Tdm Drugs

Question 1

Which foods interact with warfarin

Answer 1

Vitamin k- green tea, green vegetables
Pomegranate juice
Alcohol

Question 2

Patients on warfarin should report nose bleeds lasting longer than…

Answer 2

10 mins

Question 3

Inr target for warfarin

Answer 3

Normally 2-3.5

Question 4

Risks of warfarin

Answer 4

Calciphylaxis
Haemorrhage
Avoid 48 hours post partum
Wocbp- teratogenic

Question 5

Interaction of warfarin

Answer 5

Doacs to treat hepatitis C

Question 6

Monitor for warfarin

Answer 6

LFT FBC clotting screen before start

Question 7

Lithium target

Answer 7

0.4-1 mmol/L

Question 8

Monitoring for lithium

Answer 8

Serum conc
Renal function, electrolytes
ECG
Fbc
Tfts
Bmi

Question 9

If lithium serum function is over 2

Answer 9

Seizures, coma, renal failure, arrhythmia, bp changes, circulatory failure

Question 10

Monitor symptoms of lithium toxicity like

Answer 10

Gi visual and cns disturbance
Tremor, muscle weakness
Hypothyroidism, renal dysfunction, benign intracranial hypertensikn

Question 11

Important interactions of lithium

Answer 11

Antispychotics- increase EPS
Increased risk of toxicity- ACEi, ARB, loop diuretics, k sparing diuretics, nsaids, thiazide like diuretics, SSRI, metronidazole (hyperkalaemia)
Neurotoxicity- methyldopa, phenytpin, carbemazepine, diltiazem, verapamil

Question 12

Lithium when dispensing

Answer 12

Ensure same brand as normal
Adequate salt and water intake essential

Question 13

Dioxin target conc

Answer 13

1-2mcg/l

Question 14

Dioxin electrolyte imbalances

Answer 14

Decreases k
Decreases mg
Increases calcium

Question 15

Monitoring digoxin

Answer 15

Electrolytes
Renal function
Hr

Question 16

Amiodaeone with digixin

Answer 16

Decrease dioxin dose by half

Question 17

Which drugs increase digoxin levels

Answer 17

Diltiazem verapamil nifedipine
Quinine
Spironolactone

Question 18

Which drugs reduces conc of digoxin

Answer 18

St John’s wort

Question 19

Which drugs increase risk of digixin toxicity

Answer 19

Nephrotoxic drugs and those that cause hypokalamia

Question 20

Warnings of digoxin toxicity

Answer 20

Arrhythmia heart block ❤️
Neurological signs-weakness, lethargy, dizziness, headache, confusion, psychosis
Gi- anorexia, n&v , diargoea, abdo pain
Visual- blurred/ yellow vision

Question 21

Theophylline target levels

Answer 21

10-20 mg/L
Or 55-110mcmol/L

Question 22

theophylline toxicity looks like

Answer 22

Vomiting, throwing up blood, agitation, restlessness, dilated pupils, tachycardia, arrythmias hyperglycaemia, severe hypokalaemia, convulsions,

Question 23

Counselling for theophylline

Answer 23

Check with hcp before taking new medication
Inform gp if stop or start smoking
Maintain same brand

Question 24

What should you monitor with theophylline

Answer 24

Potassium levels
Plasma theophylline levels

Question 25

Interactions of theophylline

Answer 25

Hypokalaemia- beta 2 agonists, corticosteroids, diuretics Increased concentration- diltiazem, verapamil cimetidine, ciprofloxacin, estrogen, erythromycin Increased risk of convulsions with quinolones Reduced theophylline concs with carbazepine, phenytoin

Question 26

What do you monitor with methotrexate

Answer 26

Fbc Renal Liver

Question 27

Antidote to methotrexate

Answer 27

Folinic acid

Question 28

Methotrexate causes

Answer 28

Blood dyscrasias- bone marrow supression Gi toxicity- stomatitis Liver toxicity Pulmonary toxicity- pneumonitis, cough, sob Teratogenicity- contraception for 6 mo

Question 29

Interactions of methotrexate

Answer 29

Acitretin- hepatotoxicity Nsaids and penicillin reduce excretion of methotrexate Increased toxicity with doxycycline, tetracycline, cuprofloxacin, PPIs Trimethoprim- haematological toxicity

Question 30

Which otcs need to be avoided with methotrexate

Answer 30

Nsaids and aspirin

Question 31

Counselling points methotrexate

Answer 31

Photosensitivity Once a week, take folic acid a different day

Question 32

Target conc phenytoin

Answer 32

10-20mg/L

Question 33

What we monitoring for phenytoin

Answer 33

Serum conc Ecg and BP LFT FBC folate and vitamin d

Question 34

Phenytoin toxicity looks like

Answer 34

Rem of eyes, difficult balancing, slurred speech, hyperglycaemia, double vision, blurred vision, confusion

Question 35

Warnings for phenytoin

Answer 35

Skin disorders- rash, toxicity epidermal necrolysis Blood disorders- fever, sore throat, bruising Suicidal thoughts Low vitamin d

Question 36

Interactions of phenytoin

Answer 36

Increased levels- amiodarone , diltiazem, fluconazole, miconazole, trimethoprim, metronidazole, clarithromyxin, Reduced levels- rifampicin, St John's wort, theophylline, itraconazole, ciclosporin

Question 37

Ciclosporin councelling

Answer 37

- Maintain specific brand - avoid live vaccines - avoid UV - Avoid high k and grapefruit juice

Question 38

Monitoring for ciclosporin

Answer 38

Fbc Electrolytes- k, mg LFTs Renal Lipids Bp

Question 39

Toxicity types ciclosporin

Answer 39

Neurotoxicity- tremor, headache, encephalopathy, drowsy Blood toxicity- infection, sore throat, bleeding Liver toxicity Nephrotoxicity Tachycardia and hypertension

Question 40

Interactions with ciclosporin

Answer 40

Increased conc- grapefruit juice, antifungal, diltiazem, clarithromycin, erythromycin, Reduced conc- carbemazepine, orlistat, phenobarbital, phenytoin, rifampicin, St John's wort