Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Reproduction > Pharmacology in Pregnancy > Flashcards

Pharmacology in Pregnancy Flashcards

1
Q

What percentage of pregnant women will take a drug during pregnancy?

A

50-90%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

List some absorption changes in pregnancy?

A
  • Oral route changes due to ‘morning sickness’/Increase in gastric emptying and gut motility
  • Intramuscular (Blood flow may be increased -^absorption)
  • Inhalation (Increased CO, decreased tidal volume - can increase absorption)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

List some distribution changes in pregnancy?

A
  • Increases in plasma volume and fat

- Greater dilution of plasma will decrease relative amount of plasma proteins ^fraction of free drug

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

List some metabolism changes in pregnancy?

A

-Oestrogen/Progestogens can induce/inhibit P450 enzymes, increase/reduce metabolism.
(Eg Phenytoin reduced/Tehophylline increased)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

List some excretion changes in pregnancy?

A
  • GFR ^ - ^Excretion

- Can reduce plasma conc, so need to increase dose of renally cleared drugs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the pharmacodynamic changes in pregnancy?

A
  • May affect site of action and receptor response to drugs

- Efficacy/adverse effects may be different

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Do most drugs cross the placenta?

A

Yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What does placental transfer depend on?

A
  • Molecular weight
  • Polarity (non-polar crosses easier)
  • Lipid solubility
  • Charge
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the distribution differences in fetal pharmacokinetics?

A
  • Circulation different
  • Less protein binding - more ‘free drug’ available
  • Little fat, different distribution
  • Relatively more blood flow to brain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the metabolism differences in fetal pharmacokinetics?

A
  • Less enzyme activity (increases with gestation)

- Different isoenzymes to adults

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the excretion differences in fetal pharmacokinetics?

A
  • Excretion into amniotic fluid, swallowed and can allow recirculation
  • Drugs and metabolites can accumulate in amniotic fluid
  • Placenta not functioning at delivery - can be issues with excretory function
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What issues are there with sodium valproate (anti-convulsant) in pregnancy?

A

Teratogenicity

Neural tube defects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What trimester does teratogenic drugs affect?

A

First trimester

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What trimesters do fetotoxic drugs affect?

A

Second and Third timester

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

List some mechanisms of teratogenicity

A
  • Folate Antagonism
  • Neural Crest Cell Disruption
  • Endocrine Disruption: Sex Hormones
  • Oxidative Stress
  • Vascular Disruption
  • Specific Receptor- or Enzyme-mediated Teratogenesis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What defects are usually seen in folate antagonism?

A

Neural tube defects
Oro-facial defects
Limb defects

17
Q

List some drugs involved in folate antagonism

A

Methotrexate, Trimethprim (Block coversion of Folate to THF)

Phenytoin, Carbazepine, Valproate (Block other enzymes in pathway)

18
Q

What defects may arise from neural crest cell disruption?

A 
Aortic arch anomalies 
Ventricular septal defects
Craniofacial malformations
Oesophageal atresia 
Pharyngeal gland abnormalities
19
Q

What class of drugs may be involved in neural crest cell disruption?

A

Retinoids (eg isotretinonin)

20
Q

Give an example of drugs involved in enzyme-mediated teratogenesis?

A

NSAIDs causing orofacial clefts and cardiac septal defects

21
Q

List some possible issues from fetotoxicity?

A
  • Growth retardation
  • Structural malformations
  • Fetal death
  • Functional impairment
  • Carcinogenesis
22
Q

Give an example of a fetotoxic drug?

A

ACE inhibitors/ARBs - renal dysfunction and growth retardation

23
Q

List some examples of known teratogens to avoid in pregnancy?

A 
Anticonvulsants (Valproate)
Anticoagulants (Warfarin)
Antihypertensive agents (ACE inhibitors)
NSAIDs
Alcohol
Retinoids
24
Q

List some drugs to avoid in lactation

A
  • Cytotoxics
  • Immunosuppressants
  • Anti-convulsants (not all)
  • Drugs of abuse
  • Amiodarone
  • Lithium
  • Radio-iodine
  • Also avoidance of some herbal remedies (Fenugreek, comfrey)
25
Q

What are the principles to consider when prescribing for women of child-bearing age?

A

Always consider possibility of pregnancy (planned or not!)
Warn women of possible risks
When treating medical conditions, advise women to attend before getting pregnant if planning to (optimise treatment)
Discuss contraception
If necessary, do not prescribe without contraception
Try non-pharm treatment first.
Use lowest effective dose.
Avoid first 10 weeks of pregnancy if possible.
Dont under treat disease which may be harmful to fetus.

26
Q

What are the principles to consider when prescribing in breastfeeding?

A
  • Avoid unnecessary drug use
  • Check up to date info - if safe in paeds, likely to be safe in breastfeeding
  • Choose drugs that reduce infant exposure
27
Q

What is the first line therapy used in pregnancy for hypertension?

A

Labetolol

28
Q

What antihypertensives are used during pregnancy for hypertension?

A

Combined alpha + beta blockers - eg labetolol
Hydralazine
Nifedipine
Methyldopa

29
Q

When may labetolol be contraindicated?

A

Asthmatics

Some cardiac conditions (bradycardias, cardiac failure)

30
Q

What may be used in women with symptomatic pre-eclampsia to treat/prevent seizures?

A

Magnesium sulphate

31
Q

What antihypertensives are CONTRAindicated in pregnancy?

A

ACE Inhibitors
Angiotensin Receptor Blockers
Spironolactone

32
Q

What simple analgesias are used in pregnancy?

A

Paracetamol
Dihydrocodeine/Codeine
Aspirin (But avoid in labour!)
Entonox

33
Q

What simple analgesias are CONTRAindicated in pregnancy?

A

NSAIDS - Ibuprofen/Diclofenac

Can cause premature closure of ductus arteriosus, fetal oliguria, oligohydramnios

34
Q

What drugs make up Entonox?

A

Oxygen

Nitrous oxide

35
Q

What opiates are commonly used in labour?

A

Morphine
Pethidine
Diamorphine
Remifentanyl PCA

Often co-prescribe with anti-emetic

36
Q

When may local anaesthetic be used in labour?

A
  • Before large bore IV cannula insertion
  • After delivery to suture an episiotomy/vaginal tear
  • Pudendal nerve block
37
Q

What are some contraindications to epidural use in labour?

A 
Thrombocytopenia,
Coagulopathy
Raised ICP
Local sepsis
Septic shock
Allergy to local anaesthetic
Recent anticoagulants
38
Q

When may spinal anaesthesia be used?

A

Most caesarean sections

Reproduction (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions