Pharmacology & Prescribing - Mod 5

Front 1

A woman is prescribed 75mg pethidine IV stat for pain reliefduring labour. The ampoules contain 100mg/2mL. What volume(ml) of pethidine solution are you going to giveher?

Back 1

1.5 ml

Front 2

What are the 3 main actions of NSAIDS

Back 2

anti-inflammatory

anti-pyretic

analgesic

Front 3

Why should NSAIDs not be used inpregnancy?

Back 3

NSAIDs easily cross the placenta and have an extended half life inthe fetus. Their use should be avoided during pregnancy, particularlyduring the 3rd trimester.

May cause closure of ductus arteriosus. Sometimes is usedtherapeutically post partum if ductus arteriosus has failed to closewith delivery.

Front 4

Why should NSAIDs be used with caution (if at all) in asthma

Back 4

May cause bronchoconstriction

Front 5

Select the true statements:

i) Dicolfenac binds to cyclooxyrgenase

ii) Dicolfenac interferes with the production of prostaglandins

iii) Diclofenac is metabolised in the liver

iv) Dicolfenac is an analgesic, anti-pyretic and anti-inflammatory drug

Back 5

All statements are true dicolfenac binds to cyclooxyrgenase, interferes with the production of prostaglandins, is metabolised in the liver, and is an analgesic, anti-pyretic and anti-inflammatory drug

Front 6

Name 3 conditions for which a midwife would prescribe paracetamol

Back 6

Pain

Fever

Mastitis

Front 7

Nitrous oxide is generally considered safe in labour althoughthere is a small risk of one serious side effect. What is the side affect?

Back 7

Megaloblastic anaemia

Front 8

Side effects of pethidine may include all except: a) Dysphoriab) Urinary retentionc) Seizuresd) Paralysis

Back 8

D) paralysis

Front 9

Outline why giving a woman pethidine for pain reliefin labour could affect the breathing of the newborninfant.

Back 9

Pethidine crosses the placenta and is not cleared bythe placenta at the same rate as it is in maternalcirculation. It is a respiratory depressant and could depressinfant respiration postpartum if given close to delivery.

Front 10

Outline the mechanism of action of a pharmacologicalintervention used to treat inadequate respiration innewborn infants following opiate administration to theirmother prior to their birth.

Back 10

Naloxone administration to the infant. It binds competitively to the same mu and kappa receptors preventing the action of the narcotic and reversing its effect. Has a shorter half life than the narcotic so re- administration may be necessary

Front 11

Describe a situation when you as a midwifewould prescribe lignocaine (local anaesthetic).

Back 11

Episiotomy

Repair of perineum

Front 12

What is another situation where local anesthetic may be used?

Back 12

Epidural (local anesthetic injected into epidural space)

Front 13

What is the mechanism of action of local anesthetics?Why may a person still feel mechanical activity in ananesthetized area, but not pain?

Back 13

Local anesthetic block voltage gated sodium channels. This means that electrical signals in the form of an action potentials cannot be propagated along an axon. Smaller diameter axons are affected before larger diameter axons which means that even though a person may not be able to feel pain sensation in an anesthetized area, they may still be able to feel touch, particularly deep touch. The person may require reassurance that this is OK and normal, and that the anesthetic is working.

Front 14

Lignocaine works by blocking:

a) voltage gated chloride channels

b) voltage gated sodium channels

c) calcium channels

d) potassium ion channels

Back 14

b) lignocaine works by blocking voltage gated sodium channels

Front 15

What types of medicines are most commonlyused for epidural anaesthesia?

Back 15

• Local anaesthetics (e.g. Bupivacaine)

• Opioids (e.g. Fentanyl)

Front 16

True or false? A withdrawal syndrome will occur following a single dose offentanyl.

Back 16

False.

A withdrawal syndrome (or abstinence syndrome) will occur if fentanyl (or another opioid) is stopped abruptly following chronic use.

Front 17

True or false? A withdrawal syndrome will be more likely if you prescribe a high dose of fentanyl.

Back 17

False.

As a midwife may only prescribe opioids intrapartum, the short-term nature of the opioid’s use means that neither a low dose nor a high dose will result in a withdrawal syndrome.

Front 18

True or false? Constipation, dizziness, sedation, nausea, vomiting and euphoria are common opioid side-effects.

Back 18

True.

Front 19

True or false? Pethidine is more potent that morphine.

Back 19

False.

Morphine is approximately TEN times more potent that pethidine. You need to give 100mg of pethidine to get the same analgesic effect as 10mg morphine.

Front 20

True or false? Due to the delayed and variable onset and efficacy, oral opioids are not appropriate for intrapartum analgesia.

Back 20

True.

Front 21

True or false? Acute respiratory depression and paralytic ileus are contraindications to opioid use.

Back 21

True.

Front 22

True or false? Opioids cause bronchoconstriction and urticaria due to leukotriene release.

Back 22

False.

Opioids cause bronchoconstriction and urticaria due to histamine release. NSAIDs cause bronchoconstriction due to increased leukotriene concentrations.