Biomedical subjects
A J Ellsworth
Publications and source records attributed to A J Ellsworth.
Treatment of a patient with an undefined hypercoagulable state with long-term low-molecular-weight heparin.
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Community patterns of transdermal nicotine use and provider counseling.
OBJECTIVES: To examine how transdermal nicotine is prescribed and used in the general population, and to identify variables associated with successful smoking cessation in patch users. DESIGN: Retrospective cohort survey. SETTING: A random sample of 70 pharmacies in King County, Washington, were asked to participate. Of those, 33 pharmacies ran computer searches of prescriptions for any nicotine patch dispensed between July 1 and December 31, 1992. A total of 1,087 individuals receiving patches were identified. PATIENTS: At least eight months after the nicotine patches were purchased, 972 subjects received questionnaires by mail from the participating pharmacies. The survey was completed by 433 (45.2%) subjects. MAIN RESULTS: Eighty percent of the respondents requested patches from a provider, 81% of whom were primary care physicians. Ninety-six percent used the patch, 45% smoked while using the patch, and 37% reported having quit smoking. Smoking cessation was associated with daily patch application (odds ratio [OR] 1.6, 95% confidence interval [CI] 1.2-2.2), abstinence during patch use (OR 7.7, 95% CI 4.8-12.5), and a longer duration of patch use (p = 0.001). A score reflecting counseling intensity by the provider was associated with abstinence while using patches and smoking cessation (chi 2 for tread = 0.01 and 0.04, respectively). CONCLUSIONS: Most nicotine patch users request treatment from a primary care physician, suggesting motivation to quit. Almost half continue to smoke while using the patch, a behavior that appears related to a lower level of counseling and an inability to quit. Increasing counseling may positively impact nicotine-patch-assisted smoking cessation in the general population.
Randomized clinical trials in single patients during a 2-year period.
OBJECTIVE: To describe the feasibility of a single patient trial (SPT) service and study the influence of formal SPTs on therapeutic precision. DESIGN: Descriptive and evaluate study of SPTs. All planned trials were double-blind, randomized, multiple crossover trials. Other key features of individual trials were random assignment of order and assessment of predetermined explicit outcomes. Patients and physicians rated level of confidence in treatment before and after the SPT on visual analog scales. SETTING: Two-year experience (September 1988 to September 1990) of an SPT trial referral service available to physicians in an academic medical center. OUTCOME MEASURES: The number of planned and completed SPTs; proportion of completed trials yielding definitive answers; patient- and physician-rated levels of confidence in treatment pre- and post-SPT; time-motion studies to estimate resource consumption (costs) for selected SPTs. RESULTS: Of 34 completed trials, 17 were judged to give definitive results whereas 17 showed trends only. Results favored active treatment in 16 trials that led to treatment being continued (nine patients) or started (seven patients). Treatment was discontinued (seven patients) or not started (11 patients) based on 18 trial results that demonstrated active treatment was ineffective (seven), harmful (two), or apparently equivalent (nine). Most patients (65%) reported no change in their already high level of confidence in therapy as a result of trials, whereas physicians' confidence levels in therapy either increased or decreased post-SPT depending on the direction of trial results. Patients consistently rated the SPT service as extremely useful. Time-motion estimates indicate that 16.75 staff hours were spent per trial leading to a direct cost estimate of approximately $450 to $500 per trial. CONCLUSION: We conclude that an SPT service is feasible, trial costs compare favorably with other conventional services, and clinicians appear to gain confidence and precision from SPTs. When patients or clinicians are uncertain about the value (including the possibility of side effects) of treatment for symptomatic chronic diseases, we believe an SPT can be offered to a patient and will likely yield results that will effect subsequent treatment.
Amiodarone-clonazepam interaction.
OBJECTIVE: To describe a potential drug interaction between amiodarone and clonazepam. CASE SUMMARY: A 78-year-old man with a history of congestive heart failure and coronary artery disease began taking amiodarone to suppress sustained ventricular tachycardia. Following the development of restless leg syndrome, therapy with clonazepam 0.5 mg qhs was initiated. Subsequently, the patient demonstrated signs and symptoms of benzodiazepine toxicity, which cleared following the discontinuation of clonazepam. DISCUSSION: Amiodarone is a Class III antiarrhythmic with an adverse-effect profile involving many different organ systems. It also has been shown to inhibit the metabolism of drugs cleared by oxidative microsomal enzymes. Clonazepam undergoes extensive hepatic metabolism, primarily by reduction and acetylation, and is therefore susceptible to altered disposition during concomitant administration of agents that inhibit hepatic microsomal enzymes. Hypothyroidism, occurring in up to 11 percent of patients treated with amiodarone, can also alter drug metabolism and sensitize the central nervous system, thus increasing the potential for toxicity. It is likely that a combination of these factors was responsible for the symptoms described in this patient. CONCLUSIONS: The complex pharmacologic profile of amiodarone and its effects on multiple organ systems necessitates close patient monitoring during concurrent administration of medications such as clonazepam, which are cleared by oxidative metabolism.
Acetazolamide or dexamethasone use versus placebo to prevent acute mountain sickness on Mount Rainier.
Eighteen climbers actively ascended Mount Rainier (elevation 4,392 m) twice during a randomized, double-blind, concurrent, placebo-controlled, crossover trial comparing the use of acetazolamide, 250 mg, dexamethasone, 4 mg, and placebo every 8 hours as prophylaxis for acute mountain sickness. Each subject was randomly assigned to receive placebo during one ascent and one of the active medications during the other ascent. Assessment of acute mountain sickness was performed using the Environmental Symptoms Questionnaire and a clinical interview. At the summit or high point attained above base camp, the use of dexamethasone significantly reduced the incidence of acute mountain sickness and the severity of symptoms. Cerebral and respiratory symptom severity scores for subjects receiving dexamethasone (0.26 +/- 0.16 and 0.20 +/- 0.19, respectively) were significantly lower than similar scores for both acetazolamide (0.80 +/- 0.80 and 1.20 +/- 1.05; P = 0.25) and placebo (1.11 +/- 1.02 and 1.45 +/- 1.27; P = .025). Neither the use of dexamethasone nor that of acetazolamide measurably affected other physical or mental aspects. Compared with placebo, dexamethasone appears to be effective for prophylaxis of symptoms associated with acute mountain sickness accompanying rapid ascent. The precise role of dexamethasone for the prophylaxis of acute mountain sickness is not known, but it can be considered for persons without contraindications who are intolerant of acetazolamide, for whom acetazolamide is ineffective, or who must make forced, rapid ascent to high altitude for a short period of time with a guaranteed retreat route.
Prospective comparison of patient tolerance to enteric-coated vs nonenteric-coated erythromycin.
Erythromycin base and its salts are frequently used in clinical practice. The most frequent side effects of oral erythromycin preparations are gastrointestinal. Various salts and enteric coatings have been developed without adequate comparison in regard to gastrointestinal side effects. The overall incidence of gastrointestinal side effects (abdominal pain and cramps, nausea, vomiting, diarrhea, and gas) of two common erythromycin base formulations, Erythromycin Base Filmtab (Abbott), a nonenteric-coated base tablet, and Eryc (Parke-Davis), a pelletized, encapsulated, enteric-coated base capsule, were compared in 368 adults at two dosage levels (1 g/d and 2 g/d). Minimal differences were found when target symptoms were compared by preparation coating. In contrast, subjects receiving erythromycin at the 2-g/d dosage level reported higher incidence rates for each of the target symptoms, regardless of product coating, than did those patients treated at the 1-g/d dosage level. Enteric coating of erythromycin base offers little protection from the common dose-related gastrointestinal adverse effects of oral erythromycin.
Oral contraceptives.
Management of oral contraception requires an understanding of the relationships between the method's effectiveness, noncontraceptive benefits, and hormonal adverse effects. The new multiphasic combinations or OCs containing 35 micrograms of ethinyl estradiol and 0.5-1.0 mg of norethindrone or equivalent result in a maximum combination of efficacy and safety for the patient with minimal annoying problems for the patient and the prescriber. Patient education regarding early warning symptoms of adverse effects, breakthrough bleeding, and lack of withdrawal bleeding adds an additional margin of safety and reduces patient questions and uncertainties.
Disopyramide and N-monodesalkyl disopyramide in serum and breast milk.
Maternal serum and breast milk were obtained to determine the concentration of disopyramide (DP) and its metabolite N-monodesalkyl disopyramide (NMD) from a woman requiring antidysrhythmic drug therapy. Infant serum and urine were also obtained for drug concentrations. DP 450 mg tid resulted in peak maternal serum concentrations of 4.0 micrograms/mL and 2.2 micrograms/mL for DP and NMD, respectively. Breast milk concentrations averaged 1.06 and 6.24 times the serum levels for DP and NMD, respectively. No DP was measurable in the infant's serum except for cord blood, which contained 0.7 micrograms/mL DP, 26 percent of simultaneous maternal concentration, and 0.9 micrograms/mL NMD, which represented 43 percent of the maternal concentration. Infant urine collected over an eight-hour period contained 3.3 micrograms/mL of DP and 3.7 micrograms/mL of NMD.
A randomized trial of dexamethasone and acetazolamide for acute mountain sickness prophylaxis.
Forty-seven climbers participated in a double-blind, randomized trial comparing acetazolamide 250 mg, dexamethasone 4 mg, and placebo every eight hours as prophylaxis for acute mountain sickness during rapid, active ascent of Mount Rainier (elevation 4,392 m). Forty-two subjects (89.4 percent) achieved the summit in an average of 34.5 hours after leaving sea level. At the summit or high point attained above base camp, the group taking dexamethasone reported less headache, tiredness, dizziness, nausea, clumsiness, and a greater sense of feeling refreshed (p less than or equal to 0.05). In addition, they reported fewer problems of runny nose and feeling cold, symptoms unrelated to acute mountain sickness. The acetazolamide group differed significantly (p less than or equal to 0.05) from other groups at low elevations (1,300 to 1,600 m), in that they experienced more feelings of nausea and tiredness, and they were less refreshed. These drug side effects probably obscured the previously established prophylactic effects of acetazolamide for acute mountain sickness. Separate analysis of an acetazolamide subgroup that did not experience side effects at low elevations revealed a prophylactic effect of acetazolamide similar in magnitude to the dexamethasone effect but lacking the euphoric effects of dexamethasone. This study demonstrates that prophylaxis with dexamethasone can reduce the symptoms associated with acute mountain sickness during active ascent and that acetazolamide can cause side effects that may limit its effectiveness as prophylaxis against the disease.
Zomepirac, interstitial nephritis, and renal failure.
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Treatment of atopic dermatitis with antihistamines: lessons from a single-patient, randomized clinical trial.
BACKGROUND: Single-patient randomized clinical trials (RCTs) can be utilized to maintain methodologic precision in the analysis of treatment effect in individual patients. We describe the results of a single-patient RCT in a patient with atopic dermatitis and review practical considerations regarding the use of antihistamines. METHODS: Using double-blind, crossover techniques, the patient was randomly allocated to four 2-week treatment periods with the following regimens: chlorpheniramine, 8 mg twice daily; chlorpheniramine, 12 mg twice daily; terfenadine, 120 mg twice daily; and placebo (phase 1). The drug that produced superior results from phase 1 (chlorpheniramine, 8 mg) was subsequently compared with astemizole, 10 mg/d, during phase 2, consisting of four 4-week, double-blind, crossover trial periods with random allocation of study drugs. Daily symptom scores, as well as end of treatment period summary impressions by patient and investigator, were analyzed. RESULTS: In both phases, chlorpheniramine produced the most noticeable positive therapeutic effect on the patient's mild but most disturbing symptoms (pruritus and eye irritation) associated with atopic dermatitis. Drowsiness was reported with chlorpheniramine. Tolerance to this side effect, however, developed quickly. CONCLUSIONS: A single-patient RCT with different antihistamines in a patient with chronic atopic dermatitis was a useful tool in achieving a favorable balance among efficacy, toxicity, and cost of therapy.