Poisoning + STOPP START

Question 1

What is the therapeutic index of a drug?

Answer 1

The amount of drug needed to get from therapeutic response to toxic response) - the larger the therapeutic index, the greater dose it takes to cause an overdose.

Question 2

What are the side effects of an opioid overdose?

Answer 2

Respiratory depression.

Question 3

What is an effect of an overdose of statin?

Answer 3

Rhabdomyolysis

Question 4

What is the effect of too much B-blocker?

Answer 4

Bradycardia and myocardial depression.

Question 5

What is biochemical toxicity?

Answer 5

When a drug or active metabolite causes cell damage.

Question 6

How can the biological toxicity of cyclophosphamide be overcome?

Answer 6

By giving it with MESNA - contains a thin group that protects the bladder epithelium from the toxic metabolite of cyclophosphamide.

Question 7

What antidote is given for paracetamol toxicity and how does it work?

Answer 7

Acetylcysteine

Replenishes glutathione, which allows safe metabolism of NAPQI and prevents cell damage.

Question 8

Name 2 methods that can be used to prevent absorption of an overdose.

Answer 8

• gastric lovage (stomach pumping) - pumps toxic contents out
• activated charcoal - given as a suspension in water, needs to be given within 1 hour, irritates stomach lining and causes patient to bring stomach contents and overdose back up (not suitable for patients that are at risk of aspiration).

Question 9

What antidote is used for opioid overdose and how does it work?

Answer 9

Naloxone

Opioid receptor antagonist that can displace opioids and block receptors.

Question 10

What antidote can be given for 2nd or 3rd degree heart block caused by an overdose of beta blockers, and how does it work?

Answer 10

Atropine

Competitively inhibits ACh

Question 11

What antidote is given for cyanide poisoning and how does it work?

Answer 11

Cheating agents e.g. Sodium nitrate - complex with the poison, reducing amount of free drug.

Question 12

What is fomepizole used for and how does it work?

Answer 12

Alcohol overdose - inhibits alcohol dehydrogenase, preventing production of toxic metabolites.

Question 13

What antidote can be given for acid poisoning?

Answer 13

Sodium bicarbonate.

Question 14

Haemodialysis is useful for overdose of which types of drugs?

Answer 14

Drugs with a small Vd - as it is likely that most of it is in the plasma.

Question 15

What is STOPP?

Answer 15

Screening Tool for Older People’s Prescriptions

Question 16

What is START

Answer 16

Screening Tool to Alert to Right Treatment

Question 17

Who are STOPP and START used for?

Answer 17

Aimed at patients 65 years and older, aim is to highlight and prevent inappropriate prescribing by following a list of specific guidelines about when you should stop and start specific treatments.

Question 18

Which patients should be particularly targeted by START and STOPP?

Answer 18

• those taking lots of medications
• comorbidities
• time-limited medications
• high risk medications