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Biomedical subjects

D M Boyle

Publications and source records attributed to D M Boyle.

At least 55 records · Page 3Linked to original sources
PubMed1976

Practolol in acute myocardial infarction.

A double blind trial of practolol in coronary heart disease has been conducted for 2 years. In 298 patients with acute myocardial infarction there was no reduction in overall mortality. In a group with initial heart rate over 100 per minute mortality was significantly lowered up to 1 year. Of 484 patients with coronary heart disease treatment for 2 years did not produce a significant reduction in infarction or sudden death. Beta-adrenergic blocking drugs have been shown to reduce left ventricular work and to have an antiarrhythmic action. On these grounds they would seem theoretically to have a place in the management of acute myocardial infarction. Practolol is a cardio-selective beta-blocking agent with an intrinsic sympathomimetic action, but devoid of local anaesthetic effect. It has been found effective in post infarction arrhythmias (1). In early infarction it reduces the area of necrosis as measured by surface ST segment mapping (2).

Acute Disease↗
PubMedDate not supplied

Comparison of the plasma concentrations and efficacy of mexiletine and of a slow-release preparation of mexiletine in patients admitted to a coronary care unit.

We determined if therapeutic plasma concentrations of mexiletine (0.75-2.0 microgram/ml) could be maintained in patients admitted to a coronary care unit by twice daily dosing of a new slow-release (S.R.) formulation of mexiletine. Twenty patients, 14 with acute myocardial infarction, entered the first study and received either 250 mg conventional mexiletine at 0.8, and 14 h or 360 mg S.R. mexiletine at 0 and 12 h each day for 7 days. Blood samples were taken daily for measurement of plasma mexiletine concentrations. A continuous 24 -h ECG recording was obtained in all patients between days 3 and 6. The mean plasma concentration was greater on all days in the group that received conventional mexiletine; these differences were most marked during the first 15 h on day 1. The mean trough values on days 2-7 were in the range 0.73-1.22 microgram/ml after mexiletine and 0.63-1.17 microgram/ml after S.R. mexiletine. The incidence of ventricular arrhythmias was the same in the two groups; side effects were less common in the group receiving S.R mexiletine. Since the plasma concentration increased slowly during day 1 with S.R. mexiletine, a second study was carried out in 19 similar patients who received 360 mg S.R. mexiletine, 720 mg S.R. mexiletine, or 360 mg S.R. mexiletine and 250 mg conventional mexiletine and 12 h later 360 mg S.R. mexiletine. The plasma concentration increased most rapidly after the third regime, reaching 0.97 +/- 0.09 microgram/ml at 3 hours. These results show that therapeutic plasma concentrations of mexiletine can be maintained by the 12-hourly administration of 360 mg S.R. mexiletine, but that an additional loading dose of 250 mg mexiletine increases the plasma concentration more rapidly.

Aged↗
PubMedDate not supplied

Plasma concentrations and acceptability of mexiletine given by intramuscular injection in patients admitted to a coronary care unit.

We measured the plasma concentrations of mexiletine in patients admitted to a hospital coronary care unit after the intramuscular injection (IMI) of 200, 300, 400, and 500 mg mexiletine. Mexiletine was rapidly absorbed and concentrations greater than 0.75 microgram/ml were achieved in some patients within 5 min of the injection. The maximum mean plasma concentration increased with 200, 300, and 400 mg but was lower after 500 mg than after 400 mg. After 400 mg mexiletine, plasma concentrations greater than 0.75 microgram/ml were achieved in at least seven of nine patients from 15 min to 2 h after administration. There were no local reactions to 200, 300, or 400 mg mexiletine, but local pain and tenderness occurred in three of nine patients after 500 mg. It was decided that 400 mg mexiletine would probably be the desired dose for intramuscular administration. In 14 patients given mexiletine 400 mg by IMI followed at 2 and 12 h by 360 mg by mouth the plasma concentration was in the therapeutic range (0.75-2.0 micrograms/ml) from 15 min to 24 h in at least 64% of patients. In 12 healthy volunteers the IMI of 400 mg mexiletine increased total creatinine kinase (CK), aspartate amino-transferase, and lactate dehydrogenase enzymes but CK-MB, LDi, and LDii concentration or LDi/LDii ratio were not outside the normal range. These studies indicate that mexiletine can be safely given to patients by IMI and that therapeutic plasma concentrations are achieved.

Adult↗
PubMedDate not supplied

Vesicant extravasation: myths and realities.

PURPOSE/OBJECTIVES: To provide a comprehensive review of the literature pertinent to the phenomenon of antineoplastic vesicant extravasation within the framework of common misconceptions held by oncology nurses. DATA SOURCES: National guidelines, published articles in professional specialty journals and proceedings, and the authors' clinical experiences in the care of patients receiving vesicant agents. DATA SYNTHESIS: Antineoplastic vesicant extravasation can result in significant morbidity, severely limiting quality of life for patients with cancer. It also is a liability concern for oncology nurses. Many unanswered questions regarding extravasation exist because the phenomenon is difficult to study in humans and actual extravasation injuries are both sporadic and underreported. The incidence of extravasation from vascular access devices is unknown. Similarly, many recommended management strategies are empirically based. Misconceptions about the nature of extravasation injuries and the manner in which they should be managed contribute to poor patient outcomes and increased liability. CONCLUSIONS: The disproval of 10 myths regarding the nature and management of vesicant extravasation is an adjunctive step in the translation of existing national guidelines to workable institutional standards and appropriate professional practice. NURSING IMPLICATIONS: Oncology nurses are in a strategic position to observe the feasibility and efficacy of prevention and management guidelines established at national and local levels. Oncology nurses involved in the administration of antineoplastic vesicant agents are responsible for maintaining a current knowledge base about vesicants and for planning nursing care within the established standards of practice.

Antineoplastic Agents↗