Extent of use of immediate-release formulations of calcium channel blockers as antihypertensive monotherapy by primary care physicians: multicentric study from Bahrain.
BACKGROUND
The issue of cardiovascular safety of calcium channel blockers (CCBs) has been widely debated in view of reflex increase in sympathetic activity induced by immediate release (IR) / short acting formulations. It is generally agreed that such CCBs should not be used alone in the management of hypertension.


OBJECTIVE
We have determined the extent to which primary care physicians prescribe CCBs as monotherapy, especially the immediate release formulations, in the management of uncomplicated hypertension and diabetic hypertension - with an emphasis upon the age of the patients. SETTING, DESIGN AND METHODS: A retrospective prescription-based study was carried out in seven out of 18 Health Centres in Bahrain. The study involved a registered population of 229,300 representing 46% of registered individuals, and 35 physicians representing 43% of all primary care physicians. The data was collected between November 1998 and January 1999 using chronic dispensing cards.


RESULTS
In all categories CCBs were the third commonly prescribed antihypertensive as monotherapy, with a prescription rate of 11.1% in uncomplicated hypertension, 18% in diabetic hypertension and 20.1% in elderly patients above 65 years of age. Nifedipine formulations were the most extensively prescribed CCBs. Almost half of the CCB-treated patients were on IR-nifedipine, whereas IR-diltiazem and IR-verapamil, and amlodipine were infrequently prescribed.


CONCLUSIONS
Prescription of IR-formulations of CCBs as monotherapy by primary care physicians does not conform with recommended guidelines. In view of concerns about the safety of such practice, measures to change the prescribing pattern are required.
Sequeira
R P
RP
Department of Pharmacology and Therapeutics, College of Medicine and Medical Sciences, Arabian Gulf University, Bahrain. sequeira@agu.edu.bh
Jassim Al Khaja
K A
KA
Mathur
V S
VS
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000959:Antihypertensive Agents / Q000008:administration & dosage*; D001445:Bahrain; D002121:Calcium Channel Blockers / Q000008:administration & dosage*; D002626:Chemistry, Pharmaceutical; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D017723:Drug Utilization Review; D005260:Female; D019983:Guideline Adherence / Q000706:statistics & numerical data*; D019538:Health Care Surveys; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D011320:Primary Health Care / Q000592:standards* / Q000706:statistics & numerical data; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
D000959:Antihypertensive Agents; D002121:Calcium Channel Blockers