Dose Tag's Archives
Cathartics and Enemas
Although the use of cathartics and enemas is traditional, these measures are most unlikely to reduce absorption since this usually occurs rapidly in the upper small intestine. They can only add to the misery and discomfort of the patient Efficacy in removal of drug has never been established. In one recent study, saline catharsis had no beneficial effect whatsoever on the absorption of aspirin taken with charcoal (Sketris et al. 1982).
Whole Gut Lavage
One situation where attempts to empty the bowel may be helpful is in poisoning with ’slow’ or ‘timed release’ formulations. The number of such preparations on the market is increasing and since they usually contain a much larger dose of drug than ordinary tablets, intoxication may be severe and prolonged.
Abdominal, Absorption, Aspirin, Bowel, Charcoal, Discomfort, Dose, Effect, Gastric, Ingestion, Intestine, Intoxication, Oral, Saline, Severe, Surgery, Tablet, Treatment
Haemodialysis, peritoneal dialysis, haemoperfusion, exchange transfusion and forced diuresis have all been used in attempts to increase the rate of removal of drugs and poisons. However, the amount of active drug removed is often disappointingly small, and the indications for the use of such measures is very limited.
Nevertheless, poisoned patients are often unnecessarily subjected to these potentially harmful measures, and the literature is full of anecdotal accounts of miraculous recovery attributed to such treatment (Winchester et al. 1977). Properly controlled clinical trials are difficult to carry out, and very few have been published. With the possible exception of forced alkaline diuresis for poisoning with salicylate and long acting barbiturates such as phenobarbitone, none of these methods for enhancement of drug removal has ever been shown to reduce morbidity or mortality in poisoned patients (Todd 1984).
Indeed, some studies suggest the opposite result. This is not to say that such measures are never necessary, or indeed sometimes life saving, but a more critical appraisal of their role is required.
Absorption, Acidic, Alkaline, Analytical, Bentonite, Chemical, Clinical, Dialysis, Dose, Fraction, Method, Paracetamol, Poison, Recovery, Therapeutic, Toxic, Treatment, Trial
Synopsis of Important Principles
1. Specific antidotal therapy is available for very few poisons. The mainstay of treatment of severe poisoning is intensive supportive therapy and good nursing care.
2. The great majority of poisoned patients recover with intensive supportive therapy alone, and enthusiastic claims for the success of other treatment often cannot be justified.
3. With some important exceptions, the management of poisoning is not altered by knowledge of plasma drug concentrations. There are many pitfalls in the interpretation of drug concentrations in poisoned patients, especially when nonspecific analytical methods are used.
Antidotal, Blood, Care, Circulation, Concentration, Dialysis, Diffuse, Dosage, Dose, Drug, Effect, Indication, Inhibition, Intensive, Mechanism, Metabolic, Method, Mortality, Nursing, Overdose, Pharma, Plasma, Poison, Specific, Support, Synopsis, Technique, Therapy, Toxic, Treatment, Volume
The idea that drug concentrations could be measured and used to guide therapeutic decisions was first applied to quinidine when it was used to convert the cardiac rhythm of patients with atrial fibrillation to sinus rhythm (Sokolow & Ball 1956).
Although quinidine is rarely used for this purpose today, because of the advent of DC cardioversion, this study is still almost unique because it defined a target concentration based upon both the probability of therapeutic success and of toxicity.
Data, Distribution, Dose, Drug, Effect, Foundation, Monitoring, Rational, Science, Selection, Sensitivity, Studies, Therapeutic, Toxicity, Value
Therapeutic drug monitoring is based upon the collaboration between a health care provider (clinician, pharmacist, nurse) responsible for making quantitative and qualitative decisions about drug treatment and the clinical laboratory providing analytical services for the measurement of drug concentrations. The information provided by a drug concentration measurement is generally greater than for other substances measured by the laboratory.
This is because, unlike say sodium or glucose, the intake of a drug is quite well known and the processes of distribution and elimination are usually very simple and not under the control of a multitude of homeostatic controlling reflexes.
Analytical, Clinical, Collaboration, Diagnose, Dosage, Dose, Drug, Figures, Forecasting, Glucose, Interval, Laboratory, Measurement, Multitude, Precision, Provider, Quantitative, Rational, Reference, Serum, Substance, Substitute, Therapeutic, Treatment, Value
