Pharmacy Issues in Pregnancy- 20

Question 1

When can conception occur.

Answer 1

Conception date might be the day sex occured or some days later as sperm can live in body for up to 5 days.

Question 2

When can prenatal death occur.

Answer 2

weeks 1 and 2

Question 3

when can major morphological abnormalities occur

Answer 3

Weeks 3-7

Question 4

when can physiological defects and minor morphological abnormalities occur

Answer 4

Weeks 8-38

Question 5

What are the 3 stages of foetal development and when do they occur.

Answer 5

Blastocyst formation- 0-16 days
Organogenesis 17-60 days
Histogenesis 61 days- full term

Question 6

What physiological changes occur during pregnancy.

Answer 6

CV- Increased heart rate and decreased BP
GI- Decreased gastric acid secretion and gastric emptying
Renal- Decreased bladder capacity and urinary control.

Question 7

What are the routes of the routes of transfer during pregnancy

Answer 7

Placenta
Respiratory function (gas exchange)
Excretory function (maintains water and pH balance)
Resorptive function (like GI tract)

Question 8

What does the quantity of drug reaching the foetus depend on

Answer 8

The physio-chemical characteristics of the molecule and maternal pharmacokinetic parameters.

Question 9

What are the three groups of degree of placental transfer

Answer 9

High: drug crosses rapidly, at equilibrium foetal conc close to the maternal pharmacological concentration

Limited: foetal concentration is lower than maternal concentration

Excess: Foetal concentration is higher than maternal

Question 10

What are maternal factors to consider when prescribing in pregnancy

Answer 10

Implications of not taking the drug
Maternal choice
Gestation
Co-Morbidities

Question 11

What are foetal factors to consider when prescribing in pregnancy

Answer 11

Risk of congenital malformations (weeks 1-8)
Risk of organ toxicity
Withdrawls post partum

Question 12

What are drug factors to consider during pregnancy

Answer 12

Altered ADME
Narrowing of theraputic index
Safer alternative
Ability to cross placenta
Topical v Systemic
Adverse affects

Question 13

What are common ailments related to pregnancy

Answer 13

Nausea and Vomiting- morning sickness
Haemorrhoids
Acid Reflux
UTI’s/Thrush
Anaemia
Infections

Question 14

What is morning sickness when and why does it happen and how is it treated.

Answer 14

Nausea & Vomiting in 70-80% of all pregnant women
4-8 weeks gestation- rarely after 16 weeks

Hormonal, neurological, physical factors
increased hCG hormone, decreased gastric emptying)

Treatment is by anti-emetics

Question 15

What are the causes of constipation and Haemorrhoids in pregnancy and how are they treated.

Answer 15

Constipation- Decreased motility of smooth muscle caused by an increase in progesterone or use of iron supplements.
Treated using bulk-forming laxatives.

Haemorrhoids- Enlarging of uterus exerts pressure, causes venous dilation.
Treated using anaesthetic creams or ointments.

Question 16

How is indigestion caused in pregnancy and what is the treatment.

Answer 16

Caused increased gastric pressure due to the foetus.

Treated using gaviscon alginates
Have small frequent meals, avoid triggers foods.

Question 17

How is thrush caused during pregnancy and what are the treatments.

Answer 17

Caused by hormonal changes in vaginal environment.

Treated via topical agents eg clotrimazole canestan cream or fluconazole one tablets oral (2nd line).

Question 18

How are UTI’s caused in pregnancy and what are the treatments.

Answer 18

UTIsare very common duringpregnancy.
(growing foetus can put pressure on the bladder andurinary tract. This traps bacteria or causes urine to leak).

Do not treat OTC – refer to GP

Question 19

Why is anaemia caused during pregnancy and what is the treatment

Answer 19

Iron deficiency can cause anaemia during infancy, spontaneous abortion, premature delivery, low birth weight of infant.

Treated using Iron supplements- variety of doses, usually 200mg FeSO4 or other iron salts –depending on tolerability. Also consider diet- leafy veg, cereals.

Question 20

What are common conditions experienced in pregnancy.

Answer 20

Hypertension and pre-eclampsia
Gestational diabetes
Venous thromboembolism (VTE)
Obstetric cholestasis

Not for management in Community Pharmacy- although will be seen in Primary Care / GP.

Question 21

What is a teratogen.

Answer 21

a substance, organism or process that causes malformations in a foetus (congenital abnormalities)

Question 22

What can teratogenic substances cause in the foetus

Answer 22

Physical effects (structural abnormalities, dysfunctional growth-e.g 1st 6 weeks Heart & CNS- congenital heart defects or neural tube defects)

Behavioural effects- i.e effects on brain which manifest as behaviour – avoid psychotropic drugs.

Question 23

What are major teratogenic drugs in humans

Answer 23

Anticoagulants
Warfarin

Antidepressants
Lithium

Anticonvulsants
Valproic acid
Carbamazepine

Chemotherapy
6-mercaptopurine
Methotrexate
Cyclophosphamide

Hormones
Androgens
19-Norsteroids

Retinoids
Isotretinoin
Acitretin
Thalidomide

Question 24

What are the 5 FDA categories of teratogenic drugs

Answer 24

A - drug is well-studied and poses no threat to a developing baby

B – drug less-studied, but probably still low-risk

C is a drug that has not been studied and therefore the risk is unknown

D-based on animal or human data, may pose a risk

X means the drug, based on animal or human data, causes birth defects or there is no benefit for its use during pregnancy. Not recommended in pregnancy.

Question 25

What are counselling points for taking drugs while breastfeeding

Answer 25

Insufficient evidence – advisable to administer only essential drugs to a mother during breast feeding
Use drugs with short half life
Feed just before mother takes medication (trough level)
Lipid soluble drugs diffuse into breast milk : concentrate because of high fat content of milk.
Generally, the quantity/conc of drug is too small to be of concern