This document discusses drug therapy during pregnancy and its effects. It covers: - How physiological changes in pregnancy impact drug absorption, distribution, metabolism and excretion. This affects the pharmacokinetics of drugs in pregnant women. - Drugs can pass through the placenta to the fetus in varying amounts depending on their properties. Their effects on the embryo/fetus range from no effect to serious issues like malformations or death. - Identifying teratogenic (birth defect-causing) drugs is challenging as effects may be subtle or delayed. Care must balance risk to the fetus with benefits of treatment for the mother's health. - The nurse's role is to provide education to pregnant

1. DRUG THERAPY DURING
PREGNANCY
Developed By
D. Ann Currie , R.N.,M.S.N.

2. • PHYSIOLOGICAL CHANGES DURING
PREGNANCY AND THEIR IMPACT ON DRUG
THERAPY
• EVERY SYSTEM IN THE BODY IS EFFECTED
BY PREGNANCY
• PHARMACOKENETICS OF DRUGS IS
EFFECTED BY PREGNANCY

3. PHARMACOKENETICS OF DRUGS
DURING PREGNANCY
• ABSORPTION- DECREASED GI MOTILITY
CAUSES INCREASED DRUG ABSORPTION.
• DISTURBUTION- PROTIEN BINDING IS
DECREASED CAUSES INCREASED FREE
DRUG TO BE AVAILABLE.
• METABOLISM-INCREASED HEPATIC
METABOLISM OCCURS FOR SOME DRUGS

4. PHARMACOKENETICS
• EXCRETION- IN THE 3RD TRIMESTER
INCREASED RENAL BLOOD FLOW & GFR
CAUSES SOME DRUGS TO CLEAR THE BODY
FASTER.

5. DRUG THERAPY IN THE CHILDBEARING
CLIENT
 REQUIRES SPECIAL
CONSIDERATIONS
 IS CHALLENGING TO
PROVIDE EFFECTIVE
TX WHILE AVOIDING
HARM TO
EMBRYO,FETUS OR
NEONATE
 CENTERED ON
RISK/BENEFIT RATIO
 EFFECTS OF DRUGS
NOT ALWAYS
KNOWN

6. ANY DRUG TAKEN BY THE
PREGNANT OR BREASTFEEDING
CLIENT HAS THE POTENTIAL TO
REACH THE FETUS BY WAY OF

7. EFFECTS OF DRUGS ON THE EMBRYO,
FETUS, OR NEONATE
• NO EFFECT.
• LITTLE
• SERIOUS- FETAL TOXICITY
• SPONTANEOUS ABORTION
• DEATH
• FETAL MALFUNCTION
• FETAL MALFORMATIONS.

8. DRUG THERAPY DURING PREGNACY
• CENTERED ON RISK/BENEFIT RATIO
• EFFECTS OF SOME MEDICATION ARE KNOWN
• UNKNOWN- NEW MEDICATIONS,
DIFFERENT COMBINATIONS, DEFICIENCY
IN MATERNAL METABOLISM
• NO DRUG IS ABSOLUTELY SAFE.

9. RECENT STUDIES
• 75% OF PREGNANT CLIENTS USE 3-10
DIFFERENT DRUGS(PRESCRIPTION OR OTC’S)
OTHER THAN VITAMINS/MINERAL
SUPPLEMENTS DURING THEIR PREGNANCY.
• OTC’S WERE USED 4 TIMES THAT OF
PRESCRIPTION DRUGS.

10. TYPES OF DRUGS USED IN THE STUDY
BY PREGNANT CLIENTS
• DIETARY
SUPPLEMENTS
• ANTIEMETICS
• ANTACIDS
• TRANQUILIZERS
• HYPNOTICS
• ANTIBIOBIOTICS
• ANTIHISTAMINES
• ANALGESICS
• DIURETICS
• ETOH
• CNS DEPRESSANTS
• CNS STIMULANTS

11. DRUG LEVELS IN THE FETUS
REACHED 50-100% OF THE
MATERNAL BLOOD LEVELS

12. SELF TREATMENT WITH DRUGS
DURING PREGNANCY
• SELF TX OF MINOR ILLNESSES OR
DISCOMFORTS SHOULD BE DISCOURAGED
• *SELFTREATMENT OF ANY ILLNESSES
SHOULD BE DISCOURAGED
• WOMEN SHOULD BE INSTRUCTED TO KEEP
A COMPLETE RECORD OF ALL
MEDICATIONS TAKEN .

13. THE CHALLENGE OF PROVIDING
EFFECTIVE CARE/TX FOR THE
CHILDBEARING CLIENT
• AVOID HARM TO EMBRYO, FETUS,
NEONATE.
• DILEMMA UNFORTUNATELY THE RISK OF
MOST DRUGS HAVE NOT BEEN
ESTABLISHED.
• DESPITE NOT KNOWING DRUG THERAPY
DURING PREGNANCY

14. • CANNOT OR SHOULD NOT BE AVOIDED
BECAUSE THE HEALTH OF THE FETUS
DEPENDS ON THE HEALTH OF THE
MOTHER.
• FOR EXAMPLE: SEIZURES ,DM, MG, SLE,OR
INFECTIONS.

15. BIRTH DEFECTS
• INCIDENCE OF MAJOR STRUCTURAL
DEFECTS(ABNORMALITIES) IS ABOUT 6% OF
ALL PREGNANCIES.
• 3% ARE CAUSED BY DRUGS OR
ENVIRONMENTAL FACTORS/EXPOSURE
• 3% HAVE A UNKNOWN CAUSES

16. BIRTH DEFECTS
• 1/2 OF THE BIRTH DEFECTS ARE OBVIOUS AT
BIRTH.
• 1/2 OF THE BIRTH DEFECTS AREN’T
DISCOVERED UNTIL LATER IN LIFE OR
DISCOVERED DURING AN AUTOPSY
• INCIDENCE OF MINOR STRUCTURAL
ABNORMALIES IS NOT KNOWN.

17. BIRTH DEFECTS
• INCIDENCE OF FUNCTIONAL ABNORMALITIES
IS NOT KNOWN-GROWTH RESTRICTIONS,
MENTAL RETARDATION, AND LEARNING
DISABLITIES
• SOME ABNORMALITIES HAVE MULTIPLE
CAUSES-GENETIC FACTORS, ENVIRONMENTAL
FACTORS, CHEMICALS OR DRUGS.

18. TERATOGENIC
TERATOGENESIS
• TERAS-”MONSTER”
• GENSIS-”PRODUCING”
• BIRTH DEFECTS/DISTORTION OF GROSS
ANATOMY.
• EXAMPLES- CLEFT LIP/PALATE, CLUBFOOT,
NEURAL TUBAL DEFECTS, MISSING OR
MALFORMED LIMBS/FINGERS.

19. TERATOGENIC
• ALSO-BEHAVORIAL AND/ OR BIOCHEMICAL
ABNORMALITIES.
• TERATOGENESIS MAYBE DIRECT-IE-
MALFORMATIONS OF STRUCTURES
• OR INDIRECT-SUCH AS INTERFERING WITH O2
OR NUTRIENTS.

20. TERATOGENIC
• EXAMPLE OF KNOWN TERATOGENIC AGENTS:
• ONE TIME EXPOSURE IS THALIDOMIDE-
CAUSES MISSING LIMBS.
• CONT. OR PROLONG EXPOSURE IS ETOH-
CAUSES FAS.
• SEE HANDOUT FOR OTHER AGENTS.

21. FETAL EFFECTS FROM DRUGS DEPEND
ON SEVERAL FACTORS
• TIME- WHEN DRUG IS TAKEN IN
PREGNANCY.
• PREIMPLANTATION/PRESOMITE PERIOD-
CONCEPTION TO 2 WEEK
• HIGH DOSE- MAYBE
LETHAL/DEATH/ABORTIONS.
• LOW DOSE-MAYBE NOTHING.

22. • EMBRYONIC PERIOD-3-8 WEEKS
*FIRST TRIMESTER*
• GROSS MALFORMATIONS
• FETAL PERIOD-9-40 WEEKS(TERM)
• FUNCTION PROBLEMS RATHER THAN
GROSS ANATOMY-
*LEARNING DEFICITS &/OR BEHAVORIAL
ABNORMALIES

24. WHY IS IDENTIFICATION OF
TERATOGENIC AGENTS
SOMETIMES DIFFICULT TO
IDENTIFY?

25.  INCIDENCE OF CONGENITAL ANOMALIES IS
GENERALLY LOW.
 ANIMAL TESTS MAY NOT BE RELIABLE
 PROLONGED OR INCREASED EXPOSURE
MAYBE REQUIRED.
 EFFECTS MAYBE DELAYED OR NOT
RECONIZED.
 BEHAVIORAL EFFECTS ARE DIFFICULT TO
DOCUMENT.
 CONTOLLED EXPERIMENTS CANNOT BE
DONE ON HUMANS.

26.  DOCUMENTATION IS INCOMPLETE
 ONLY IN A LIMITED NUMBER OF DRUGS IS
THE TERATOGENIC EFFECTS KNOWN OR
PROVEN.
 LACK OF PROOF OF TERATOGENICITY
DOES NOT MEAN A DRUG IS SAFE IN
PREGNANCY
 MAY MEAN THERE IS A LACK OF
RESEARCH OR INFORMATION.

27. PROVING A DRUG IS A TERATOGEN
• 3 CITERIA MUST BR MET:
• 1. DRUG MUST CAUSE A CHARACTERISTIC SET
OF MALFORMATIONS.
• 2. IT MUST ACT ONLY DURNIG A SPECIFIC
WINDOW OF VULNERABILITY-3-8 WEEKS OF
GESTATION

28. • 3.THE INCIDENCE OF MALFORMATIONS
SHOULD INCREASE WITH INCREASED DOSAGE
& DURATION OF EXPOSURE.

29. PLACENTAL DRUG TRANSFER
• THE PLACENTA IS NOT A COMPLETE BARRIER.
• SOME DRUGS ARE STOPPED.
• SOME DRUGS(IN FACT MOST) ARE NOT.
• WAYS DRUGS ARE TRANSFER ACROSS- SIMPLE
DIFFUSION-ACTIVE TRANSPORT.

30. TRANSFER DEPENDS ON SEVERAL
FACTORS
• CHEMICAL PROPERTY OF THE DRUG
• MOLECULAR WEIGHT.
• PROTEIN BINDING CAPABILITIES.
• CHEMICAL CONFIQURATION.
• LIPID SOLUBILITY.*
• PERIOD OF TIME DRUG REMAINS IN
MATERNAL BLOODSTREAM
• HALFLIFE OF THE DRUG.

31. TRANSFER DEPENDS ON SEVERAL
FACTORS
• CONT.
• AMOUNT OF THE DRUG.
• PATHOLOGICAL PROCESSES OF THE
PLACENTA.
• WHEN IN THE PREGNANCY-INCREASED BLOOD
FLOW TO THE PLACENTA IN LAST PART OF
PREGNANCY.

32. MOST DRUGS TRANSFER AND ARE
AT 50-100% THAT OF THE
MATERNAL LEVELS * SOME DRUG
LEVELS ARE MORE THAN THE
MATERNAL LEVELS

33. • DRUGS THAT TRANSFER EASILY ARE LIPID
SOLUBLE.
• DRUGS THAT ARE DIFFICULT/HARD TO
TRANSFER ARE IONIZED DRUGS-HIGHLY
POLAR-OR PROTEIN BOUND.

34. HOW IS DATA COLLECTED ON
DRUGS WHICH CAUSE PROBLEMS
IN PREGNANCIES?
• NO HUMAN EXPERIMENTATION
• SYSTEMATIC COLLECTION AND ANALYZING
OF DATA ON DRUGS TAKEN BY PREGNANT
CLIENTS.
• REPORTING OF INFORMATION BY HEALTH
PROFESSIONALS.
• SEE FORM.

35. THE NURSE’S ROLE AND
RESPONSIBILITY IN DRUG THERAPY
IN THE CHILDBEARING CLIENT
• KNOWLEDGE (CURRENT &ACCURATE
INFORMATION)-
• PREGNANCY
• MEDICAL CONDITIONS
• MEDICAL TREATMENTS
• DRUGS AND CLIENT

36. EDUCATION OF
PREGNANT/PREPREGNANT CLIENTS
• PROVIDE ACCURATE INFORMATION WITH
RATIONALES
• INFORMATION SOULD BE CURRENT AND
BASED ON EVIDENCE.
• * ESTABLISH ENVIRONMENT CONDUCIVE
TO EXCHANCE OF INFORMATION*- TRUST.
• POTENTIAL HARM/RISKS.

37. EDUCATION
• BENEFITS
• COMMON SUBSTANCES & OTC DRUGS TO
AVOID IN PREGNANCY- ASA,ETOH,INCREASED
DOSES OF
MULTVITAMINS,CAFFIENE,CIGARETTE
SMOKING,ETC.
• AVOID SELF TX-OTC’S, DRUGS FORM MEXICO.

38. • ADVOCATE FOR CLIENTS AND GENERAL
PUBLIC.
• * SUPPORT*
• ASSIST WITH COPING IF CLIENT HAS TAKEN
A TERATOGENIC AGENT..WITH GUILT OR
FEAR…ASSOCIATED WITH DRUGS TAKEN IN
PREGNANCY.

39. PREGNANT CLIENT’S BILL OF
RIGHTS
“RIGHT TO KNOW”

40. For individual drugs see handout.