Session 14 - Lecture 1 - Poisoning Flashcards
1 - Poisoning
- STOPP-START
Poisoning: review content we’ve already visited no new DDI or ADRs and how to manage
STOPP START – medical review on managing pts and px.
2 - Lecture outline
- Pharmacological toxicity
- Biochemical toxicity
- Some specific OD examples and management principles
• Polypharmacy in the elderly and medicine use review
STOPP-START and other tools
_Understand different types of poisoning and the potential harm to body systems. Appreciate the principles of managing drug overdose.
Recognise when tools such as STOPP-START may be appropriately used in refining medication in polypharmacy_
“Consider poisoning first, specific ways manage overdose particularly whether through pharmacological biochemical toxicity.
As I mentioned in Jan I mentioned a guy called Paracelsus who suggested everything is a poison but it’s just the dose which dictates whether something is going to be poisonous - “The dose makes the poison””
3 - Adverse drug reactions and drug toxicity
• We know that all drugs can cause adverse drug reactions – dose, person, disease related
• What is seen as a beneficial effect in one situation may be an undesirable side effect in another and vice versa
loperamide - antidiarrheal effects, constipation in pain management
chlorpromazine – antipsychotic sedative, use in motion sickness
• Side effects lead to successful drugs too
-context and condition being treated
• ADRs typical of drug being used at therapeutic doses (see PV and PG lecture)
• Drug toxicity more commonly associated with effects that occur at supra therapeutic doses
• Acceptability of risk of unwanted effects associated with severity of disease
“1. “The dose makes the poison” - person specific disease, disease specific
2. Thought about other drugs and USING their side effects – some of the mu opioid agonists loperamide, (brand name Imodium) – specifically used as an anti-diarrhoeal agent (intestinal mu opioid agonist). Side effects of opioids such as codeine, morphine administered for analgesic effects get constipation, so using those side effects sometimes can be useful. Sometimes codeine is used as an anti-diarrhoeal agent.
Chlorpromazine have these particular sedative effects in their actions – as Mrs Jenkins suggested they can be used for their side effect actions – anti-emetic properties - D2 antagonism.
3. Side effects identified early on in trials can also indicate a good drug, manipulate the uses of drugs – haven’t discussed particularly about Sildenafil (brand name Viagra) – but originally bc of HT and HF but one of the side effects – PDE5 inhibition which caused vasodilation in cavernosal vessels so for ED.
Another one more recently, a colleague developing anti-cancer chemo agents in a drug not particularly useful for cancer but actually turned out had good anti-shingles med, developed anti-viral – became successful and now they’ve all bought new houses and new cars lol.
4. So most ADRs - thought about the crude extracts, plant extracts as medicines as well – SJW OTC talked about a lot – been able to refine these crude extracts – digitalis (plant)– digoxin, now been synthesised from plant extract, so given as a pharmacological prep, particularly ADRs to do with what’s going on at therapeutic doses.
5. Drug toxicity more so to do with extremes – taken an overdose, inadvertently been given a large dose of a particular agent
6. Balance between acceptability of risk -may have situation where dealing with cancer/therapeutic agent – doses we’re giving to treat the cancer – see some pretty horrible side effects – give stuff to manage that situation – but may have NSAID and 1 in 5000 incidence has a side effect – much less often than in the chemotherapeutic situation but may be deemed unacceptable due to the risk/benefit compared to chemo when you don’t have many options – NSAID fairly severe ADR so it’s the balance about giving the agent for a particular reaction.”
4
4
5
5
6
6
7
7
8
8
9
9
10
10
11
11
12
12
13
13
14
14
15
15
