243 Pregnancy Flashcards

0
Q

How could we overcome the problem of morning sickness effecting absorption?

A

Change the timing of the dose

Can also give with an anti-emetic

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

How may pregnancy effect drug absorption?

A

Morning sickness- a tablet may not stay down in the stomach long enough to be absorbed.
Progesterone slows gastric emptying and can therefore leas to slower absorption and lower peak concentration.
This is a bigger problem for SINGLE doses rather than long term meds- these will build up over time

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

What does total body water increase by in pregnancy?

A

By About 81

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

What does increasing total body water mean for drugs in preggers women?

A

It should dilute the concentration of any drug, but as serum albumin falls and pregnancy steroids displace drugs from their binding proteins “free drug” levels may rise.

Example of drug effected: Thyroxine
Also assays are needed for anti-epileptic drugs

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

How does pregnancy effect enzymes? An example of a drug involved?

A

Pregnancy effects metabolism of drugs acting through cytochrome p450 enzymes

An important example is the enzyme which inactivates lamotrigene. This is induced by pregnancy.
So doses of lamotrigene need to be increased to get the same effect

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

How does pregnancy effect drug excretion?

A

A higher cardiac output (51 becomes 71) leads to an increase of 50% in GFR
Renally excreted drugs like penicillin are excreted faster
(Therefore in pregnancy we will use 500mg ampicillin tds not 250mg tds)

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

The increased GFR in pregnancy due to increased cardiac output causes physiological __________.?

A

Causes physiological glycosuria

Excretion of glucose in the urine

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

Beta Blockers are less likely to cause _______ because of the tachycardia which exists in pregnancy. This is due to physiological changes in pregnancy.

A

Less likely to cause bradycardia because it’s cancelled out by the tachycardia

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

Calcium channel blockers are less likely to decrease the total ________ resistance because this is already reduced in pregnancy.

A

Total peripheral resistance

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

What is teratogenesis?

A

Where a baby is born with a congenital abnormality (means a defect present at birth)
This can be induced by a drug
1-2% of babies are born with a congenital abnormality
Under 1 in 20 of these can be due to drugs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What two drugs, if they are given to a pregnancy woman, will result in the majority of fetuses being born with birth defects.

A

Methotrexate

Thalidomide

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

Most congenital abnormalities are multi-factorial, what does this mean?

A

A lot of drugs risk of teratogenicity is small.
(Example Valproate is linked with NTD’s in 1-2%)
Therefore if a baby is born with an abnormality it’s usually die to another factor such as Folate deficiency being a cofactor for NTDs.

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

How do most drugs cross the placenta into the baby? 

A

By simple diffusion.

This depends on concentration gradient and molecular weight.
Most drugs given to a mother will reach the fetus.

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

What’s one drugs that won’t eventually reach the foetus when given to the mother?

A

Heparin.
MW= 15000
Too big to cross into the foetus.

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

What drugs accumulate in the fetus due to fetal metabolism, therefore should be avoided in pregnancy?

A

Iodine
Gets concentrated in fetal thyroid

Labetalol
Accumulates in amniotic fluid of the baby

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

When is the maximum susceptibility period in pregnancy for teratogenic effects to occur?

A

Between 3-11 weeks of pregnancy, this is during organogenesis (when a mass of cells turn into organs)

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

Why does glucose tolerance decrease with advancing gestation? (Diabetes)

A

Because of the anti-insulin effects of the placentas substances:
lactogen, glucagon and cortisol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Increased oestrogen levels in pregancy increase serum levels of Globulin, which binds_______,________ and ______?

A

Thyroxine
Corticosteroids
Sex steroids

Note: free levels of hormone do not change

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Why is it important to control diabetes In pregnant women?

A

Poorly controlled diabetics have a high incidence of congenital abnormalities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

HOW can we optimise blood glucose control in pregnant diabetic women?

A

Using either more frequent doses of insulin OR Metformin
Usually over 4 daily injections of insulin is required.
Increase the frequency of Blood sugar monitoring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What abnormality can Phenytoin use cause in ?

A

Orofacial clefts

Eg cleft lip / palate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What two epilepsy drugs are most likely to cause NTDs?

A

Valproate

Carbamazepine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What epilepsy drugs are most likely to cause cardiac defects in ?

A

Valproate and phenytoin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

The risks of epilepsy drugs causing abnormalities increases with polypharmacy.
___% likely for just one AED
___% likely for two AEDs
___% likely for three AEDs

A

6-7% for one
15% for two
Up to 50% for three

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

For what AED is the risk of causing abnormalities dose dependent?

A

Valproate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Can you tell me some of the minor abnormalities associated with use of anti-convulsants in preganancy?

A

Low set ears 
Broad nasal bridge
Irregular teeth
Hypoplastic nails and digits 

But then again, even UNTREATED epilepsy is associated with an increased risk of congenital abnormality!!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What must women on epilepsy treatment receive pre-conception due to the mechanism of AEDs causing abnormalities being folate deficiency?

A

Must receive 5mg folate daily for at least 3 months pre-conception

Especially if any of the ones mentioned eg valproate, phenytoin, carbamazepine must be used

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

So, if these AEDs are causing abnormalities, should we take women who are pregnant off them and potentially not control their epilepsy?

A

No
Overall benefit of treatment outweighs the risk eg woman fitting and rolling over onto stomach damaging baby.

Newer anti-epileptics such as lamotrigene and gabapentin do not appear so risky but they aren’t entirely risk free!!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What are the hepatic enzyme inducing drugs to watch out for in pregancy?

A

Drugs such as carbamazepine, phenytoin, and phenobarbitone

30
Q

What is hyperthyroidism?

A

Over active thyroid. Produces too much thyroid hormone, if too much thyroid hormone then every function of the body tends to speed up.
Some of the symptoms include nervousness, irritability, heart racing etc

31
Q

What drug do we need to give daily, orally in the last 4 weeks of pregnancy, if a woman is taking hepatic enzyme inducing drugs, such as carbamazepine, phenytoin and phenobarbitone?

A

Need to give Vitamin K 10-20mg daily orally in LAST FOUR WEEKS of pregnancy.
This is because the baby is at risk of haemorrhagic disease.
Note: if corticosteroids are being given for fetal lung maturity, then dose needs to be increased.

32
Q

What is hypothyroidism?

A

Where patient has an underactive thyroid
Not enough thyroid hormone is produced.
Symptoms: tiredness, poor ability to tolerate cold, weight gain

34
Q

Radioactive _____ in treatment of HYPERthyroidism in pregnancy is absolutely contraindicated

A

Radioactive Iodine

35
Q

Both Carbaimazole and propylthiouracil cross the placenta in pregnancy, therefore will get into baby. What are these used to treat?

A

Used for HYPERthyroidism

Propylthiouracil crosses the placenta less than these

36
Q

What are completely safe to treat HYPERthyroidism in the short term if required to control the pregnant mothers symptoms?

A

beta blockers safe in short term

37
Q

How do we manage hypothyroidism in preganancy?

A

Aim to keep the mother euthyroid (normal thyroid function) during pregnancy.
Usually a pre-pregnancy dose will do this
If you’re monitoring how good your replacement therapy is rememeber that TSH (thyroid stimulating hormones) risk in the third trimester of pregnancy.

38
Q

When do levels of TSH (thyroid stimulating hormone) rise in preganancy?

A

In the THIRD trimester

39
Q

When prescribing for hypertension in pregancy, what do we need to differentiate between?

A

Pre-existing hypertension (existed before preganancy due to some other reason)
Benign gestational hypertension (hypertension occurring during pregancy)
pre-eclampsia (High blood pressure and lots of protein in the urine)

40
Q

What is pre-eclampsia?

A

Hypertension existing with protein in the urine

41
Q

When is there a fall in blood pressure during normal pregnancy?

A

The mid-trimester fall

42
Q

What are the anti hypertensives commonly seen in preganancy? (Hint: you have seen one of these in dispensing!)

A

Alpha methyl dopa
Nifedipine
Labetolol (orally and IV)
Hydralazine

43
Q

What antihypertensives classes are contraindicated in preganancy?

A

ACE inhibitors
ARBs
Diuretics

44
Q

When are drugs most likely to cause congenital abnormalities in a Child?which trimester!

A

First trimester

45
Q

During the second and third trimesters drugs may affect _____ & __________

A

May affect growth and functional development
May have toxic effects on fetal tissues
Growth effects may effect: kidneys and brain
Functional effects: include deafness

46
Q

When prescribing in preganancy, we also should think about paternal medication. Can you possibly think of any examples?

A

Finasteride: used for prostate problems
Gets excreted in semen
Can effect male fetal development

47
Q

Can omeprezole be used in pregnancy today?

A

Yes, updates to the SPC state it’s now safe in pregnancy.

Losec can be used (type of Omeprazole)

48
Q

What pharmacokinetic changes are present in a pregnant woman?

A

Increase in plasma volume
Reduction in serum albumin
Increase in renal function

All these parameters quickly go back to normal after lady has given birth
Eg Lamotrigine dose must be reduced after birth to avoid toxicity

49
Q

What types of laxatives should be avoided in unstable or near term pregnancys? Why?

A

Stimulant laxatives

due to uterine contractions

50
Q

What is first line for heart burn in pregnancy?

A

Antacids/ alginates such as Gaviscon

51
Q

Second line for heart burn in pregnancy?

A

GP / Hospital to treat with second lines if first line (antacids / alginates) haven’t worked.
h2 Receptor antagonist first line: Ranitidine
PPI of choice: Omeprazole

52
Q

What is used first line for pain relief in pregnancy ?

A

Paracetamol

53
Q

NSAIDS can potentially be used up to week ____ of pregnancy especially NSAID ______.
After this they can cause bleeding complications
In general NSAIDS are usually avoided in preganancy

A

NSAIDS can potentially be used up to week 30 of pregnancy especially NSAID Ibuprofen.
After this they can cause bleeding complications
In general NSAIDS are usually avoided in preganancy

54
Q

Note: frequent paracetamol use during late preganancy (20-30 weeks) has been associated with an increased incidence of wheezing or childhood asthma.

A

However Data ARE conflicting

55
Q

A woman presents at your pharmacy with morning sickness

What can you give / advise?

A

Not really anything to give for nausea and vomiting
GINGER Biccys are good! 
Advise to eat little and often
P6 Accupressue (wristband)
Avoid dehydration
Can use DIORALYTE to correct fluid and electrolytes lost

56
Q

Why does Hypermesis gravadium need hospital admission?

A

It is unstoppable vomiting in a pregnant woman
It can cause fluid and electrolyte disturbance and nutritional deficiency
It needs drugs that should only be given under supervision

57
Q

When a woman is admitted for treatment of Hypermesis gravadium, what is usually given first line?

A

1st line: Antihistamines

2nd line: metoclopramide/ Prochlorperazine

If vomiting still occurs: try Ondanasetron

This is in BNF

58
Q

WHO recommends breast feeding for the first ___months of life as it provides perfect nutrition

A

First six months

59
Q

One advantage of breast feeding is increased immune function for the baby. Why is this?

A

Mothers IgG antibodies can cross the placenta
IgM can also be produced to respond to infection
IgA produced also (but only if baby receives Colostrum- the first milk after birth) and breast milk

60
Q

What is colostrum?

A

Milk formed in late pregnancy in mothers breasts

It’s the first milk given to the child after birth

61
Q

What are some advantages to a baby of being breast fed?

A
Less incidence of:
diahorrea
Iron related aneamias 
Respiratory infections
Otitis media
Neonatal septicaemia 
Protects against sudden infant death syndrome
62
Q

What are the advantages to the mother of breast feeding?

A
Decreased risk of :
ovarian cancer
Breast cancer 
Hip fracture
Osteoporosis
Reduced blood loss post birth
63
Q

When considering drugs and breast feeding, things like age of baby, weight, hepatic / renal function, babies medication, baby exposed to medication debuting pregnancy or in breast milk yet need to be considered. Why does age need to be considered?

A

Age is really important during first few days of life as it’s much easier for medication to pass into mothers Breast milk at this point.
This is due to large gaps between alveolar cells

64
Q

Metronidazole Breast feeding information:

A

BNF states there’s a significant amount in milk
Manufacturer advises to avoid large single doses
BNF for children advises the same as above and also adds that metronidazole and breast milk are otherwise compatible- may even give milk a better taste!

65
Q

What has pH got to do with breast milk and drugs?

A

Breast milk is slightly more acidic than blood
This means Weak acids such as penicillins will have levels in breast milk of less than half that in maternal plasma.
Weak bases will become ionised in milk.
Eg isoniazid may have levels in breast milk greater than in maternal plasma
So pHs of drugs will determine whether they are at lower or higher concentrations in breast milk

66
Q

What are the 5 factors producing poor excretion into breast milk?

A
High molecular weight (over 600)
Highly protein bound
Weak acids
Short acting medication or preparation (peaks rapidly and gets eliminated from maternal plasma) 
No active metabolites
67
Q

Most medication causes no harm to breast fed babies.
There are however a few absolute contraindications
What are these?

A

Antineoplastic medications
Iodides
Amiodarone
Lithium

Toxicity can occur if any of these medications enter breast milk in pharmacological quantities

68
Q

Why with SSRIS is it better to choose fluoextine with a short half life over paroxetine with a long half life?

A

Longer half life fluoextine has an active metabolite with a long half life
Also premature babies generally have not so good excretory functions, this can make their half life much greater. This can lead to drug accumulation and adverse events

69
Q

Can codeine be used in breast feeding mothers?

A

No it should not be used

It can pass to the baby through breast milk and potentially cause harm

70
Q

Any alternatives to codeine for a breast feeding mother?

A

Tramadol- this is considered as an acceptable alternative in breast feeding based on low levels in breast milk, when given at the lowest effective dose for the shortest duration of time

71
Q

What drug can improve milk production if necessary in for example premature babies?

A

Domperidone

Does so by increasing prolactin secretion

72
Q

What drugs can cause an inhibition of lactation I.e stop as much Breast milk being produced so should be AVOIDED by mothers wishing to breast feed?

A

Diuretics
Anabolic steroids
Moderate/ heavy alcohol intake 