Contraindicated medications dispensed with cisapride: temporal trends in relation to the sending of 'Dear Doctor' letters.

PURPOSE: 'Dear Doctor' letters alert the prescribing community of drug labeling changes that contain new contraindications, warnings, adverse reactions, and precautions. There has been little assessment of the impact of these letters. We quantified the impact of two 'Dear Doctor' letters concerning interactions between cisapride and a series of drugs. A letter in 1995 described a risk of prolonged QT intervals and serious ventricular arrhythmia in patients who received macrolide antibiotics and imidazole antifungals in conjunction with cisapride. A June 1998 letter that expanded the list of contraindicated comedications had wider distribution than an earlier one, was accompanied by substantial Internet and media coverage, and was complemented by an effort to inform large pharmacy dispensing information organizations of the warnings against concurrent use of the named drugs. METHODS: Health plan members with one or more outpatient pharmacy claims for cisapride during the period 1 January 1995 through 31 May 1999 were identified among members of a large New England health insurer. A retrospective review of concurrent and nearly concurrent dispensings of cisapride and contraindicated comedications was undertaken in the automated pharmacy claims data using both graphical and statistical time-series analysis. We tabulated by month the fraction of cisapride dispensings that occurred in close temporal relation to dispensings of contraindicated comedications. Codispensings that occurred on the same day were taken as the most direct measure of prescriber responsiveness to the letters. Codispensings that occurred in windows of plus or minus 2 weeks (29 day window) and plus or minus 4 weeks (57 day window) were taken as measures of possible simultaneous consumption. Among overlapping dispensings, we counted the proportion dispensed by the same pharmacy. Time series regression analysis of secular, seasonal, and step-effects was conducted. RESULTS: There was a steady decline in codispensing of cisapride and contraindicated medicines, and a pronounced seasonal effect, arising principally from the seasonal use of macrolide antibiotics. Against this background, the isolated Dear Doctor letter of October 1995 had no discernible effect on prescribing practices. The 1998 letter and surrounding activity, by contrast, were followed by a 66% decline in same-day dispensings and a smaller, but still pronounced decline in dispensings in the wider time windows. For most codispensings of contraindicated medications with cisapride, both medications came from the same pharmacy. CONCLUSIONS: Publicity and direct intervention with dispensing pharmacies may be an important supplement to Dear Doctor letters when the goal is to eliminate the codispensing of drugs that should not be taken together.

Ketoconazole 2% shampoo in the treatment of tinea versicolor: a multicenter, randomized, double-blind, placebo-controlled trial.

BACKGROUND: Tinea versicolor is a common superficial fungal infection caused by a lipophilic yeast. This chronically recurring opportunistic infection is especially prevalent in tropical and semitropical regions. The topical short-term application of ketoconazole 2% shampoo may provide effective and safe therapy for tinea versicolor. OBJECTIVE: The purpose of this study was to evaluate the efficacy and safety of a single application (1 day) versus three daily applications (3 days) of ketoconazole 2% shampoo versus placebo shampoo in the treatment of mycologically confirmed tinea versicolor. METHODS: Three hundred twelve patients were included in the primary analyses for this 31-day study. Global evaluation scores were measured on days 10 and 31 with a 5-point scale (1 = healed to 5 = worsening), and a cellophane tape test was done at baseline and days 3, 10, and 31. Efficacy was assessed by clinical response, defined as both a global evaluation score of 1 (healed) and a negative cellophane tape test on day 31. Signs and symptoms of tinea versicolor (scaling, itching, erythema, hypopigmentation, hyperpigmentation) also were evaluated at baseline, day 10, and day 31 with a 4-point scale (0 = absent to 3 = severe). RESULTS: Both regimens of ketoconazole shampoo were significantly (P < .001) more effective than placebo for rate of clinical response, global evaluation scores, and mycologic outcomes (cellophane tape test). The clinical response rates at day 31 were 73%, 69%, and 5% for the 3-day ketoconazole, 1-day ketoconazole, and placebo groups, respectively. The difference in the efficacy of the two ketoconazole treatment regimens was not statistically significant. There were no significant differences between any of the treatment groups in the number of patients who experienced adverse events. No serious adverse events occurred and no patient withdrew from the trial prematurely because of an adverse event. CONCLUSION: Ketoconazole 2% shampoo, used as a single application or daily for 3 days, is safe and highly effective in the treatment of tinea versicolor.

Effect of cetamolol on epinephrine-induced hypokalemia.

The effect of cetamolol (an investigational cardioselective beta blocker with intrinsic sympathomimetic activity) on the hypokalemic response to epinephrine infusions in normal subjects was evaluated and compared with placebo and two other beta-adrenergic blocking drugs. After two daily doses of cetamolol 15 mg, atenolol (a cardioselective beta blocker) 50 mg; a long-acting propranolol preparation (a nonselective beta blocker) 80 mg; or placebo, 12 men (mean age, 26.7 years) were infused with epinephrine. The resulting average plasma epinephrine level was 1123 pg/mL, whereas average baseline serum potassium levels for the four treatment groups ranged from 3.94 to 4.07 mEq/L. Epinephrine-induced hypokalemia occurred in the placebo group (maximum potassium decrease of 1.00 mEq/L) and in the atenolol group (maximum potassium decrease of 0.59 mEq/L); potassium levels did not decrease but rose slightly in subjects receiving cetamolol or propranolol. Subjects treated with placebo or atenolol also demonstrated statistically significant prolongation of the QTc interval (0.039 seconds with placebo; 0.023 seconds with atenolol) and frequently developed T-wave flattening and U-wave appearance. After pretreatment with cetamolol or propranolol, however, the QTc interval was unaffected, T-wave abnormalities did not occur, and U waves appeared only rarely. The results of this study indicate that cetamolol blocks epinephrine-induced hypokalemia and associated electrocardiographic changes.

Cardioselectivity of cetamolol compared with atenolol and nadolol.

The selectivity of the beta-adrenoceptor blockade produced by single oral doses of cetamolol, atenolol, and nadolol was compared in normal male subjects. Study 1 established the dose at which each drug provides equivalent beta-1 blockade. Beta-1 blockade was estimated using the degree of inhibition of the increased heart rate (HR) response to graded exercise. Cetamolol (30 mg), atenolol (100 mg), and nadolol (80 mg) all attenuated the HR response to a comparable extent. This result established that the dose ratio of cetamolol:atenolol:nadolol of 1.00:3.33:2.67 provides equipotent beta-1 blockade. This ratio of doses was used in Studies 2 and 3 to evaluate the antagonism of beta-2-mediated responses to titrated doses of intravenous isoproterenol (ISO) by low and high doses of each drug. Beta-2 blockade was assessed using the attenuation of ISO-induced reductions in diastolic blood pressure (DBP) in Study 2 and ISO-induced increases in specific airway conductance (sGAW) in Study 3. For within drug comparisons, antagonism of the HR increase induced by ISO (a response mediated by both beta-1 and beta-2 receptors) was also examined. Treatments included cetamolol (15 and 60 mg), atenolol (50 and 200 mg), and nadolol (40 and 160 mg in Study 2; 40 mg only in Study 3). All drugs tested suppressed the HR, DBP, and sGAW responses to ISO, and this blockade was dose dependent. Cetamolol and nadolol produced approximately equipotent beta-1 blockade, whereas cetamolol at both doses produced a less potent beta-2 blockade. Atenolol antagonized ISO effects on all parameters less than either cetamolol or nadolol. Quantitative cardioselectivity indices revealed that cetamolol 60 mg was the most cardioselective and nadolol 40 mg the least. Data from the three studies demonstrate that cetamolol is cardioselective relative to nadolol and that, in contrast to atenolol, cardioselectivity appears to increase at the higher dose.

Pharmacokinetics of cetamolol in hypertensive patients with normal and compromised renal function.

The efficacy, safety, and pharmacokinetic parameters of a 30-mg oral dose of cetamolol hydrochloride (Betacor), a new synthetic cardioselective beta-adrenoceptor antagonist, with intrinsic sympathomimetic activity, were evaluated by studying 32 hypertensive patients with normal renal function or different degrees of renal impairment. After administration of cetamolol, serial blood and urine sample collections, as well as vital sign determinations for the next 48 hours, were performed in all patients (with the exception of urine collection, which was not possible in hemodialysis patients). Results indicate that cetamolol's pharmacokinetic parameters are significantly changed in patients who have moderate or severe renal impairment. Specifically, as the severity of renal impairment increased, the maximum serum concentration (Cmax) and the area under the serum concentration-time curve (AUC) increased, whereas the renal clearance (CLR), urinary excretion, and total body clearance (CL) decreased. Additionally, significant direct or inverse correlations for AUC, CL, CLR, and urinary excretion with creatinine clearance (CLCR) were demonstrated. In the subjects with mild renal impairment, the trends toward changes in the cetamolol pharmacokinetic parameters were evident, though small and not statistically significant. Although anuric, patients on hemodialysis still retained the ability metabolically to clear cetamolol at a rate of about one-third of that found in normal subjects. Reductions in blood pressure and heart rate also were found to be greater and more prolonged as the severity of renal impairment increased. There were no adverse drug or toxic effects noted in any of the study patients. Based on these findings, dosing recommendations are suggested for patients who have compromised renal function because of the effects of renal function on the pharmacokinetics of cetamolol.

Antihypertensive efficacy of cetamolol: a dose-titrated study.

This double-blind, placebo-controlled, randomized multicenter study evaluated the antihypertensive efficacy and safety of cetamolol hydrochloride in 108 patients diagnosed as having mild to moderate hypertension. After a placebo lead-in period, patients received either cetamolol 5-10-15 mg/d (low dose), cetamolol 15-25-50 mg/d (high dose), or placebo, once daily for four weeks. Patients began at the lowest dose and were titrated to higher doses based on the first two assessments of diastolic blood pressure and heart rate, which were conducted each week after double-blind treatment was dispensed. After four weeks of treatment 82.4%, 81.3%, and 93.3% of the low-dose group, high-dose group, and placebo group, respectively, were titrated to the maximum dose level. After four weeks of treatment and 24 hours since the patient's last dose, both cetamolol groups showed a significantly greater (P less than or equal to .05) reduction in supine systolic/diastolic blood pressure (-18.1 +/- 2.3/-9.2 +/- 1.5 mm Hg [low dose] and -17.3 +/- 2.3/-8.3 +/- 1.6 mm Hg [high dose]) than the placebo group (-9.9 +/- 2.5/-3.5 +/- 1.7 mm Hg). In general, the changes in standing (stabilized) systolic and diastolic blood pressure were similar to those seen in supine measurements. Significantly more patients receiving cetamolol than those receiving placebo showed a "good response" (a decrease in diastolic blood pressure of 10 mm Hg or more or measuring less than 90 mm Hg with a decrease of at least 4 mm Hg).(ABSTRACT TRUNCATED AT 250 WORDS)

Contrasting splenic mechanisms in the blood clearance of red blood cells and colloidal particles.

We have studied the blood clearance and organ uptake of colloidal particles and of antibody-coated and chemically treated Na2 51Cr O4-labeled erythrocytes (RBC) in mice. Hepatic and splenic uptake of both colloidal particles and autologous RBC coated with rabbit antibody were reduced significantly following pretreatment of animals with cortisone acetate. Hepatic removal of RBC previously treated in vitro with N-ethyl-maleimide (NEM) or phenylhydrazine-HCl (PHZ) was similarly depressed by pretreatment with cortisone. In contrast, the splenic uptake of NEM- and PHZ-altered erythrocytes was unaffected by cortisone. Scanning and transmission electron microscopic examination of perfused spleens from PHZ-injected animals demonstrated extensive mechanical trapping of Heinz body-containing RBC in sinus wall apertures, whereas little erythrophagocytosis was observed. These studies suggested that, while clearance of inert particulate matter and of antibody-coated RBC from the blood occurred primarily by a cortisone-suppressible, presumably phagocytic process in the spleen, chemically altered RBC were removed primarily by a cortisone-insensitive filtration process in the splenic microvasculature.