline reduced

Question 50

Theophylline and cimetidine

Answer 50

Plasma conc of theophylline increased

Question 51

Theophylline and fluconazole

Answer 51

Plasma conc of theophylline reduced

Question 52

Warfarin loading dose

Answer 52

10mg

Question 53

Warfarin side effects

Answer 53

``` Haemorrhage Rash Bruising Bleeding Alopecia Unexplained drop in haematocrit Skin necrosis Purple toes jaundice hepatic toxicity ```

Question 54

Warfarin counselling

Answer 54

Avoid dietary changes Same time each day Report bleeding etc

Question 55

Warfarin and NSAIDS

Answer 55

Enhanced anticoagulation

Question 56

Wafarin and fluconazole

Answer 56

Enhanced anticoagulation

Question 57

Wafarin and statins

Answer 57

Enhanced anticoagulation

Question 58

Wafarin and cipro/metronidazole/ clarithromycin

Answer 58

Enhanced anticoagulation

Question 59

Wafarin and griseofulvin

Answer 59

reduced anticoagulation

Question 60

warfarin and antiepileptic

Answer 60

reduced anticoagulation

Question 61

warfarin and alcohol

Answer 61

Dependent on consumption

Question 62

warfarin and cranberry juice

Answer 62

Enhanced anticoagulation

Question 63

wafarin and vitamin K

Answer 63

anticoagulant effect antagonised by vit k