Pain Drugs Flashcards
(24 cards)
What is the mechanism of action of diclofenac?
- reversible inhibition of COX-1 and COX-2 enzymes
- ⬇️ prostaglandin synthesis
What are the indications for diclofenac?
Inflammatory diseases Post-op pain Pain Pyrexia Acute gout
What are the contra-indications of diclofenac?
Aspirin/NSAID hypersensitivity
Severe heart failure
Caution in elderly patients
What are the side effects of diclofenac?
GI discomfort and disturbance
- decrease risk of GI irritation by taking with food
Bleeding/ulceration
Renal failure
What are the interactions of diclofenac?
ACE inhibitors: ⬆️ risk renal impairment
SSRIs: ⬆️ risk of bleeding
Beta blockers/calcium channel blockers: NSAIDs antagonise hypotensive effects
What class of drug is codeine?
Opiate
What is the mechanism of action of codeine?
Activates u opioid receptors in the brain and spinal cord to inhibit pain transmission and modify the central perception of pain
What are the indications for codeine?
Mild-moderate pain
Diarrhoea
Cough suppression
What are the contra-indications of codeine?
Acute respiratory distress syndrome
Paralytic ileus
Conditions associated with ⬆️ICP and head injury (it interferes with pupil response which is vital for neuro obs)
What are the side effects of codeine?
Nausea and vomiting
Constipation
Dry mouth
Biliary spasm
What are the interactions of codeine?
Alcohol: enhanced hypotensive/sedative effects
Metoclopramide: antagonises effect of metoclopramide on GI activity
Cimetidine: inhibits opioid metabolism
What class of drug is morphine?
Opiate
What is the mechanism of action of morphine?
Activates u opioid receptors in the brain and spinal cord to inhibit pain transmission and modify the central perception of pain
What are the indications of morphine?
Severe pain (MI, perioperative analgesia)
Acute pulmonary oedema due to heart failure
Intractable cough in palliative care
What are the contra-indications of morphine?
Severe respiratory disease (COPD) ⬆️ ICP and head injury Undiagnosed acute abdomen Acute alcohol intoxication Hepatic failure
What are the side effects of morphine?
Nausea, vomiting, constipation
Drowsiness
Dry mouth,
respiratory depression
Rare: dependence, hallucinations, difficulty with micturition, headache, palpitations
What are the interactions of morphine?
Hypnotics: enhances sedative effect
What class of drug is paracetamol?
Non-opioid analgesic and antipyretic
What is the mechanism of action of paracetamol?
Weak inhibitor of COX enzymes = ⬇️ prostaglandin and thromboxane synthesis
Tissue specificity for CNS giving antipyretic/analgesic effects with little anti-inflammatory action
What are the indications of paracetamol?
Mild- moderate pain
Pyrexia
What are the cautions with paracetamol?
Hepatic/renal impairment
chronic alcohol abuse
What are the side effects of paracetamol?
Rare: rash, blood dyscrasias
In overdose: hepatic necrosis, renal failure
What are the interactions of paracetamol?
Coumarins: ⬆️ anticoagulant effect
Carbamazepine: ⬆️ paracetamol metabolism
What class of drug is diclofenac?
NSAID
