Medications during pregnancy Flashcards
How do you alter care for someone with hypothyroidism during pregnancy? [1]
Untreated or under-treated hypothyroidism in pregnancy can lead to several adverse pregnancy outcomes, including miscarriage, anaemia, small for gestational age and pre-eclampsia.
Levothyroxine can cross the placenta and provide thyroid hormone to the developing fetus. The levothyroxine dose needs to be increased during pregnancy, usually by at least 25 – 50 mcg (30 – 50%).
- Treatment is titrated based on the TSH level, aiming for a low-normal TSH level.
How do you manage hypertension during pregnancy:
- which medicines should be stopped [3]
- which medicines can be continued [3]
Medications that should be stopped as they may cause congenital abnormalities:
* ACE inhibitors (e.g. ramipril)
* Angiotensin receptor blockers (e.g. losartan)
* Thiazide and thiazide-like diuretics (e.g. indapamide)
Continued:
* Labetalol (a beta-blocker – although other beta-blockers may have adverse effects)
* Calcium channel blockers (e.g. nifedipine)
* Alpha-blockers (e.g. doxazosin)
Women with epilepsy should take [drug, dose & frequency] daily from before conception to reduce the risk of neural tube defects.
Women with epilepsy should take folic acid 5mg daily from before conception to reduce the risk of neural tube defects.
Which anti-epileptic drugs are safe in pregnancy? [3]
Levetiracetam, lamotrigine and carbamazepine are the safer anti-epileptic medication in pregnancy
Which anti-epileptic drugs are not safe in pregnancy? [2]
Why/ [2]
- Sodium valproate is avoided as it causes neural tube defects and developmental delay
-
Phenytoin is avoided as it causes cleft lip and palate
*
Which drugs are considered safe in pregnancy for patients with RA? [3]
Which is first line? [1]
- Hydroxychloroquine is considered safe during pregnancy and is often the first-line choice
- Sulfasalazine is considered safe during pregnancy
- Corticosteroids may be used during flare-ups
Describe the risk / benefits of when considering medication in pregnancy [2]
When prescribing:
benefit to the mother should always outweigh risk to fetus
the risk of acute maternal disease may be greater than risk of teratogenicity
How does pregnancy alter PK of drugs? [4]
Slow gastric emptying and reduced absorption of drugs
Increased maternal plasma volume: causes lowered serum levels of drugs making them ineffective eg anticonvulsants
Increased maternal hepatic metabolism: causes plasma levels of drugs to fall
Increased renal perfusion and elimination of drugs: cleared by the kidneys in pregnancy causes plasma levels to drop
Name three drugs that have increased renal perfusion during pregnancy [3]
What is the clinical significance of this? [1]
Amoxicillin, Digoxin, Lithium
- Increased renal perfusion and elimination of drugs: cleared by the kidneys in pregnancy causes plasma levels to drop
What is the difference between a teratogen and drugs that cause adverse fetal effects? [1]
Agents that cause permanent alteration of form or function
Retinoids cause teratogenicity via which mechanism? [1]
Neural crest cell disruption
DES, Fertility drugs, OCP cause teratogenicity via which mechanism? [1]
Endocrine disruption
trimethoprim causes teratogenicity via which mechanism? [1]
When can / can’t trimethoprim be given during pregnancy? [1]
Folate antagonism
- not recommended in the first 12 weeks
misoprostol, aspirin, ergotamine cause teratogenicity via which mechanism? [1]
Vascular disruption
A patient presents with these teeth - which drug was likely used during pregnancy to cause this? [1]
Tetracyclines
A patient presents with this problem - which drug was likely used during pregnancy to cause this? [1]
Phenytoin induced cleft palate
A baby is born like this - what was likely taken to cause this? [1]
Thalidomide
What is the dose of folic acid should take pre-conception for:
- healthy women [1]
- NTD, epilepsy, multiple pregnancy, SCD [1]
Start Folic Acid x 2-3 months pre-conception
400 micrograms/day – healthy women
5 milligrams/day - NTD, Epilepsy, Multiple pregnancy, sickle cell disease
Describe the effect of using tobacco during pregnancy [+]
Low birthweight,
microcephaly, facial clefts
Increased risks of placenta previa, placental abruption, ectopic pregnancy, and PPROM
Reduced fetal oxygenation resulting in IUGR
Excessive alcohol consumption usually defined as >[]g/day during pregnancy [1]
Excessive alcohol consumption usually defined as >80g/day
Describe the effects of alcohol consumption during pregnancy [2]
Associated with spontaneous miscarriage in first trimester, even with low levels of intake 1,2
Fetal alcohol syndrome with chronic exposure
Describe the effects / presentation of fetal alcohol syndrome [+]
- short palpebral fissure
- thin vermillion border/hypoplastic upper lip
- smooth/absent filtrum
- learning difficulties
- microcephaly
- growth retardation
- epicanthic folds
- cardiac malformations
Effects of cocaine during pregnancy? [5]
- spontaneous miscarriage
- Facial and skeletal anomalies
- Intestinal atresia
- Mental & growth retardation
- Placental abruption
Describe the effects of heroin, methadone or opiates during pregnancy [3]
- Placental vasoconstrictor so IUGR can occur
- Mental & growth retardation
- Placental abruption
Which non pharmacological drug is as effective as other anti emetics during pregnancy? [1]
Powdered root ginger as effective as other anti-emetics
Describe the treatment ladder for HG [4]
Hyperemesis gravidarum treatment dependent on severity: anti-emetics + thiamine 1.5mg od + Prednisolone 16mg od + Parental fluids + TPN1
Anti-acids during pregnancy - give examp;es of which are safe
- H2 antagonists [2]
- PPIs [1]
H2 antagonists:
- Cimetidine and Ranitidine are safe
PPIs:
- Omeprazole - however used only for protracted cases where the above haven’t been effective
Which analgesics are safe during pregnancy (include when they are / not safe w/ regards to gestation)
Paracetamol
- safe
Aspirin
- Best avoided in late pregnancy as labour delayed and prolonged and increased risk of maternal and fetal
haemorrhage
NSAIDs
- Avoid in general: causes closure of PDA, NEC & pulmonary hypertension
Opoids:
- in general safe in short term use
- If on long term opioids inform neonatal team at delivery- risk of neonatal withdrawal
Which NSAID is preferred post-partum? [1]
Which opiod? [1]
Ibuprofen
Di-hydrocodiene or tramadol used at lowest dose for shortest duration
Which laxatives should be avoidded as they can cause uterine contractions? [2]
Senna, Bisacodyl
Which antifungals are safe [2] and unsafe [3]
Topical imidazoles (e.g. clotrimazole; econazole):
- Safe as poorly absorbed
Systemic antifungal (e.g. fluconazole,griseofulvin, terbinafine)
- unsafe
- Avoid pregnancy for at least 6 months after treatment completed
Which of the following causes NTD and facial clefts during pregnancy
Rifampicin
Isoniazide
Ethambutol
Trimethoprim
Streptomycin
Which of the following causes NTD and facial clefts during pregnancy
Rifampicin
Isoniazide
Ethambutol
Trimethoprim
Streptomycin
Which of the following causes ototoxicty during pregnancy
Rifampicin
Isoniazide
Ethambutol
Trimethoprim
Streptomycin
Which of the following causes ototoxicty during pregnancy
Rifampicin
Isoniazide
Ethambutol
Trimethoprim
Streptomycin & other aminoglycosides
NB: Erythromycin safe
Which antibiotix drug class can cause dysplasia of bones if given during pregnancy? [1]
Tetracyclines
β-blockers are effective and safe in the [] trimester.
β-blockers are effective and safe in the 3rd trimester.
Which drugs are used to control hypertensive crises during pregnancy? [2]
IV labetalol or hydralazine are used to control hypertensive crises.
Which drug is used for severe pre-eclampsia and eclampsia? [1]
MgS
When is labetolol CI? [1]
Avoid Labetalol in asthmatics
Which drugs are safe for gestation diabetes? [2]
Which should be avoided? [1]
Sulphonylureas can cause fetal hyperinsulinemia & neonatal hypoglycemia therefore best avoided
Metformin does not cross the placenta and is therefore safe in pregnancy.
Which anticoagulants are safe / unsafe during pregnancy?
DOACS:
- Unsafe - cause bleeding risk
Low molecular weight heparins (LMWH) are safe in pregnancy
Warfarin
- unsafe
What is the a potential risk of when give levothyroxine during pregnancy? [1]
Some suggested association with
unilateral kidney agenesis
Which vaccines should be avoided in early pregnancy? [3]
Avoid rubella vaccine (although no evidence that it is teratogenic) and MMR or Polio in early pregnancy
Describe the cART rec. for pregnancy [3]
Which drug should be given during labour? [1]
tenofovir DF or abacavir with emtricitabine or lamivudine as a nucleoside backbone.
During labour, zidovudine should be administered intravenously until the umbilical cord is clamped.
Which drugs can be used to supress lactation (e.g. after perinatal death) [2]
Carbergoline
- now first line
Bromocriptine
- is a dopamine receptor agonist thus inhibits prolactin release
