Biomedical subjects

A Fitton

Publications and source records attributed to A Fitton.

43 records · Page 3Linked to original sources

PubMed1990

Clozapine. A review of its pharmacological properties, and therapeutic use in schizophrenia.

Clozapine, an antipsychotic agent of the dibenzodiazepine class, is characterised by relatively weak central dopaminergic activity and displays atypical pharmacological and clinical properties in relation to the classic antipsychotics. Clinical studies have shown clozapine to be effective in suppressing both the positive and negative symptoms of schizophrenia and to be associated with an extremely low incidence of extrapyramidal side effects. Clozapine has been shown to be of comparable, or on some criteria superior, therapeutic efficacy to perphenazine, levomepromazine, haloperidol and chlorpromazine in several short term comparative studies in patients with schizophrenia of predominantly acute symptomatology. Moreover, clozapine is effective in a substantial proportion (30 to 50%) of schizophrenic patients who are refractory to or intolerant of classic antipsychotic therapy. Despite its promising therapeutic potential, the relatively high incidence of clozapine-induced agranulocytosis (1 to 2% of patients) is a major factor restricting the drug's wider use in psychiatric practice. In accordance with current guidelines, clozapine therapy, performed in conjunction with close haematological monitoring, is indicated for the management of severe and chronic schizophrenia refractory to classic antipsychotic therapy, and in those unable to tolerate such therapy. In such appropriately selected patients, clozapine represents an important alternative to the classic antipsychotics.

Clozapine↗

PubMed1990

Cetirizine. A review of its pharmacological properties and clinical potential in allergic rhinitis, pollen-induced asthma, and chronic urticaria.

Cetirizine, a piperazine derivative and carboxylated metabolite of hydroxyzine, is a potent histamine H1-receptor antagonist with antiallergic properties. It has marked affinity for peripheral histamine H1-receptors and, at the standard dose of 10mg daily, lacks the CNS depressant effects of standard antihistamines. In addition, it inhibits histamine release and eosinophil chemotaxis during the secondary phase of the allergic response. Results from controlled clinical trials indicate that cetirizine is an effective and well tolerated treatment of seasonal and perennial allergic rhinitis and chronic idiopathic urticaria. Cetirizine appears to be as effective as conventional dosages of terfenadine, chlorpheniramine and hydroxyzine in relieving symptoms associated with these disorders and produces a markedly lower incidence of sedation than chlorpheniramine, hydroxyzine and several other standard antihistamines. Thus, cetirizine appears to provide a useful alternative to other 'nonsedating' antihistamines; cetirizine may also have a future role in the treatment of allergic asthma and certain forms of physical urticaria.

Animals↗

PubMedDate not supplied

The Kendrick extrication device used for pediatric spinal immobilization.

Immobilizing a child presents a unique challenge for emergency medical services (EMS) personnel in addition to those challenges faced when immobilizing an adult. Most equipment commonly carried by EMS personnel is sized for adult use and as a result does not routinely provide adequate static or dynamic immobilization of a child. In addition, children often resist immobilization and can free themselves from standard strapping techniques. These problems have led to the modification of existing equipment and the development of several pediatric-specific devices. An ideal pediatric immobilization device would be one that uses an existing piece of equipment, is of limited additional cost, is routinely used by EMS providers, could be easily modified to immobilize a child, could easily be taught to EMS providers, and provides excellent static and dynamic immobilization. The Kendrick extrication device (KED) used as the authors describe meets these goals of an ideal pediatric immobilization device.

Adult↗

PubMedDate not supplied

Intranasal salmon calcitonin. A review of its pharmacological properties and potential utility in metabolic bone disorders associated with aging.

Salmon calcitonin, a polypeptide hormone secreted by the parafollicular C cells of the thyroid gland, lowers serum calcium levels by decreasing bone resorption and renal tubular calcium reabsorption. An analgesic action, possibly mediated via beta-endorphins, is also evident. In the past, parenteral formulations of salmon calcitonin have been used in the management of metabolic bone disorders, but their routine use has been limited by the inconvenience of this route of administration and by poor tolerability. The development of an intranasal preparation of salmon calcitonin will provide a more convenient means of administering the drug. In clinical trials published to date intranasal salmon calcitonin has been effective and well tolerated in small numbers of recently postmenopausal women at risk of developing osteoporosis, and in patients with established osteoporosis, Paget's disease, or osteoporosis secondary to corticosteroid usage, multiple myeloma or ovariectomy. For periods of up to 2 years the drug reduces bone resorption and improves bone architecture, relieves pain and increases functional status. Further research is needed to confirm longer term efficacy (in particular, effects on fracture rate), optimal dosage schedules and the role of intermittent and combination treatment regimens.

Administration, Intranasal↗

PubMedDate not supplied

Terazosin. A review of its pharmacodynamic and pharmacokinetic properties, and therapeutic potential in benign prostatic hyperplasia.

Terazosin selectively antagonises alpha 1-adrenoceptor-mediated contraction of the prostate, prostatic capsule, proximal urethra and bladder base, and consequently reduces urethral pressure, bladder outlet resistance and urinary symptoms associated with symptomatic benign prostatic hyperplasia. The efficacy of terazosin is reflected in increases in peak urinary flow rate, and reductions in obstructive and irritative symptom scores compared with placebo, and reductions in residual urinary volume from baseline. Clinical improvements begin to occur within 2 weeks and have been sustained for up to 2 years. The most marked treatment effects tend to occur in patients with more severe pretreatment urinary flow abnormalities. The relatively long duration of action of terazosin, allowing once-daily administration, offers a potential clinical advantage over other alpha 1-adrenoceptor antagonists although formal compliance studies have not been reported. Terazosin is generally well tolerated, but caution is recommended at treatment initiation and when dosage adjustments are made due to an increased risk of postural hypotension and related adverse effects at these times; such a risk has also been observed with several other alpha 1-adrenoceptor antagonists. Although publication of clinical trial results with terazosin is still evolving, this drug shows promise in the treatment of patients with mild to moderate symptomatic benign prostatic hyperplasia for whom surgery is not absolutely indicated. Terazosin also shows promise as a nonsurgical treatment alternative in patients with severe symptoms who are unfit for surgery and also in those who are on long waiting lists for surgery.

Adrenergic alpha-Antagonists↗

PubMedDate not supplied

Ibopamine. A review of its pharmacodynamic and pharmacokinetic properties, and therapeutic use in congestive heart failure.

Ibopamine is an orally administered dopamine agonist which is rapidly converted to its active metabolite epinine by esterase hydrolysis. Ibopamine acts predominantly as a vasodilator and inhibitor of neuroendocrine activation in congestive heart failure, but also has mild positive inotropic effects at higher doses. The beneficial effects on cardiac and systemic haemodynamic parameters seen in short term studies have been maintained in predominantly noncomparative trials for up to 1 year, and improvements in New York Heart Association (NYHA) functional class and clinical symptoms have been observed in patients with congestive heart failure of varying severity. In double-blind studies conducted in small numbers of patients, the efficacy of ibopamine was comparable to that of digoxin, captopril, enalapril and hydrochlorothiazide. Ibopamine can successfully replace treatment with intravenous dopamine in patients with severe heart failure, and is effective and well tolerated when administered in combination with digoxin, diuretics and/or angiotensin converting enzyme (ACE) inhibitors. Ibopamine has shown no detrimental effects on renal function, few adverse effects on neurohormonal parameters and has demonstrated no significant proarrhythmic properties at therapeutic doses in patients with congestive heart failure. No adverse metabolic effects were observed during ibopamine therapy in patients with diabetes mellitus, nor did ibopamine have detrimental effects in patients with chronic obstructive pulmonary disease. While reliable evidence is required concerning effects on mortality before the role of ibopamine can be clearly defined, the drug appears to be a useful agent for combination with conventional therapies in treating patients with mild to severe congestive heart failure.

Aged↗

PubMedDate not supplied

[Central action of snake venoms on body temperature in rats].

Experiments on rats were made to study the effect on the body temperature of the rat of intracerebroventricular injection of venoms of Indian cobra, North American rattle snake, and Central Asian shchitomordnik. It was established that the rise of rectal temperature by 1.5-2.0 degrees C after 90 min was evoked by cobra venom alone. That increase in the body temperature was not prevented by pretreatment with the protein synthesis inhibitors anisomycin or cycloheximide, but was completely abolished by intraperitoneal injection of sodium salicylate. The reduction of hyperthermia was also attained with intracerebroventricular injection of the prostaglandin synthetase inhibitor valtoren as well as with subsequent (following snake venom) injections of arecoline or calcium ions.

Animals↗