Prescribing in Special Populations: Pregnancy, Lactation and Paediatrics

Question 1

Can pregnancy affect pharmacokinetics of drugs?

Answer 1

• yes
• all of:
  Absorption
  Distribution
  Metabolism
  Elimination

Question 2

In pregnancy pharmacokinetics can be affected. Which of the following does NOT occur in a pregnant women in relation to drugs and distribution?

1 - increased plasma volume so drug dose may be reduced
2 - increased albumin content meaning less active drug
3 - loading doses of drugs like Amiodarone, Aminophylline and Phenytoin to bind protein, followed by a treatment dose
4 - potential toxic effect of large loading dosages of drugs (some patients may have low proteins)

Answer 2

2 - increased albumin content meaning less active drug

• albumin decreases meaning there is more active in the blood

Question 3

Can hormones in pregnancy affect drugs?

Answer 3

• yes
• some drugs can be induced by sex hormones
• for example estrogen has been shown to induce lamotrigine (epilepsy and mood stabiliser), meaning a larger dose is required, or patients symptoms may return

Question 4

Can cardiac output affect drugs in pregnancy?

Answer 4

• yes
• increased cardiac output increases eGFR
• increased eGFR can excrete drugs quicker

Question 5

What does teratogenicity mean?

1 - normal physiological development
2 - effect drugs have on the liver
3 - association between drugs and cancer
4 - abnormal physiological development

Answer 5

4 - abnormal physiological development
- drugs can be teratogenic and cause birth defects in pregnant women

• also need to be aware of toxic of adverse events. For example, if mum is taking opioids then this can cause respiratory distress in babies

Question 6

Are the majority of drugs able to cross the placenta, or are they stopped from crossing?

Answer 6

• most drugs are able to cross the placenta

Question 7

Which trimester is most sensitive to teratogenic, toxic and adverse effects?

1 - 3rd trimester
2 - 2nd trimester
3 - 1st trimester
4 - equally bad in all 3 trimesters

Answer 7

3 - 1st trimester
- most development occurs here

Question 8

Which of the following is NOT a known teratogenic drug?

1 - ACI-I
2 - lithium
3 - metformin
4 - carbamazepine

Answer 8

3 - metformin

• the 3 other drugs are and should be stopped in pregnancy

Question 9

Which of the following drugs has been associated with floppy baby syndrome?

1 - Benzodiazepines
2 - β-blockers
3 - Calcium channel blockers
4 - Heparin

Answer 9

1 - Benzodiazepines

Question 10

Which of the following drugs has been associated with growth defects, bradycardia, hypoglycemia?

1 - Benzodiazepines
2 - β-blockers
3 - Calcium channel blockers
4 - Heparin

Answer 10

2 - β-blockers

Question 11

Which of the following drugs has been associated with uterine effects?

1 - Benzodiazepines
2 - β-blockers
3 - Calcium channel blockers
4 - Heparin

Answer 11

3 - Calcium channel blockers

Question 12

Which of the following drugs has been associated with osteoporosis?

1 - Benzodiazepines
2 - β-blockers
3 - Calcium channel blockers
4 - Heparin

Answer 12

4 - Heparin

Question 13

Which of the following drugs has been associated with post-term risk, bleeding, premature ductus closure?

1 - Benzodiazepines
2 - NSAIDs
3 - Calcium channel blockers
4 - Heparin

Answer 13

2 - NSAIDs

Question 14

Why are older drugs preferred when prescribing to pregnant women?

1 - safer than newer drugs
2 - toxic profile is lower than newer drugs
3 - we know which drugs are safe
4 - all of the above

Answer 14

3 - we know which drugs are safe
- safer to know drugs that we know a lot about

Question 15

Is pharmacokinetics affects in paediatrics?

Answer 15

• yes
• bodies are still developing
• topical medications are different in children as they have thinner skin

Question 16

What is the key feature when prescribing to paediatrics to ensure they receive an optimal amount?

1 - age
2 - gender
3 - weight / body surface area
4 - breast feeding or not

Answer 16

3 - weight / body surface area