Pregnancy Pharmacology Flashcards
How might absorption be affected by pregnancy when taking medications orally, IM or inhaled?
Orally- gastric emptying slowed so single dose meds might be affected, nausea and vomiting may limit oral use
IM-increased blood flow means increased absorption
Inhaled- increased CO and decreased tidal volume may increase absorption
How does pregnancy affect the distribution of a drug?
Fat and plasma volume increase
Decrease in proteins means there will be more free drug
What effect can pregnancy hormones have on liver enzymes?
Oestrogen and progestogens can induce or inhibit liver P450 enzymes, increasing or reducing metabolism
How is excretion of drugs affected by pregnancy?
Excretion is increased due to raised GFR
What aspects of a drug will affect its ability to cross over the placenta?
Molecular weight (smaller sizes will cross more easily) Polarity (non-polar cross more readily) Lipid solubility (lipid soluble drugs will cross)
What effects on a foetus can retinoids have?
aortic arch anomalies ventricular septal defects craniofacial malformations oesophageal atresia pharyngeal gland abnormalities (disrupt the neural crest cells) (teratogenic)
What effects on a foetus can NSAIDS have?
Orofacial clefts
Cardiac septal defects
(teratogenic)
What effects do ACE and ARBs have on a foetus?
Renal dysfunction
Growth retardation
(Foetotoxic)
What effects do anticonvulsants have on a foetus?
Valproate is associated with neural tube defects, as is carbamazepine and phenytoin
Valproate also associated with ADHD and social difficulties when child is older
What effects do anti coagulants have on a foetus?
Warfarin is associated with haemorrhage in the foetus, as well as multiple malformations in the central nervous system and skeletal system
What drugs should be avoided in a breast feeding mother?
Cytotoxics Immunosuppressants Anti-convulsants (not all) Drugs of abuse Amiodarone Lithium Radio-iodine
What herbal remedies should be avoided in breast feeding?
Fenugreek and comfrey
