Ppt chapter 07-1

Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins

Chapter 7

Life Span: Pregnant or Breast-Feeding Women


Question

• Most drugs given during pregnancy will not pass to the fetus.

– A. True

– B. False


Answer

• B. False

• Rationale: Unlike the blood–brain barrier, the placenta allows most drugs to travel through the maternal circulation to the fetus.


Pharmacotherapeutics

• The important consideration in drug therapy for pregnant women is the potential adverse effects on the developing fetus.

• A clear clinical indication for drug therapy must exist before a drug is prescribed or self-administered.

• Some health problems occur secondarily to pregnancy and require drug therapy.

• If the fetus has a health problem, drugs are administered to the pregnant woman with the intent of treating the fetus as the drug passes through the placenta.


Pharmacokinetics

• Several physiologic and anatomic changes occur during pregnancy.

• These changes can alter the pharmacokinetics of drugs.

• The primary changes occur in the endocrine, GI, cardiovascular, circulatory, and renal systems.


Absorption

• Changes in the GI system are influenced by pregnancy hormones and mechanical pressure from the growing uterus.

• Progesterone decreases gastric tone and motility and prolongs stomach emptying time.

• Progesterone also promotes functional respiratory system changes during pregnancy.

• Tidal volume increases 30% to 40%, with a 50% increase in minute volume by term.


Questions

• What will be the effect of inhaled medications during pregnancy?

– A. Increased absorption

– B. Decreased absorption


Answer

• A. Increased absorption

• Rationale: Tidal volume increases 30% to 40%, with a 50% increase in minute volume by term. These increases, along with the pulmonary vasodilation that occurs during pregnancy, enhance the absorption of drugs that are inhaled.


Distribution and Metabolism

• Hemodynamic changes in the cardiovascular system alter drug distribution and metabolism.

• Drugs are also distributed into breast milk.

• Drugs that are widely distributed throughout the mother’s body are usually minimally passed into breast milk.

• Not all drugs present in breast milk are well absorbed by the neonate.

• Drug metabolism is not altered by pregnancy or breast-feeding.


Excretion

• By the third trimester, the renal blood flow has increased 40% to 50% from the prepregnancy level.

• The glomerular filtration rate increases by approximately 50%.

• Drug excretion rates may be increased during pregnancy.


Pharmacodynamics

• Two dramatic physical changes occur in the mother during pregnancy:

– By 32 weeks’ gestation, cardiac output is increased by 50%.

– From the second trimester on, arterial blood pressure is decreased.


Contraindications and Precautions

• Some drugs and vaccines are contraindicated during pregnancy, and others should be given with caution if they pose a threat to the developing fetus by passing through the placenta.

• Some drugs and vaccines can cause teratogenic effects (physical defects) in the developing fetus.

• The precise effects of drug therapy on the fetus are mostly undetermined.

• A drug is traditionally identified as a teratogen based on the findings of animal teratology studies.


Drugs Contraindicated in Pregnancy


Pregnancy Categories


Lactation Categories

• In 2005, the American Academy of Pediatrics Committee on Drugs published its updated recommendations on drugs and breast-feeding.

• The report identifies several categories of drugs and their potential to cause problems with breast-feeding.


Adverse Effects

• The common symptoms of pregnancy may mask the adverse effects of drug therapy.

• Administration of drugs during pregnancy takes careful evaluation of the effects of the drugs on the fetus.

• The critical period of organogenesis is from implantation up to approximately days 58 to 60 after conception.

• If drugs that cause teratogenic effects are administered during this period, major malformations of fetal organ systems may result.


Drug Interactions

• Drug interactions are unchanged during pregnancy and breast-feeding.


Question

• Which of the following are common complications of pregnancy?

– A. Heartburn

– B. Hypotension

– C. Nausea

– D. All of the above


Answer

• D. All of the above

• Rationale: All of the above are common complications of pregnancy, making it difficult to determine whether the pregnancy or medications that are prescribed during the pregnancy are causing the adverse effect.


Health Status• Several considerations must be taken into account when

assessing health status during pregnancy.

• First, if the patient has a preexisting condition that requires drug therapy, the health care providers must consider whether the prescribed drug therapy will have adverse effects on the fetus.

• Second, any adverse effects the pregnancy may have on the mother’s health must be identified because they may require changes in drug therapy.

• Third, if the pregnancy does induce changes in health status that require new drug therapy, any adverse effects of this drug therapy on the fetus will have to be determined.


Conditions of Concern

• Cardiovascular

– Changes occur in the cardiovascular system

• Seizure disorders

– Antiseizure medications have been shown to be teratogenic.

• Depression

– Unclear about long-term effects on the fetus

• Diabetes mellitus

– Increased incidents of congenital abnormalities


Life Span and Gender

• Teenage pregnancy continues to be a problem in the United States.

• Teenaged girls may be at additional risk for teratogenic drug effects because of sharing of prescription medication.


Lifestyle, Diet, and Habits

• The lifestyle, diet, and habits of pregnant or breast-feeding women can have a serious impact on the course of the pregnancy and the development of the fetus or infant.

• Alcohol is a known human teratogen.

• Cocaine abuse is also known to cause adverse fetal effects and is suspected to be a human teratogen.

• Opiate abuse does not appear to significantly increase the risk for congenital anomalies.


Environment

• Some changes in health status that occur in pregnancy require drug therapy to be administered in the hospital setting.

• However, most drug therapy given during pregnancy or breast-feeding is administered in the patient’s home.


Culture and Inherited Traits

• Cultural beliefs may affect whether a woman accepts certain drug therapies while she is pregnant or breast-feeding.

• Assess for these beliefs when managing drug therapy in the pregnant or breast-feeding woman.


Nursing Diagnoses and Outcomes• Risk for Injury to the fetus related to adverse effects of

maternal drug therapy

– Desired outcome: The patient will demonstrate therapeutic drug effects with minimal adverse effects to the fetus.

• Anxiety related to perceived danger of drug therapy to the fetus or infant

– Desired outcome: The patient’s anxiety will be minimal during drug therapy.

• Risk for Injury to the patient related to failure to receive needed drug therapy because of its potential adverse effects on the fetus or infant

– Desired outcome: The patient will not sustain an injury from choices made about receiving drug therapy.


Maximizing Therapeutic Effects

• An important element of patient teaching is adverse reactions to medications.

• Discuss the risks versus the benefits of the medication to the patient and unborn fetus.


Minimizing Adverse Effects

• Limiting drug use in pregnancy decreases maternal and fetal adverse effects.

• No drug can be considered absolutely safe when administered during pregnancy.

• Women of childbearing age should always be assessed for pregnancy before any drug therapy is initiated.

• During pregnancy, nonpharmacologic alternatives to drug therapy should be used if possible.

• Monitor the pregnant woman and the fetus for both therapeutic and adverse effects of drug therapy.

• When evaluating a patient, be careful to distinguish discomforts of pregnancy from possible adverse drug effects.


Providing Patient and Family Education

• The nurse’s role in counseling about pregnancy and fetal drug effects ideally begins before pregnancy.

• Informing women of childbearing age about fetal drug effects can help them make decisions about planning pregnancy and about what to do when they become pregnant.

• Patient and family education during pregnancy and breast-feeding is primarily focused on adverse effects to the fetus and infant.

• The pregnant patient should also be taught how to anticipate adverse effects of drug therapy and distinguish them from normal pregnancy-related problems.


Assessment and Evaluation

• Nursing management of drug therapy during pregnancy and lactation is considered effective when maternal therapeutic needs have been met without harm to the fetus or the breast-feeding infant.

• Other measures of effective drug therapy include successful patient- and family-oriented drug education.

• Assessment findings indicate that the mother and child are not experiencing adverse drug effects.

Documents

Ppt chapter 07-1