Pharmacokinetics of Amlodipine Besylate at Delivery and During Lactation
Condition: Chronic Hypertension in Pregnancy
MeSH terms: Hypertension, Pregnancy-Induced; Hypertension
Study type: Interventional
Phase: Phase 4

Summary: 
      This is a phase IV prospective trial to collect and analyze information about the maternal
      pharmacokinetics of amlodipine besylate at the time of delivery and during postpartum
      lactation. The study will also evaluate amlodipine concentrations in the infants of
      breastfeeding mothers who are taking amlodipine besylate for treatment chronic hypertension.
    

Detailed description: 
      We plan to evaluate the pharmacokinetics of amlodipine besylate at the time of delivery, to
      determine if transplacental passage of the drug occurs. We will also examine the drug
      kinetics in postpartum lactation to establish whether amlodipine is excreted into breast
      milk. The outcomes of interest are plasma concentration of amlodipine at delivery and the
      drug concentrations in blood and breast milk over a twenty-hour steady-state period following
      milk-supply establishment. Fifteen patients already taking 5 mg of amlodipine during
      pregnancy for the treatment of chronic hypertension will be recruited from the antepartum
      Obstetric Complications Clinic at Parkland Hospital. Only women who are breastfeeding will be
      eligible for the study. Patients who elect to participate in the study will continue their
      amlodipine 5 mg dosing through delivery and into the postpartum period. Maternal blood will
      be drawn within one hour of delivery and fetal cord blood collected at the time of delivery.
      Patients will then have blood drawn over a 24 hour period beginning on postpartum day 2 after
      delivery following administration of their once-daily amlodipine dose. At each blood draw,
      the patient will also use a breast pump to express breast milk for paired analysis. Both
      blood and breast milk amlodipine levels will be calculated for all samples. The levels will
      be used to determine the pharmacokinetics of amlodipine in the peri- and postpartum patient,
      including concentrations in plasma and breast milk.

      In addition to collecting maternal data, a range of clinical information will be collected on
      each study patient's infant including weight, Apgar scores, hemodynamic parameters, physical
      examination and hospital course. This information will be used to screen for any potential
      complications associated with infant exposure to amlodipine. An infant blood sample will also
      be obtained in conjunction with the routine neonatal blood collection that occurs at 1-2 days
      of postnatal life and this will be analyzed to determine serum amlodipine concentration in
      breastfeeding infants.
    

Intervention name(s): Amlodipine besylate
Intervention type(s): Drug
Intervention description(s): Pregnant and postpartum women will continue taking amlodipine besylate 5 mg for treatment of chronic hypertension as prescribed by their clinician.
Intervention MeSH terms: Amlodipine
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Amlodipine besylate; Breast milk; Pharmacokinetics; Chronic hypertension; Pregnancy