OPIOIDS Flashcards
Do opioids have anti-inflammatory effect?
No
What are the problems that can occur with opioids?
- Tolerance (There is a decreased level of response despite maintaining the same dose)
- Dependence (if you stop the drug you get a psychological response)
- Side-effects
- Risk of overdose
Opioid SEs
- Sedation (AVOID DRIVING)
- Nausea and vomiting
- Convulsions
- Respiratory depression
- Constipation
- Urinary retention!!
- Pupil constriction
- Suppression of cough
- CV effects (at high doses)
- Euphoric state
Dry mouth
Euphoria
Sedation
Itch
GI - CONSTIPATION
N+V
Eyes - pupils constriction
Resp depress
List the weak opioids
- Codeine
- Dihydrocodeine
- Meptazinol
Morphine
- Given every 4 hours (or every 12 or 24 hours if MR)
- Some brands e.g. MST Continus, Morphgesic SR, Sevredol, MXL, Zomorph,
Oramorph - For oral solution, anything above 13mg/5ml is considered as schedule 2 CD (and anything less is just POM)
Morphine - common SE
N+V
Hypotension
Diamorphine
- Causes less nausea and hypotension than morphine
- Because of its solubility, it allows effective doses to be injected in smaller volumes (its good for palliative care)
Buprenorphine
- Has both opioid agonist and antagonist properties
- Unlike other opioids, its effects are only partially reversed by naltrexone
Buprenorphine - duration of action
- Much longer duration of action than morphine
- Sublingually, it is active for up to 8 hours
- Can be used as maintenance therapy in the management of opioid dependence (e.g. addicts)
What are the counseling points for buprenorphine oral lyophilisates (e.g.
Espranor)?
- Placed on the tongue and allowed to dissolve
- Patients should be advised not to swallow for 2 minutes
- They should not consume food or drink for at least 5 minutes after administration
Espranor and bioavailability?
- Espranor does not have the same bioavailability as other buprenorphine preparations
- So becareful when switching to another preparation
What are the cautions for transdermal use of buprenorphine
patches which requires extra monitoring?
- Fever
AND - Application site exposed to heat
These two increase the risk of absorption (e.g. therefore side effects)
What are the counselling points for patients on
Buprenorphine
patches?
- Apply to dry, non-irritated, non-hairy skin on the upper torso/upper arm (depends on which preparation)
- Change patch every 72 hours or 96 hours or 7 days
- Do not put the patch on the same area, and avoid that area for however long the
manufacturer recommends e.g.
7 days or 3 weeks)
Fentanyl
- The main formulation is the patch which is changed every 72 hours
What is the side-effect of IV fentanyl?
Muscle rigidity
What are the counseling points for applying fentanyl patches?
- apply to dry, non-irritated, non-hairy skin on the upper arm or torso
- Put a new patch on a
different area (avoid using the same area for several days)
Are buprenorphine and fentanyl PATCHES suitable for acute pain?
- NO!
- Because the long time to reach the steady state prevents rapid titration of the dose
Oxycodone
- Similar side-effect and efficacy to morphine
- Given every 4-6 hours, but MR is given either every 12 hours or every 24 hours
Pethidine
- Produces a prompt but short-lasting effect
- It is less constipating than morphine
- Used for analgesia in labor
Pentazocine
- Agonist and antagonist properties
- Precipitates withdrawal symptoms
- By injection, it is more potent than dihydrocodeine and codeine
- Avoid after MI
Pentazocine - Injection SEs
- Hallucinations and thought disturbances may occur by injection
Tapentadol
- Opioid antagonist and
inhibits noradrenaline reuptake - N&V and constipation less likley to occur with tapentadol than with other strong opioid analgesics
Tramadol - Schedule
3
Tramadol MOA
- Opioid antagonist and enhances serotonergic and adrenergic pathways
Tramadol - SE
- Fewer typical side-effects (less respiratory depression, less constipation, and less addiction potential)
- Although psychiatric reactions have been reported
Codeine preps
- Available on its own or in combination with paracetamol or Ibuprofen
Codeine avoid
- Not to be used in children < 12
- Not to be used in 12-18 with breathing problems
- Caution in people who are ultra metabolisers (CYP2D6) = too much codeine converted into morphine which can lead to morphine toxicity
If co-codamol is prescribed and no strength is stated
then 8/500mg is to be dispensed
Dihydrocodeine
- Similiar to codeine
- Co-Drydramol is 10/500mg
Other strengths include - 20/500, 30/500.
- Dihydrocodeine is available on its own as 10,20 and 30mg
What are the cautions for use of opioids?
- Asthma
- Impaired respiratory function
(AVOID in COPD) - Obstructive bowel disorder
- Hypotension
What are the signs of opioid overdose?
- Coma
- Respiratory depression (slow and shallow breathing)
- Pinpoint pupils
How do you treat respiratory depression?
- Artificial ventilation
- Or reversed by Naloxone
What is the opioid antagonist called?
Naloxone
- Used to reverse overdose
Naltrexone
- Prevent relapse is substance misuse or alcohol
How do you treat opioid-induced constipation?
- Osmotic laxative + stimulant
- Avoid BFL
