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Hydrochlorothiazide and atenolol combination antihypertensive therapy: effects of drug initiation order

J A Johnson1, Y Gong, K R Bailey

  • 1College of Pharmacy, University of Florida, Gainesville, Florida, USA. Johnson@cop.ufl.edu

Clinical Pharmacology and Therapeutics
|July 3, 2009
PubMed

Insights

The order of initiating hydrochlorothiazide (HCTZ) and atenolol impacts blood pressure reduction in combination therapy. Starting with HCTZ then adding atenolol yielded greater BP lowering than the reverse sequence.

Area of Science:

  • Cardiovascular Medicine
  • Pharmacology
  • Hypertension Management

Background:

  • Combination antihypertensive therapy is common, often involving thiazide diuretics and beta-blockers.
  • The influence of drug initiation sequence on treatment outcomes in combined therapy remains understudied.

Purpose of the Study:

  • To investigate the effect of drug initiation order on blood pressure (BP) response in combination antihypertensive therapy.
  • To compare BP lowering effects between hydrochlorothiazide (HCTZ)/atenolol and atenolol/HCTZ sequences.

Main Methods:

  • Randomized trial involving patients with uncomplicated hypertension.
  • Patients received either HCTZ or atenolol monotherapy, followed by the addition of the alternative drug.
  • BP responses were analyzed by race and order of drug initiation.

Main Results:

  • Significant racial differences in monotherapy BP response: Black patients responded better to HCTZ, while white patients responded better to atenolol.
  • These racial differences diminished during combination therapy.
  • Initiating with HCTZ followed by atenolol (HCTZ + atenolol) resulted in greater BP reduction compared to initiating with atenolol followed by HCTZ (atenolol + HCTZ).

Conclusions:

  • The sequence of drug initiation significantly affects BP lowering in HCTZ/atenolol combination therapy within the initial 4-6 months.
  • Optimal BP control was not achieved in all patients even with optimal dosing of the combination therapy.

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