Top 100 drugs

Question 1

What is the treatment for paracetamol OD and how/how long is it given for?

Answer 1

N-acetylcysteine (NAC)

Given IV for 21 hours, 3 x bags

Question 2

How does NAC prevent liver damage?

Answer 2

Replenishes glutathione which detoxifies the harmful metabolite of paracetamol (NAPQI)

Question 3

What bloods should be done pre and post NAC? Which single test is the best indicator of ongoing liver injury and recovery of liver function?

Answer 3

INR, ALT and creatinine

INR is best indicator

Question 4

What are the features of an anaphylactoid reaction?

Answer 4

Rash, wheeze, tachycardia, nausea

Question 5

What is activated charcoal used for?

Answer 5

1. Reduced absorption of poisons (including some drugs in overdose) from the gut
2. In multiple doses to increase the elimination of certain poisons

Question 6

How does activated charcoal work?

Answer 6

Poisons are aDsorbed onto the charcoal which reduces their aBsorption into the circulation

Question 7

What substances will activated charcoal work well for?

Answer 7

Weakly ionic, hydrophobic substances e.g. benzodiazepines, methotrexate

Question 8

What dose of activated charcoal is used for poisoning and when should it be given?

Answer 8

50g in 250ml water, PO, given within 1 hour of ingestion.

Question 9

What are the side effects of activated charcoal?

Answer 9

Vomiting, black stools, intestinal obstruction, risk of aspiration (can cause pneumonitis, bronchospasm and airway obstruction).

Question 10

What is the MOA of ondansetron?

Answer 10

5-HT3 antagonist

Question 11

What is adenosine used for?

Answer 11

Supraventricular tachycardia

Question 12

What is the MOA of adenosine?

Answer 12

Adenosine is an agonist of adenosine receptors on cell surface which increased AV node refractoriness thus breaking the re-entry circuit, allowing normal depolarisations from SA node to resume control of HR.

It also blocks conduction to the ventricles which allows closer inspection of the atrial rhythm on ECG.

Question 13

What are the adverse affects of adenosine?

Answer 13

Bradycardia
Asystole
Sense of impending doom
Breathlessness

Question 14

In what patients should adenosine not be used/should be used with caution?

Answer 14

Those with:
Hypotension
Coronary ischaemia
Decompensated heart failure
Asthma (can induce bronchospasm)

Risk in those with:
COPD
Heart transplant

Question 15

What dose of adenosine is used and by what route?

Answer 15

6mg IV, can be followed by 12mg IV

Question 16

What monitoring is required when using adenosine?

Answer 16

Continuous cardiac rhythm strip

Question 17

What needs to be given after adenosine?

Answer 17

Saline flush 20mL

Question 18

What are the 3 common indications for adrenaline?

Answer 18

1. Cardiac arrest
2. Anaphylaxis
3. To induce local vasoconstriction e.g. to prolong local anaesthesia or control mucosal bleeding

Question 19

What is the MOA of adrenaline?

Answer 19

Potent agonist of alpha1/2 and beta1/2 adrenoreceptors.

Has sympathetic effects including vasoconstriction of vessels supplying skin/mucosa/abdominal viscera (a1), vasodilation of vessels supplying heart and muscles (B2), and increase in HR, force of contraction and myocardial excitability (B1)- REDISTRIBUTES BLOOD FLOW IN FAVOUR OF HEART IN CARDIAC ARREST!

Bronchodilation and suppression of inflammatory mediator release from mast cells (B2)- anaphylaxis.

Question 20

What are the adverse effects of adrenaline?

Answer 20

Hypertension
Anxiety
Tremor
Headache
Palpitations
Angina/MI/Arrythmias esp. in patients with existing heart disease.

Question 21

What dose of adrenaline is used for cardiac arrest and at what point?

Answer 21

1mg IV (10mL of 1:10,000) given immediately if non-shockable rhythm, or just after 3rd shock and repeated every 3-5 minutes if shockable rhythm.

Question 22

What is the dose of adrenaline given in anaphylaxis?

Answer 22

Adult- 500mcg IM (0.5ml of a 1:1000 solution)

Question 23

What are the side effects of 5 alpha reductase inhibitors?

Answer 23

Impotence
Reduced libido
Breast tenderness/gynaecomastia
Hair growth 
Breast Ca- finasteride

Question 24

Who should not take or handle 5 alpha reductase inhibitors and why?

Answer 24

Pregnant women- can cause abnormal development of external genitalia

Question 25

What is finasteride and what is it used to treat?

Answer 25

5 alpha reductase inhibitor

BPE

Question 26

What is the usual dose of finasteride?

Answer 26

5mg OD PO

Question 27

How long does it take for 5 alpha reductase inhibitors to work?

Answer 27

Up to 6 months

Question 28

What are the two indications for use of alpha blockers?

Answer 28

1) BPE- first line treatment

2) resistant hypertension- add on treatment

Question 29

What class of drugs are doxazosin, tamsulosin and alfuzosin?

Answer 29

Alpha blockers

Question 30

What is the MOA of alpha blockers?

Answer 30

Bind to alpha1 adrenoreceptors in blood vessels and urinary tract (esp. bladder neck and prostate). This causes vasodilation and fall in BP, and reduced resistance to bladder outflow.

Question 31

What are the adverse effects of alpha blockers?

Answer 31

Postural hypotension
Dizziness
Syncope

(especially with first dose!)

Question 32

Who should alpha blockers not be used in?

Answer 32

Those with known postural hypotension

Question 33

What is the usual dose of doxazosin and when is it taken?

Answer 33

1mg daily, taken at night, increased at 1-2 week intervals according to response

Question 34

What are acetylcholinesterase inhibitors used for?

Answer 34

Mild to moderate Alzheimer’s disease

Mild to moderate dementia in Parkinson’s disease (rivastigmine)

Question 35

What class of drugs are donepezil and rivastigmine?

Answer 35

Acetylcholinesterase inhibitors