title: Conversion from sustained-release to immediate-release calcium entry blockers: outcome in patients with mild-to-moderate hypertension.
abstract: We evaluated 110 patients with mild-to-moderate hypertension (diastolic blood pressure 95 to 110 mmHg) whose blood pressure was initially controlled on monotherapy with once-daily sustained-release calcium entry blockers; these patients were then switched to their respective immediate-release formulations TID. The study group consisted of 35 patients on diltiazem controlled delivery (CD) switched to immediate-release diltiazem, 41 patients on nifedipine gastrointestinal therapeutic system (GITS) switched to immediate-release nifedipine, and 34 patients on verapamil sustained-release (SR) switched to immediate-release verapamil. Outcome evaluation included a pair-wise comparison of the following during treatment with both formulations: blood pressure control, need for additional hypertensive agents, side effects, compliance, and cost of therapy. Blood pressure was controlled in 94% of patients switched from diltiazem CD to immediate-release diltiazem; 6% of patients required additional antihypertensive agents. Side effects and compliance were not significantly different between groups. Blood pressure was controlled in 78% of patients switched from nifedipine GITS to immediate-release nifedipine; 22% of patients required additional antihypertensive agents. Side effects, compliance, and cost of therapy were significantly different between groups. Side effects increased from 32% on nifedipine GITS to 58% on immediate-release nifedipine; and compliance decreased from 93% on nifedipine GITS to 76% on immediate-release nifedipine (P < 0.05). Blood pressure was controlled in 91% of patients switched from verapamil SR to verapamil immediate release; 9% of patients required additional antihypertensive agents. Side effects and compliance were not significantly different between groups, but immediate-release verapamil was significantly less expensive than verapamil SR.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Creighton University Medical Center, Omaha, Nebraska.
authors.forename: D E
authors.initials: DE
authors.lastname: Hilleman
authors.forename: S M
authors.initials: SM
authors.lastname: Mohiuddin
authors.forename: B D
authors.initials: BD
authors.lastname: Lucas
authors.forename: B
authors.initials: B
authors.lastname: Shinn
authors.forename: G N
authors.initials: GN
authors.lastname: Elsasser
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000187:drug effects; D003692:Delayed-Action Preparations; D004110:Diltiazem / Q000008:administration & dosage* / Q000627:therapeutic use; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D009543:Nifedipine / Q000008:administration & dosage* / Q000627:therapeutic use; D010349:Patient Compliance; D014700:Verapamil / Q000008:administration & dosage* / Q000627:therapeutic use
chemical_list: D003692:Delayed-Action Preparations; D014700:Verapamil; D004110:Diltiazem; D009543:Nifedipine