Drugs in Pregnancy Flashcards
What is meant by teratogen?
Damaging to foetus
-> especially in first half of pregnancy as this is the most vulnerable and can affect embryogenesis
What are some preventable terogens which mothers are advised to avoid?
Alcohol
Tobacco
Recreational drugs
What can alcohol in pregnancy cause to happen?
Foetal alcohol syndrome
What can smoking in pregnancy cause to happen?
Low birth weight
Preterm birth
Cerebral palsy
Learning difficulties
What can use of recreational drugs in pregnancy cause to happen?
Low birth weight
Withdrawal symptoms
Learning and behavioural problems
RECAP- pharmocokinetics?
Effect of the body on the drug
RECAP- pharmacodynamics?
Effect of the drug on the body
->maybe remember as the body moves, the drug does not, so pharmacodynamics is the effect on the body??
What can be given for nausea and vomiting in pregnancy?
Cyclizine- antihistamine
Prochlorperazine- phenothiazine
Doxylamine/oyridoxine combo (Xonvea) also first line
->second line= ondanestron, metoclopramide
What can be given for hypertension in pregnancy?
Labetolol
Nifedipine
Methyldopa
Hydralazine
->ACEi and ARBs are teratogenic so need to be changed as soon as pregnancy confirmed
What can be given for epilepsy in pregnancy?
Carbamazepibe
Lamotrigine
->always give high dose folic acid
What could occur if phenobarbitone is given in pregnancy for epilepsy?
Cardiac malformations
What could occur if sodium valproate is given in pregnancy for epilepsy?
Neural tube defect
Facial clefts
What is given for gestational diabetes?
Metformin
->also safe for type2 dia in pregnancy, insulin is also safest
What should be given for thromboembolism in pregnancy?
Low molecular weight heparin
What could occur if warfarin is given in pregnancy for thromboembolism?
Foetal Warfarin syndrome
What can be given for management of asthma in pregnancy?
Short-acting beta2 agonists, LABAs, oral and inhaled corticosteroids all safe
->important to have good control of asthma in pregnancy
What can be given for headaches/migraines in pregnancy?
Paracetamol
Sumatriptan for acute treatment of migraine
Propanolol- lowest effective dose
->ibuprofen should be avoided in 3rd trimester
What are the risks of morphine based medications in pregnancy?
Risk of neonatal respiratory depressionW
When are morphine based meds commonly used in pregnancy?
As analgesia for delivery
Which morphine based drug should be avoided during lactation?
Codeine- can cause infant opiate toxicity
What is the general advice on taking antidepressants and antipsychotics in pregnancy?
Weight the risk vs benefits in treatment
SSRI’s may be indicated if benefits outweigh positives
Lithium may be used in pregnancy for antidepressant/antipsychotic purposes but what are the risks?
Cardiac anomaly- Ebstein’s anomaly
Diazepam may be used in pregnancy for antidepressant/antipsychotic purposes but what are the risks?
Cleft lip/palate
->old studies
Quetiapine may be used in pregnancy for antidepressant/antipsychotic purposes but what are the risks?
Large baby
Poor neonatal adaption syndrome
List some antibiotics which are safe in pregnancy.
Penicillin
Macrolide- use only if no alternative
Cephalosporins
List some antibiotics which are NOT safe in pregnancy.
-Tetracycline- effects skeletal development
-Sulphonamides- avoid first trimester, folate antagonist
-Aminoglycosides- auditory/vestibular nerve damage, risk greatest with streptomycin
Okay to check you were taking that in, which antibiotic is an antagonist to folate and therefore cannot be taken in the first semester of pregnancy?
Sulphonamides
Are cancer treatments generally safe in pregnancy?
No- most cytotoxic drugs are teratogenic
What can you use before prescribing drugs to ensure they are safe for pregnancy?
BNF
What happens to the volume of distribution of drugs in pregnancy?
Increased
->increased plasma volume and fat increases distribution
What happens to GFR in pregnancy?
Increases by 50%
->this leads to higher excretion of drugs, higher medication doses may be required
Are drugs able to cross the placenta?
Yes, as do alcohol, nicotine and recreational drugs
->nearly all drugs, except those with a high molecular weight e.g. insulin and heparin
List some of the factors which increase the chances of the drug crossing the placenta.
Lipid-soluble, unionised drugs
Increased length of exposure
Stage of pregnancy
When in the pregnancy is the greatest risk of foetal abnormalities due to teratogenic drugs?
Early pregnancy during organogenesis
Fototoxicity?
Drugs which have toxic effects to the foetus
When can warfarin cause most damage to the foetus and what could happen?
If given in 2nd or 3rd trimester, can cause intracranial haemorrhage
When can NSAIDs cause most damage to the foetus and what could happen?
If given in 3rd trimester, can cause premature closure of ductus arteriosus resulting in neonatal pulmonary hypertension
When can beta blockers cause most damage to the foetus and what could happen?
Beta blockers given in late pregnancy may result in neonatal hypoglycaemia
