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[e-drug] WHO-ISH hypertension guidelines (cont)

E-drug: WHO-ISH hypertension guidelines (cont)
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An important aspect of the management of hypertension is the high incidence of
clinical confusion, when the patient's hypertension does not respond to
rationally prescribed drug treatment, between patient nonadherence and
pharmacologic nonresponse to the drug(s) prescribed.  The extent of this
confusion is described in the February issue of J Hypertension by Profs. Michel
Burnier, Hans Brunner, and their colleagues in Lausanne.  The abstract of the
paper follows.

TITLE: Electronic compliance monitoring in resistant hypertension: the basis
for rational therapeutic decisions
Journal of Hypertension  VOLUME: 19  ISSUE: 02  PAGES: 0335-0341
RECEIVED: 16 June 2000 ACCEPTED: 10 October 2000
AUTHORS: Michel Burnier, Marie Paule Schneider, Arnaud Chiolero, Claire Lise
Fallab Stubi, Hans R. Brunner
ADDRESS: *Division of Hypertension and Vascular Medicine and Policlinique
Medicale Universitaire, Lausanne, Switzerland

Objective
Incomplete compliance is one of several possible causes of uncontrolled
hypertension. Yet, non-compliance remains largely unrecognized and is falsely
interpreted as treatment resistance, because it is difficult to confirm or
exclude objectively. The goal of this study was to evaluate the potential
benefits of electronic monitoring of drug compliance in the management of
patients with resistant hypertension.
Methods
Forty-one hypertensive patients resistant to a three-drug regimen (average
blood pressure 156/106 ± 23/11 mmHg, mean ± SD) were studied prospectively.
They were informed that for the next 2 months, their presently 
prescribed drugs would be provided in electronic monitors, without 
any change in treatment, so as to provide the treating physician with 
a measure of their compliance.
Thereafter, patients were offered the possibility of prolonging the monitoring
of compliance for another 2 month period, during which treatment was adapted if
necessary.
Results
Monitoring of compliance alone was associated with a significant improvement of
blood pressure at 2 months (145/97 ± 20/15 mmHg, P <0.01). During 
monitoring, blood pressure was normalized (systolic < 140 mmHg or 
diastolic <90 mmHg) in one-third of the patients and insufficient 
compliance was unmasked in another 20%. When analysed according to 
tertiles of compliance, patients with the lowest compliance exhibited 
significantly higher achieved diastolic blood pressures (P = 0.04). 
In 30 patients, compliance was monitored up to 4 months and drug 
therapy was adapted whenever necessary. In these patients, a further 
significant decrease in blood pressure was obtained (from 150/100 ± 
18/15 to 143/94 ± 22/11 mmHg, P = 0.04/0.02).
Conclusions
These results suggest that objective monitoring of compliance using electronic
devices may be a useful step in the management of patients with refractory
hypertension, as it enables physicians to take rational decisions based on
reliable and objective data of drug compliance and hence to improve blood
pressure control.
KEYWORDS: hypertension, humans, patient compliance, drug therapy, drug failure
(end of abstract)

The technique of electronic monitoring of patient adherence/compliance is
presently in transition from research-only use, to use in specific clinical
situations where ambiguity between nonadherence and pharmacologic 
nonresponse has substantial medical and economic importance, e.g., 
drug-resistant hypertension, HAART in HIV infection without reduction 
in viral load.  The transition from research to practice is 
facilitated by falling costs of
electronic monitoring, such that an electronic monitor with a 3-year functional
lifetime has about the same cost as a 1-month's supply of one of the newer
antihypertensive drugs.  Another economic comparator is the cost of the
diagnostic maneuvers done to search for pathologic reasons for
"drug-refractory" disease -- in hypertension, this means workup for renal
artery stenosis, pheochromocytoma, elevated intracranial pressure; in HIV
infection it may trigger expensive drug switches, genetic sequencing studies
for drug-resistant HIV, and the like.   Needless to say, drug switches and
expensive tests are unnecessary when poor adherence is objectively identified
as the basis for nonresponse to prescribed drug treatment.  Useful background
information on the practicalities of electronic monitoring is a monograph of
the Swiss Pharmaceutical Society in Pharmactuel, v. XIV: Science and Pharmacy
Monograph #6: Compliance.

As the Lausanne group have pointed out in the above-cited article and
elsewhere, it has come as a big disappointment that adherence problems in
hypertension have not been altered to any substantial extent by the transition
from older, inconvenient, side-effect ridden drugs (alpha methyl dopa,
hydralazine, clonidine, and others) to once-daily drugs that have discernible
side-effects only in a small minority of patients, most of whom can find an
alternative drug that gives them no discernible side-effects.  It appears from
this and other findings with electronic monitoring methods that adherence
problems are attributes mainly of people, not of diseases or drugs.   With a
few exceptions, people tend to discontinue unpleasant drugs sooner than
well-tolerated ones, but the quality of day-to-day execution of prescribed drug
regimens seems to be about the same during the period of persistence with
treatment.

One would hope that these new perspectives, in the discernment of which the
Lausanne group have played a leading role, are incorporated into the new
guidelines.

John Urquhart, MD, FRCP(Edin)
Professor of Pharmaco-epidemiology, Maastricht University, Maastricht NL
Chief Scientist, AARDEX Ltd/APREX Corp, Zug CH & Union City, CA, USA
Professor of Biopharmaceutical Sciences, UCSF, San Francisco
home office: 975 Hamilton Ave, Palo Alto, CA 94301 USA
email: urquhart@ix.netcom.com

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