Sem 4 Week 3 Lecture 5

Front 1

Pharmaceutics

Back 1

-History
-Biochemistry(chemical structure,structure-activity r/ship,site of action)
-Formulation(prep,method of administration,additives,preservatives,stability,storage)
-

Front 2

Pharmacokinetics

Back 2

-dose and duration of action
-absorption
-distribution(Vd,t1/2)
-biotransformation(metabolism)
-elimination
-drug interactions

Front 3

Pharmacodynamics

Back 3

-Organ effects
-Side effects

Front 4

Chemical structure of morphine?

Back 4

-5 aromatic rings forming T-shaped molecule(basic aminosite is essential for opioid activity)

Front 5

Substitutions at the Amino site

Back 5

Profoundly alters activity.

Front 6

Morphine site of action ?

Back 6

Peripheral and central u opiate receptor agonist.

Front 7

Morphine is O2 sensitive

Back 7

And stored in brown glass and < 25 oC.( 2 year shelf life)

Front 8

Formulation?

Back 8

Morphine sulphate- oral and parenteral(im/iv/sc)

Front 9

Oral bioavailability of morphine?

Back 9

30 %

Front 10

Morphine SC or IM ?

Back 10

Well absorbed
-onset:15-30 min
-peak effect: 45-90 min
-duration : 3-4 hrs
-rate of absorption affected by blood flow to site of injection.

Front 11

Morphine rapidly accumulates in visceral organs and lungs

Back 11

True

Front 12

Morphine distribution?

Back 12

Highly ionized and poor lipid solubility- slow to cross bloodbrain barrier.

Front 13

Morphine protein binding ?

Back 13

35 %

Front 14

Morphine doesnt cross placenta.

Back 14

False

Front 15

Morphine Vd ?

Back 15

2.8 L/kg

Front 16

Morphine biotransformation ?

Back 16

-Mainly via hepatic biotransformation(high hepatosplancnic clearance)

Front 17

With an oral dose of morphine,

Back 17

2/3 eliminated and 1/3 effective

Front 18

Elimination of morphine ?

Back 18

Via bile in liver
-10 % unchanged via kidney

Front 19

Ppl with liver failure have

Back 19

Low metabolism of morphine.

Front 20

Clearance of morphine ?

Back 20

-14.7 L/kg

Front 21

T 1/2 of morphine ?

Back 21

3-5 kg

Front 22

When do you have longer clearances of morphine ?

Back 22

-Extremes of age,liver,disease,drugs like phenytoin.

Front 23

Dose range of Morphine ?

Back 23

Bolus : typical 0.1 mg/kg (im/sc) q3/24

Front 24

CNS effects of morphine ?

Back 24

-Analgesia
-Sedation
-Miosis
-Reduced respiratory drive
-Nausea(central chemoreceptor trigger zone,delays gastric emptying)
-addiction and tolerance

Front 25

CVS effects of morphine ?

Back 25

-Orthostatic hypotension
-Histamine release(venodilatation)
-Central sympathetic Inhibition
-Bradycardia(vagal stimulation)
-Reduced cintractility in very large doses.

Front 26

Respiratory effects of Morphine ?

Back 26

-Dose dependent depression
-Apnoea with large doses
-Obstructive sleep apnea more sensitive in elderly and neonates
-antitussives
-Decreases ciliary motion
-Precipitate bronchospasm from histamine release

Front 27

GIT effects of morphine?

Back 27

-Biliary and Sphincter of Oddi spasms
-Constipation

Front 28

Genitourinary effects of morphine?

Back 28

-Increases ureteric tone
-Increases risk of urinary retention

Front 29

Cutaneous effect of morphine?

Back 29

Dilatation & flare secondary to histamine release

Front 30

Placental effects of morphine?

Back 30

-Crosses placenta and neonatal addiction in drug taking mothers.

Front 31

Drug interaction with morphine?

Back 31

-Additive sedation to other sedative drugs including alcohol.
-MAOI

Front 32

u receptor antagonist ?

Back 32

Naloxone

Front 33

3 opiates ?

Back 33

-morphine
-pethidine
-fentanyl

Front 34

What would you give for mild pain ?

Back 34

-Paracetamol
-NSAIDS
-Cox 2 inhibitors

Front 35

Moderate pain ?

Back 35

-Codeine phosphate
-Tramadol
-Clonidine
-Oxycodone

Front 36

Severe pain?

Back 36

-Opioids
-Ketamine

Front 37

Paracetamol is safe unless overdose which is fatal

Back 37

True

Front 38

Paracetamol ?

Back 38

-adults 1g qid
-kids 10 mg/kg qid
-kids acute pain management dose pushed to 15-20 mg/kg qid

Front 39

It's better to stay on the conservative side with paracetamol and add other analgesics.

Back 39

True(eg NSAIS)

Front 40

Multimodal management of a strained ankle ?

Back 40

-Paracetamol 1g qid strict
-Tramadol 100 mg po qid
-NSAID 200 mg po bd

Front 41

TRAMADOL

Back 41

-Part u agonist and part NA uptake inhibitor
-Central and spinal actions
-Low addictive potential
-Little constipation
-Nausea esp. with motion
-Interaction with antidepressants--> serotonergic syndrome(shaking and feeling tremor)

Front 42

Celecoxib

Back 42

COX 2 inhibitors

Front 43

PCA

Back 43

Patient controlled analgesia

Front 44

IV peak effects for diff. opioids.

Back 44

-morphine: 1 hr
-Pethidine : 30 min
-Fentanyl : 10-15 min

Front 45

Opioids via IM or SC ?

Back 45

-Slower absorption and peak effect delayed
-Last longer(morphine 3-4 hrs and pethidine 2-3 hrs)

Front 46

Oral Opioids ?

Back 46

-Works well but LOW bioavailability
-Oral/parenteral for morphine-> 3:1

Front 47

Other routes for opioids ?

Back 47

-Transdermal
-Rectal
-Epidural
-Intraarticular

Front 48

Opiods infusion kinetics?

Back 48

Takes 3 t1/2 to reach steady state.

Front 49

To achieve analgesia quickly,you need to

Back 49

Give a bolus as well as increase infusion rate.

Front 50

When does opioids work best?

Back 50

When used in conjunction with other analgesics.

Front 51

Oral morphine dosage formula!!

Back 51

Ask for formula.

Front 52

Methadone

Back 52

Opioid replacement drugs

Front 53

Chronic pain management

Back 53

Opioids are last resort.
-multimodal analgesia
-Antidepressants
-Gabapentin for neuropathic pain

Front 54

Neuropathic pain

Back 54

Shooting/tingling nerves(bedsheet on legs cause tingling)