European Journal of Clinical Pharmacology

, Volume 26, Issue 1, pp 39–42 | Cite as

Should the acetylator phenotype be determined when prescribing hydralazine for hypertension?

  • L. E. Ramsay
  • J. H. Silas
  • J. D. Ollerenshaw
  • G. T. Tucker
  • F. C. Phillips
  • S. Freestone


The role of acetylator phenotype in determining the response to hydralazine when it was added to diuretic and β-blocker at doses not exceeding 200 mg daily was examined in 57 hypertensive patients. 81% of rapid acetylators needed 200 mg hydralazine daily compared to 38% of slow acetylators (p<0.01). Despite higher doses of hydralazine the blood pressure was controlled in only 27% of rapid acetylators compared to 65% of slow acetylators (p<0.02). The relation of acetylator phenotype to blood pressure response was statistically independent of initial blood pressure, age, sex, body weight and serum creatinine (p<0.005). Current recommendations on hydralazine dosage are unsatisfactory for the 40% of hypertensive patients who are rapid acetylators. We suggest measurement of the acetylator phenotype in patients who respond incompletely to 200 mg hydralazine daily. About 70% of these patients will be rapid acetylators in whom the dose of hydralazine can be increased safely.

Key words

acetylator phenotype hydralazine response hypertension blood pressure control lupus syndrome 


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Copyright information

© Springer-Verlag 1984

Authors and Affiliations

  • L. E. Ramsay
    • 1
  • J. H. Silas
    • 2
    • 1
  • J. D. Ollerenshaw
    • 1
  • G. T. Tucker
    • 1
  • F. C. Phillips
    • 1
  • S. Freestone
    • 1
  1. 1.University Department of TherapeuticsThe Royal Hallamshire HospitalSheffieldUK
  2. 2.The Hypertension Unit Clatterbridge HospitalBebington, WirralUK

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