Skip to Main Content

++

SOURCE

++

Source: Ward KE. Pregnancy and lactation: therapeutic considerations. In: DiPiro JT, Talbert RL, Yee GC, Matzke GR, Wells BG, Posey LM, eds. Pharmacotherapy: A Pathophysiologic Approach. 10th ed. New York, NY: McGraw-Hill; 2017. http://accesspharmacy.mhmedical.com/content.aspx?bookid=1861&sectionid=146066717. Accessed May 17, 2017.

++

DEFINITION

++

  • Therapeutic issues affecting both mother and child, from planning for pregnancy through birth.

++

PATHOPHYSIOLOGY

++

  • Delayed gastric emptying and vomiting may alter drug absorption during pregnancy.

  • Increased gastric pH may affect absorption of weak acids and bases.

  • Higher estrogen and progesterone levels may alter liver enzyme activity and increase elimination of some drugs but accumulation of others.

  • Maternal plasma volume, cardiac output, and glomerular filtration increase by 30–50% during pregnancy, possibly lowering plasma concentration of renally cleared drugs.

  • Increased body fat may increase volume of distribution of fat-soluble drugs.

  • Reduced plasma albumin concentrations may increase volume of distribution of highly protein-bound drugs; however, unbound drugs more rapidly cleared by liver and kidneys.

  • Placenta is organ of exchange between mother and fetus for a number of substances, including drugs.

  • Drug molecular weights affect drug transfer across placenta:

    • Molecular weights >500 daltons (D) cross readily.

    • Molecular weights from 600 to 1000 D cross more slowly.

    • Molecular weights >1000 D (eg, insulin and heparin) do not cross in significant amounts.

  • Lipophilic drugs (eg, opiates and antibiotics) cross placenta more easily than water-soluble drugs.

++

CLINICAL PRESENTATION

++
SIGNS AND SYMPTOMS
++

  • Pregnancy-influenced issues.

    • Common during pregnancy:

      • Constipation.

      • Hemorrhoids.

      • Gastroesophageal reflux disease (GERD)

      • Nausea/vomiting.

    • Hyperemesis gravidarum (severe nausea/vomiting causing weight loss >5% of prepregnancy weight and ketonuria) occurs in 1–3% of pregnant women.

    • Gestational diabetes mellitus (GDM) more common in African Americans, Native Americans, Asian Americans, Hispanic Americans, and Pacific Islanders.

    • Hypertension, including:

      • Gestational hypertension: Pregnancy-induced hypertension without proteinuria.

      • Preeclampsia: Hypertension with proteinuria.

      • Eclampsia: Preeclampsia with seizures (medical emergency)

      • Chronic hypertension: Diagnosed prior to pregnancy with or without overlying preeclampsia.

    • Venous thromboembolism (VTE), with risk factors in pregnancy of:

      • Increasing age.

      • History of thromboembolism.

      • Hypercoagulable conditions.

      • Operative vaginal delivery or cesarean section.

      • Obesity.

      • Family history of thrombosis.

  • Acute care issues that may arise in pregnancy.

    • Headache.

    • Urinary tract infections.

    • Sexually transmitted infections (STIs)

  • Chronic illnesses that may occur in pregnancy.

    • Allergic rhinitis.

    • Asthma.

    • Diabetes mellitus.

    • Epilepsy.

    • HIV infection.

    • Hypertension.

    • Depression.

  • Labor and delivery.

    • Preterm labor.

    • Group B Streptococcus infection.

    • Cervical ripening and labor induction.

    • Labor analgesia.

++

DIAGNOSIS

++

  • Refer to individual disorders for diagnostic considerations.

++

DESIRED OUTCOMES

++

  • Provide preconception interventions to help ensure optimal pregnancy outcomes.

  • Relieve symptoms associated with pregnancy-influenced medical disorders.

  • Prevent congenital malformations caused by medication exposure.

  • Goals for GDM:

    • Fasting plasma glucose <90–99 mg/dL (5–5.5 mmol/L)

    • 1-hour postprandial plasma glucose concentrations < /= 140 mg/dL (7.8 mmol/L) or less.

    • 2-hour postprandial glucose <120–127 mg/dL (6.7–7 mmol/L)

++

TREATMENT: GENERAL APPROACH

++

  • Principles for selecting medications during pregnancy:

    • Select drugs used safely for long periods.

    • Prescribe doses at lower ...

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.