Pharmacology in Pregnancy and Breast Feeding Flashcards
What are the common conditions for which women are on medication during pregnancy or whilst breastfeeding?
Hypertension Asthma Epilepsy Migraine Mental health disorders Long term anti coagulant therapy
What absorption changes can occur during pregnancy?
Morning sickness may make oral route more difficult
Increase in gastric emptying and gut motility may affect single dose medication
Blood flow may be increased so absorption may increase
Increased cardiac output and decreased tidal volume may increased absorption of inhaled drugs
What distribution changes can occur during pregnancy?
Increase in plasma volume and fat increases drug distribution
Greater dilution of plasma will decrease relative amount of plasma proteins so increases fraction of free drug
What metabolism changes can occur during pregnancy?
Oestrogen and progesterone can induce or inhibit liver P450 enzymes, increasing or reducing metabolism
What excretion changes can occur during pregnancy?
GFR increases so increases excretion of drugs, can reduce plasma concentration therefore increase dose or renal cleared drugs
What are the functions of the placenta?
Attach foetus to uterine wall
Provide nutrients to foetus
Allow the foetus to transfer waste products to mother’s blood
What products are passed from the mother to foetus?
Oxygen Glucose Amino acids Lipids, fatty acids and glycerol Vitamins Ions Viruses Antibodies Alcohol, nicotine etc
What products are passed for the foetus to mother?
Carbon dioxide
Urea
What factors does placental transfer depend on?
Molecular weight
Polarity
Lipid solubility
Duration of drug exposure
What kind of effects can teratogenic drugs have on the foetus?
Neural crest cell disruption Folate antagonism Endocrine disruption Oxidative stress Vascular disruption
How do drugs cause folate antagonism?
Block conversion of folate to THF by irreversible binding to protein
Block other enzymes in pathway
What does folate antagonism tend to result in?
Neural tube, oro-facial or limb defect
What particular drug can cause neural crest cell disruption?
Retinoids
What problems can arise from neural crest cell disruption?
Aortic arch anomalies Ventricular septal defects Craniofacial malformations Oesophageal atresia Pharyngeal gland abnormalities
What problems can arise from the use of NSAIDs during pregnancy?
Orofacial clefts
Cardiac septal defects
