Evaluation of metoprolol versus diltiazem for rate control of atrial fibrillation in the emergency department.

OBJECTIVE: The purpose of this study was to compare the effectiveness and safety of the metoprolol and diltiazem administration in the Emergency Department (ED) for rate control of supraventricular tachycardia. METHODS: This was a retrospective cohort study of adult patients who presented to the ED with ventricular rates ≥120 beats per minute (bpm) and who received bolus doses of either intravenous metoprolol or intravenous diltiazem. The primary outcome was achievement of rate control, defined as heart rate < 110 bpm, at two hours after administration of the last bolus dose of metoprolol or diltiazem. Safety outcomes included occurrence of hypotension, defined as systolic blood pressure < 90 mmHg or diastolic blood pressure < 60 mmHg, and bradycardia, defined as heart rate < 60 bpm. RESULTS: There were 166 patients receiving metoprolol and 183 patients receiving diltiazem included in the study. The primary outcome, rate control at two hours after the last bolus dose of metoprolol or diltiazem was similar between the two groups (45.8% vs 42.6%, p = 0.590, respectively). The percentage of patients achieving rate control was also similar (47.0% vs 41.6%, p = 0.333) at one hour. At 0.5 h HR had a significantly greater numerical (diltiazem: 29.3 ± 23.1 bpm vs metoprolol: 21.8 ± 18.9 bpm, p = 0.012) and percent decrease (21.1% vs 15.94%, p = 0.014) in the diltiazem group compared to metoprolol. There was no significant difference in occurrence of bradycardia in the two groups (diltiazem: 3.83% vs metoprolol: 1.2%, p = 0.179). More patients in the diltiazem group compared to the metoprolol group experienced hypotension (39.3% vs 23.5%, p = 0.002). The difference in systolic hypotension events was not significantly different (9.29% vs 5.42%, p = 0.221), while the difference in diastolic hypotension events was significantly different (37.7% vs 22.3%, p = 0.002). CONCLUSION: There was no difference in acute rate control effectiveness two hours after the last bolus dose of diltiazem and metoprolol for supraventricular tachycardias. There was a significantly higher occurrence of hypotension in the diltiazem group which was driven by higher rates of diastolic blood pressures less than 60 mmHg.

Quality of compounded topical 2% diltiazem hydrochloride formulations for anal fissure.

AIM: To investigate the quality of topical 2% diltiazem formulations extemporaneously compounded by retail pharmacies openly offering drug-compounding services. METHODS: A participating healthcare professional wrote 12 prescriptions for compounded 2% diltiazem cream, with 2 refills allowed per prescription. The 12 sets of prescriptions were filled, at intervals of 1-2 wk between refills, at 12 different independent retail pharmacies that openly offer drug-compounding services in a major metropolitan region. The 36 resultant preparations, provided as jars or tubes, were shipped, as soon as each was filled, at ambient temperature to the study core laboratory for high-performance liquid chromatography (HPLC) analysis, within 10 d of receipt. For the HPLC analysis, 8 different samples of the topical diltiazem, each approximately 1 g in weight, were taken from prespecified locations within each container. To initiate the HPLC analysis, each sample was transferred to a 100 mL volumetric flask, to which methanol was added. The HPLC analysis was conducted in accordance with the laboratory-validated method for diltiazem in cream, ointment, and gel formulations. The main outcome measures were potency (percentage of label claim) and content uniformity of the compounded topical 2% diltiazem formulations. RESULTS: Of the 36 prescriptions filled, 30 were packaged in jars and 6 were packaged as tubes. The prescriptions were specifically for cream formulations, but 6 of the 12 pharmacies compounded 2% diltiazem as an ointment; for another pharmacy, which had inadequate labeling, the dosage form was unknown. The United States Pharmacopoeia (USP) standard for potency is 90%-115% of label claim. Of the 36 preparations, 5 (13.89%) were suprapotent and 13 (36.11%) were subpotent. The suprapotent prescriptions ranged in potency from 117.2% to 128.5% of label claim, and the subpotent prescriptions ranged in potency from 34.8% to 89.8% of label claim. Fourteen (38.9%) preparations lacked content uniformity according to the USP standard of 90%-110% potency and < 6% relative standard deviation. Of the 30 formulations packaged in jars, 12 (40%) lacked content uniformity, while of the 6 formulations packaged in tubes, 2 (33.3%) lacked content uniformity. Nine of the 12 pharmacies (75%) failed USP potency or content-uniformity specifications for at least 1 of the 3 prescription fills. For 5 of the 12 pharmacies (41.7%), the mean potency across all three prescription fills was < 90% of label claim. CONCLUSION: Patients prescribed topical 2% diltiazem for treatment of anal fissure frequently receive compounded formulations that are misbranded with respect to potency and that lack content uniformity.

A comparison of the safety of therapeutically equivalent doses of isradipine and diltiazem for treatment of essential hypertension.

We compared the safety of a new dihydropyridine calcium entry blocker, isradipine, with an equipotent dose of diltiazem in 174 mild hypertensives (diastolic blood pressure [DBP] 95 to 105 mm Hg). After appropriate washout and placebo periods, patients were randomly assigned to receive either 1.25 mg isradipine twice daily (Group I) or 40 mg diltiazem thrice daily (Group D). If DBP remained above 90 mm Hg, doses were increased to a maximum of 5 mg isradipine twice daily or 120 mg diltiazem thrice daily. Active therapy was given for a total of 12 weeks. Only 18 patients (nine from each group) did not complete the protocol. The patients were well-matched at baseline with a mean BP of 149/100 mm Hg for those who were randomized to isradipine and completed the protocol and 153/99 mm Hg for the diltiazem group. The responses to each drug were excellent with 72% of the isradipine patients and 73% of the diltiazem group having DBP less than 90 mm Hg at the completion of the study. Of the 156 patients who completed the protocol, only 18 patients (ten in Group I and eight in Group D) failed to respond. Both drugs were well-tolerated. No adverse reactions were reported by 68 percent of the patients in Group I and 65% of those in Group D. The most common side effect was headache (9.0% in Group I and 7.8% in Group D) followed by fatigue (5.2% in Group I and 3.9% in Group D). Age and race did not predict response to either agent but men responded slightly better to diltiazem than women. We conclude that isradipine and diltiazem are equally well tolerated and can be used successfully as a monotherapy to treat hypertension in a wide variety of patients.