Presentation on theme: "Medications in Pregnancy"— Presentation transcript:
1 Medications in Pregnancy Dr Cate Price14 March 2015
2 Dr Cate Price GP – Flagstaff Hill Medical Centre Medical Advisor – Obstetric shared careMedical Educator – Sturt FleurieuVMO – WCH antenatal OPD
3 Learning ObjectivesTo have an understanding of safety categories for medications in pregnancyTo know when and where to seek advice regarding safety of medications in pregnancyTo learn examples of some “drugs of choice” for common conditions during pregnancy
4 Medications in Pregnancy General perception that any drug exposures during pregnancy pose a potential risk to the fetusAn Australian study showed that about 96% of women use some form of prescribed or non prescribed medication during pregnancy
5 TeratogensTeratogens are environmental agents introduced during pregnancy that interfere with development such that they induce or increase the incidence of a congenital (structural) malformation.DrugsInfections – Rubella, CMVChemicals – MercuryRadiationBehavioural teratogens – Alcohol, Valproic acidBehavioural and Structural – Rubella, Isotretinion
6 Teratogens Drugs to be avoided during pregnancy Isotretinoin – craniofacial, ear, cardiovascular and limb defects as well as structural CNS anomalies and neurodevelopmental problemsValproic acid – fetal valproate syndrome –facial dysmorphism and malformations including neural tube defects, cleft palate and cardiac anomalies as well as neurodevelopmental problems, can occur in > 10% of exposed infantsWarfarin – use between 6-12 weeks –nasal hypoplasia and stippled epiphyses. Use in later pregnancy – fetal CNS haemorrhage
7 Timing of exposure“All or none period” – first two weeks after conception or 2-4 weeks amenorrhoea from LMPGenerally believed that exposures during this time do not cause malformationsThe conceptus is a mass of dividing stem cells with minimal contact with the maternal circulation and which have not yet differentiated into organs
8 Timing of exposure Embryonic period 4-11 weeks amenorrhoea most critical period of developmentstructural defects – NTD, cardiac, orofacial(Thalidomide caused limb defects after exposure tween days post conception)
9 Timing of exposure Fetal period Exposure does not cause malformations May cause disruption of normally formed organs(NSAIDs, ACEI – impair fetal renal function –decrease fetal renal production and amniotic fluid volume – fetal joint contractures and pulmonary hypoplasia as a result of oligohydramnios)
10 Australian Categorisation system for prescribing drugs in Pregnancy https://www.tg.org.au/etg_demo/desktop/tgc/plg/5a57ea5.htm#categorya
11 CategoriesIncorrectly imply gradations of risk – B3 is not necessarily safer than CDo not take into account different stages of pregnancyOften assigned on the basis of animal studiesAssigned before release of drugs and often do not change despite new evidence
12 Information sourcesWomen’s and Children’s Hospital Drug Information in Pregnancy and Breastfeeding
13 Asthma in Pregnancy Ms C, age 36, is currently 9 weeks pregnant She has asthma for which she usesFluticosone - Salmeterol 1 puff bdSalbutamol prnHow would you advise her about her medications?
14 Asthma in PregnancyWhen her pregnancy was confirmed (at 5 weeks) her GP advised her to cease the seretide and to use ventolin as needed.Do you agree with this advice?
15 Asthma in PregnancyAt 6 weeks pregnant she had an URTI and needed to use her salbutamol several times a dayShe saw another GP who advised her she could use a preventer, but to use Budesonide rather than Fluticosone as this was a category A rather than a B3Is this reasonable advice?
16 Asthma in PregnancyShe feels her asthma is better controlled with the Seretide than the Budesonide and she is still needing to use her salbutamol several times a day.How do you advise her?
17 Asthma in Pregnancy Discussion points The most common potentially serious medical problem that can affect pregnant women1/3 can expect a worsening of their symptomsLess likelihood of severe asthma during pregnancy if the condition is well controlled when she conceivesAll women who are are pregnant or planning a pregnancy should be advised of the importance of continuing to use the asthma medication that best controls their asthma
18 Asthma in Pregnancy Discussion points Most asthma medications are inhaled – only small amounts of the drug enter the blood – cross the placentaIt is far better to treat asthma aggressively with inhaled preventers to avoid the need for oral corticosteroids
19 Asthma in Pregnancy She is happy to resume Seretide. Later that afternoon, she rings and is worried as she has read the CMI leaflet in the medication box and it says to avoid this medication in pregnancy.How do you advise her?
20 Hypertension in Pregnancy Ms P age 40 comes to you for pre natal counsellingShe was diagnosed with Hypertension 5 years ago and her BP is well controlled on Perindopril 5 mgsWhat do you advise her about her medication?
21 Hypertension in pregnancy You seem to remember that ACE inhibitors are contraindicated during pregnancy.Where would you get accurate, up to date advice?
22 Hypertension in Pregnancy Some commonly prescribed anti hypertensive drugs are contraindicated or best avoided before conception and during pregnancy None have been shown to be teratogenic. ACE inhibitors Angiotensin receptor blockers Diuretics Beta blockers Ca channel antagonistsACE inhibitors – feat renal dysfunction, oligohydramniosAngiotensin receptor blockers – dittoDiuretics – fetal electrolyte disturbanceBeta blockers ( except labetalol & oxprenolol) – fetal bradycardia, long term use atenolol – growth restrictionCa channle antagonists – maternal hypotension, fetal hypoxia
23 Hypertension in Pregnancy ACE inhibitors are not recommended in the second and third trimesters of pregnancyMethyldpoa is the drug of choice
24 Herbal Medication in Pregnancy Mary is pregnant with her first child.She is currently 30 weeks pregnant and you have seen her for shared careThe pregnancy has been uneventfulShe asks you about raspberry leaf tea as she has heard about it on MumsnetWhat do you know about Raspberry Leaf Tea?
25 Herbal Medication in Pregnancy Herbalists have long believed that raspberry leaf tea taken regularly during pregnancy can prevent complications and make delivery easier.Only one clinical study – no benefitDid not significantly shorten labour, reduce pain or prevent complicationsDouble blind placebo controlled study192 pregnant womenTreatment began at 32 weeks, 2.4 gms raspberry leaf daily
27 Herbal MedicationsMedications to be avoided – usually because of theoretical uterine stimulationAloe veraDong quai/AngelicaFeverfewArbor vitaeGoldensealBlack and Blue CohoshPassionflowerCascaraPennyroyalComfreyPokeweedSlippery Elm
28 Drugs of Choice Condition Drug of Choice Other suitable agents Comment Allergic RhinitisTopical agentsNa cromoglycateCorticosteroidsSystemic antihistaminesPheniramineLoratidineCetrizinePhenylephrineOxymetazolineXylometazolineTopical decongestants – theoretical concerns about vasoconstrictionCough/ColdParacetamolThroat lozengesCodeineDextromethorphanPseudoephedrinePhenyephrinePseudoephedrine/Phenylephrine -available in many cough/cold preparations - theoretical concerns about vasoconstriction
29 Drugs of Choice Constipation Dietary fibre Docusate Bisacodyl Psyllium ParaffinLactuloseLactose should be avoided in people with lactose intolerance and DiabetesDepressionSSRIsSNRIsTCAMirtazepineConflicting data regarding possible increase risk of cardiovascular defects in babies exposed to SSRIs. Reassuring long term neurodevelopmental dataDiarrhoeaCodeineLoperamideFeverParacetamolNSAIDsNSAIDs should be avoided in the third trimester because of fetal renal side effects and the potential to cause premature closure of the ductus arteriosus
30 Drugs of Choice Nausea and vomiting of pregnancy Ginger Vitamin B6 DoxylamineMetoclopramideOndansetronHeartburn/RefluxAntacidsSimetheconeH2 antagonistsOmeprazole and other PPIsRecent studies have shown that omeprazole is not associated with any increase risk of birth defects or other adverse pregnancy outcomesPainParacetamolCodeineMorphinePethidineNSAIDsNSAIDs should be avoided in the third trimester because of fetal renal side effects and the potential to cause premature closure of the ductus arteriosus