Nervous System

Question 1

What is the order of the pain ladder?

Answer 1

1) Non-opioids - Paracetamol & NSAIDs
2) Weak opioids - Codeine & tramadol
3) Strong opioids - Morphine, oxycodone, methadone
4) Very strong opioids - Fentanyl, Dihydrocodeine

Question 2

What is the MOA of weak opioids?

Answer 2

Codeine & Tramadol

• Weak µ-receptor agonist
• Tramadol also acts as a SNRI using the serotonergic and adrenergic pathways

Question 3

Side effects of weak opioids?

Answer 3

• Constipation
• Urinary retention
• drowsiness
• neurological and respiratory distress (overdose)

Question 4

Warnings of weak opioids?

Answer 4

• Tramadol reduces the seizure threshold - also increased risk of serotonin syndrome
• Epilepsy
• Renal & hepatic impairment
• Elderly
• Codeine and dihydrocodeine can never be given IV - increases risk of anaphylaxis like reaction

Question 5

What are some interactions of opioids

Answer 5

• Other sedating drugs e.g antipsychotics, benzodiazepines, tricyclic antidepressants

Question 6

What is a specific interaction of tramadol?

Answer 6

• Drugs that also reduce the seizure threshold e.g antipsychotics
• Serotonergic drugs e.g - SSRI and tricyclic antidepressant

Question 7

What commutation should you give a patient taking a weak opioid?

Answer 7

• May cause constipation - take a stimulant laxative (senna)

- Do not drive or operate heavy machinery

Question 8

What is the treatment pathway for epilepsy?

Answer 8

1) Carbamazepine
2) Valporate, lamotrigine e.t.c
3) Gabapentin, pregabalin e.t.c

Question 9

What drug can be used to treat serotonin syndrome?

Answer 9

1) Cyproheptadine - It is a serotonin antagonist

2) Benzodiazepines - muscle relaxants