Chronic Hypertension in Pregnancy Clinical Trial
Official title:
Pharmacokinetics of Amlodipine Besylate at Delivery and During Lactation
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.
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.
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