Brainscape's Knowledge GenomeTM

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


See full index

Year 3 - Reproduction > Pharmacology in pregnancy and breast feeding > Flashcards

Pharmacology in pregnancy and breast feeding Flashcards

1
Q

Certain physiological changes during pregnancy have implications for drug therapy and may affect any of the four basic kinetic processes namely?

A

1) Absorption
2) Distribution
3) Metabolism
4) Excretion

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

Absorption changes during pregnancy - Oral?

A
  • May be more difficult “morning sickness” nausea/vomiting
  • Increase in gastric emptying and gut motility
  • This is unlikely to be a problem with regular dosing, but may affect single doses
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Absorption changes during pregnancy - Intramuscular?

A

Blood flow may be increased, so absorption may also increase using this route

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

Absorption changes during pregnancy - Inhalation?

A

Increased cardiac output and decreased tidal volume may cause increased absorption of inhaled drugs

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

Distribution changes of drugs within pregnancy?

A

Increase in plasma volume and fat will change distribution of drugs.
= Increased Vd

Greater dilution of plasma will decrease relative amount of plasma proteins.
= Increased Fraction of Free Drug

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

Metabolism changes of drugs within pregnancy?

A

Oestrogen and progestogens can induce or inhibit liver P450 enzymes, increasing or reducing metabolism.

Examples:

  • Phenytoin levels reduced (due to induction of metabolism)
  • Theophylline levels increased (due to inhibition of metabolism)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Excretion changes of drugs within pregnancy?

A

GFR is increased in pregnancy by 50% leading to increased excretion of many drugs.

This can reduce the plasma concentration, and can necessitate an increase in dose of renally cleared drugs.

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

Functions of the placenta?

A

Attach the fetus to the uterine wall

Provide nutrients to the fetus

Allow the fetus to transfer waste products to the mother’s blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Exchange of materials across the placenta - Mother to foetus?

A 
Oxygen 
Glucose 
Amino acids 
Lipids, fatty acids & glycerol 
Vitamins 
Ions; Na, Cl, Ca, Fe 
Alcohol, nicotine + other drugs 
Viruses 
Antibodies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Exchange of materials across the placenta - foetus to mother?

A

Carbon dioxide
Urea
Other waste products

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

Concepts of placental transfer?

A

Depends on:

1) Molecular weight (smaller sizes will cross more easily)
2) Polarity (non-polar cross more readily)
3) Lipid solubility (lipid soluble drugs will cross)

Placenta may also metabolise some drugs

Safest to assume all drugs will cross placenta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What size do most drugs cross the placenta?

A

Most drugs withMW < 500 Da cross the placenta. MW > 1000 Da do not

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

Which charge allows most drugs cross the placenta?

A

Non-ionized drugs cross the placenta more easily than ionized drugs

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

Effect of lipophilicity on placental transfer?

A

High lipophilicity will increase placental transfer

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

Why may drugs and metabolites accumulate within a foetus?

A

As many drugs and metabolites are excreted within the amniotic fluid which is swallowed again

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is teratogenicity?

A

First trimester toxic drugs

17
Q

What is fetotoxicity?

A

Second and third trimester toxic drugs

18
Q

How are some drugs teratogenic?

A

Folate Antagonism

Neural Crest Cell
Disruption

Endocrine Disruption: Sex Hormones

Oxidative Stress

Vascular Disruption

Specific Receptor- or Enzyme-mediated

Teratogenesis

19
Q

Which drugs can cause flat antagonism? what effect is there?

A

Two groups of drugs

  • Block the conversion of folate to THF by binding irreversibly to the enzyme (eg methotrexate, trimethoprim)
  • Block other enzymes in the pathway (eg phenytoin, carbamazepine, valproate)

Key process in DNA formation and new cell production. Tend to result in neural tube, oro-facial or limb defects

20
Q

How is methotrexate teratogenic, what can it cause?

A

Folate antagonism - Block the conversion of folate to THF by binding irreversibly to the enzyme

Tend to result in neural tube, oro-facial or limb defects

21
Q

How is trimethoprim teratogenic, what can it cause?

A

Folate antagonism - Block the conversion of folate to THF by binding irreversibly to the enzyme

Tend to result in neural tube, oro-facial or limb defects

22
Q

How is phenytoin teratogenic, what can it cause?

A

Folate antagonism - Block other enzymes in the pathway

Tend to result in neural tube, oro-facial or limb defects

23
Q

How is carbamazepine teratogenic, what can it cause?

A

Folate antagonism - Block other enzymes in the pathway

Tend to result in neural tube, oro-facial or limb defects

24
Q

How is valproate teratogenic, what can it cause?

A

Folate antagonism - Block other enzymes in the pathway

Tend to result in neural tube, oro-facial or limb defects

25
Q

How are retinoids (e.g. istretinoin) teratogenic, what can it cause?

A

Neural crest cell disruption

Problems

  • Aortic arch anomalies
  • Ventricular septal defects
  • Craniofacial malformations
  • Oesophageal atresia
  • Pharyngeal gland abnormalities
26
Q

How are NSAIDs teratogenic, what can it cause?

A

Enzyme-mediated teratogenesis

NSAIDs causing orofacial clefts and cardiac septal defects

27
Q

What can fetotoxicity lead to?

A

Possible issues

  • Growth retardation
  • Structural malformations
  • Fetal death
  • Functional impairment
  • Carcinogenesis
28
Q

Examples of fetotoxic drugs?

A

ACE inhibitors/ARBs – renal dysfunction and growth retardation

29
Q

Anticonvulsants are teratogenic, what can it cause?

A

Valproate is associated with neural tube defects, as is carbamazepine and phenytoin

30
Q

Anticoagulants are teratogenic, what can it cause?

A

Warfarin is associated with haemorrhage in the fetus, as well as multiple malformations in the central nervous system and skeletal system.

31
Q

Anti-hypertensives are teratogenic, what can it cause?

A

ACE inhibitors cause renal damage and may restrict normal growth patterns in the unborn child.

32
Q

NSAIDs are teratogenic, what can it cause?

A

Premature closure of the ductus arteriosus.

33
Q

Alcohol are teratogenic, what can it cause?

A

Fetal alcohol syndrome/effects

34
Q

Retinoids are teratogenic, what can it cause?

A

Ear, CNS, cardiovascular, and skeletal disorders

35
Q

Drugs to avoid during breast feeding?

A 
Cytotoxics
Immunosuppressants
Anti-convulsants (not all)
Drugs of abuse
Amiodarone
Lithium
Radio-iodine

Year 3 - Reproduction (25 decks)

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