Opioids other was corticosteriods Flashcards Preview

Clinical Pharmacology, Therapeutics & Principles of Prescribing > Opioids other was corticosteriods > Flashcards

Flashcards in Opioids other was corticosteriods Deck (19)
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1
Q

What is pain?

A
2
Q

What is the gate theory

A
3
Q

Draw a diagram show pain control

A
4
Q

Give examples of endogenous opioids

A
5
Q

Give examples of opiod receptors

state what receptor they are

MOA

A

µ mu (MOP) δ delta (DOP) κ kappa (KOP)

Mu sounds like muke which sounds like nuke has a K so K+ efflux

Kappa sounds like CAppa

Delta CAMP

6
Q

Draw a diagram showing how this results in reduced neurotransmitter release from the presynaptic neurone

A
7
Q

Adverse Drug Reactions? (Variable with each patient)

most ADRs are due to?

A

Vomit shortly after - direct stimulation to vomiting centre in the brain

constipation - Nerve plexus inhibited

drowsiness - sedatives/narcosis, induce sleep, problem with work
Smooth muscle relaxants?

hypo - Smooth muscle relaxants?

8
Q

Pharmacodynamics

Agonist e.g.

Partial agonist e.g.

Mixed agonist/antagonist e.g.

Full antagonist e.g.

A
9
Q

Describe the pharmacokinetics for morphine, diamorphine, methadone, buprenorphine

A
10
Q

Morphine structure, metabolism, location of action

A
  • multi ring
  • Amine group - interacts with binding pocket in opioid receptors
  • Hydroxyl molecules at 3 and 6 position - relatively polar groups and makes it more water soluble

Metabolism:

glucuronidation —> Morphine - 6 - glucuronide / Morphine - 3 - glucuronide

(Mu opiod receptor & extends half life)

Metabolites can be measured in urine – screening

11
Q

What is the half life of diamorphine? And how is it converted into morphine?

A
12
Q

Clinical Uses of Opioid Drugs

A

Main indication (analgesia) - relief of moderate to severe pain (particularly of visceral origin)

Morphine -analgesic (terminal illness), diarrhoea

Diamorphine - analgesic (terminal illness)Doesn’t matter as they will die soon if they develop dependency, epidural analgesia (not licensed)

Methadone - maintenance in dependence

Tramadol - analgesic (5-HT & NA effects)Opioid drug used in Leicester - on immune effector, prevents reputable of 5HT & noradrenaline from synaptic clefts (euphoric effects)

RAISES MOOD

Tapentadol - analgesic (specific μ agonist, and NA reuptake inhibitor)

13
Q

Clinical Uses of Opioid Drugs

State a mild analgesic

A

Codeine - mild analgesic (oral) (metabolised to morphine)

14
Q

Why might patients not get pain relief from codeine?

A
15
Q

Clinical Uses of Opioid Drugs

A

Fentanyl - Anaesthetics

Alfentanil - anaesthetic (ADR: can cause histamine release + morphine ADR)

Remifentanil - anaesthetic (ADR: can cause histamine release + morphine ADR)

100x more potent than morphine
Alfentanil + remifentanil 1000x
But very short half life

Pethidine - analgesia in labour (im) (ADR: resp d & norpethidine (metabolite) -> convulsions)
Do not give frequent repeat doses -> Accumulate in brain and CSF where it will remain active

16
Q

Opioid agonists-antagonists

  1. Give examples
  2. MOA Of nalbuphine
A

Pentazocine - analgesic

Nalbuphine -

Butorphanol -

Buprenorphine - “ Meptazinol -

  1. antagonist at µ, partial agonist at κ, weak agonist at δ
17
Q

Opioid Antagonists examples

A

Naltrexone derivative of naloxone -> longer half life -> Use: heroin & alcohol addiction

Effects in CNS manly in supraspinatous region - especially in respiratory centres

Indication: patients with opioid overdose and respiratory depression

MOA: two proved stack

Binds to the pockets of receptor to prevent other drugs from bind. INVERSE AGONIST removes any drug that is already bound to the receptor. Rapid onset 3/5 mins and can last as long as an hr.

18
Q

State the New Endogenous Receptor and Opioid Peptides that bind to it & MOA

A

Nociceptin opioid peptide receptor with ligand being nocipeptide

Related to kappa receptor

19
Q

Medico-legal Aspects

Some opioid analgesics are controlled drugs!

The Misuse of Drugs Act 1971

Misuse of Drugs Regulations 2001

Schedule 2: (controlled drugs)

Schedule 5: (controlled drugs)

A