Biomedical subjects

A Fitton

Publications and source records attributed to A Fitton.

At least 19 recordsLinked to original sources

PubMed1997

Certified first responder: a comprehensive model for pediatric training.

The purpose of this document is to present a general approach to educating the First Responder in Emergency Pediatric Care. The First Responder is especially important in the emergency care of the sick or injured child. The majority of mortality and morbidity associated with pediatric emergencies is a result of airway and ventilatory compromise. In addition, most airway and ventilation problems can be corrected with only basic life support interventions that are within the scope of practice of the First Responder. As a result, it is of paramount importance to assure that the First Responder is adequately trained in the initial care of the pediatric patient. This document will review some of the key objectives and topics which the First Responder needs to understand in order to adequately care for children until further emergency care arrives. Templates for lesson plans and suggested activities for training the First Responder are also presented.

Certification↗

PubMed1996

Pantoprazole. A review of its pharmacological properties and therapeutic use in acid-related disorders.

Pantoprazole is an irreversible proton pump inhibitor which, at the therapeutic dose of 40mg, effectively reduces gastric acid secretion. In controlled clinical trials, pantoprazole (40mg once daily) has proved superior to ranitidine (300mg once daily or 150mg twice daily) and equivalent to omeprazole (20mg once daily) in the short term (< or = 8 weeks) treatment of acute peptic ulcer and reflux oesophagitis. Gastric and duodenal ulcer healing proceeded significantly faster with pantoprazole than with ranitidine, and at similar rates with pantoprazole and omeprazole. The time course of gastric ulcer pain relief was similar with pantoprazole, ranitidine and omeprazole, whereas duodenal ulcer pain was alleviated more rapidly with pantoprazole than ranitidine. Pantoprazole (40mg once daily) showed superior efficacy to famotidine (40mg once daily) in ulcer healing and pain relief after 2 weeks in patients with duodenal ulcer in a large multicentre nonblinded study. In mild to moderate acute reflux oesophagitis, significantly greater healing was obtained with pantoprazole than with ranitidine and famotidine, whereas similar healing rates were seen with pantoprazole and omeprazole. Pantoprazole showed a significant advantage over ranitidine in relieving symptoms of heartburn and acid regurgitation. Reflux symptoms were similarly alleviated by pantoprazole and omeprazole. Preliminary results indicate that triple therapy with pantoprazole, clarithromycin and either metronidazole or tinidazole is effective in the treatment of Helicobacter pylori-associated disease; however, these findings require confirmation in large well-controlled studies. Pantoprazole appears to be well tolerated during short term oral administration, with diarrhoea (1.5%), headache (1.3%), dizziness (0.7%), pruritus (0.5%) and skin rash (0.4%) representing the most frequent adverse events. The drug has lower affinity than omeprazole or lansoprazole for hepatic cytochrome P450 and shows no clinically relevant pharmacokinetic or pharmacodynamic interactions at therapeutic doses with a wide range of drug substrates for this isoenzyme system. In conclusion, pantoprazole is superior to ranitidine and as effective as omeprazole in the short term treatment of peptic ulcer and reflux oesophagitis, has shown efficacy when combined with antibacterial agents in H. pylori eradication, is apparently well tolerated and offers the potential advantage of minimal risk of drug interaction.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMed1996

Lornoxicam. A review of its pharmacology and therapeutic potential in the management of painful and inflammatory conditions.

Lornoxicam (chlortenoxicam), a new nonsteroidal anti-inflammatory drug (NSAID) of the oxicam class with analgesic, anti-inflammatory and antipyretic properties, is available in oral and parenteral formulations. It is distinguished from established oxicams by a relatively short elimination half-life (3 to 5 hours), which may be advantageous from a tolerability standpoint. Data from preliminary clinical trials suggest that lornoxicam is as effective as the opioid analgesics morphine, pethidine (meperidine) and tramadol in relieving postoperative pain following gynaecological or orthopaedic surgery, and as effective as other NSAIDs after oral surgery. Lornoxicam was also as effective as other NSAIDs in relieving symptoms of osteoarthritis, rheumatoid arthritis, ankylosing spondylitis, acute sciatica and low back pain. Lornoxicam has a tolerability profile characteristic of an NSAID, with gastrointestinal disturbances being the most common adverse events. Limited clinical experience to date suggests that, as with a number of other NSAIDs, lornoxicam may provide a better-tolerated alternative or adjuvant to opioid analgesics for the management of moderate to severe pain. It has also demonstrated potential as an alternative to other NSAIDs for the management of arthritis and other painful and inflammatory conditions. These preliminary findings require confirmation in further comparative and long term studies.

Absorption↗

PubMed1995

Oxybutynin. A review of its pharmacodynamic and pharmacokinetic properties, and its therapeutic use in detrusor instability.

Oxybutynin possesses anticholinergic and spasmolytic properties, which together form the basis for its use as a therapeutic option in patients with overactive detrusor function--either idiopathic detrusor instability (DI) or detrusor hyperreflexia. Of the symptoms of detrusor overactivity, urge incontinence is often the most distressing to the patient. Urge incontinence and other subjective parameters (urinary frequency, urgency) improve in tandem with objective (cystometric) measures (maximum detrusor pressure during filling, volume at first desire to void, maximum bladder capacity) in ambulatory, including elderly, patients treated with oxybutynin. However, on the basis of results of limited investigations, the drug appears ineffective in elderly institutionalised individuals. Relative to other anticholinergic drugs, oxybutynin appears at least as effective as propantheline and similar in efficacy to propiverine in small trials, although these results are not definitive. Further investigation of intravesical oxybutynin may lead to this route becoming an option in patients with pre-existing catheters. Adverse effects--dry mouth, constipation, blurred vision--related to the anticholinergic activity of oxybutynin occur frequently and can be sufficiently troublesome to necessitate treatment discontinuation in up to 25% of patients, depending on the dosage. Increases in residual urine volume suggesting urinary retention (undesirable in patients with idiopathic DI), also can develop in some oxybutynin recipients. In summary, oxybutynin is one of the few drugs proven to be beneficial in some patients with overactive detrusor function. Despite the occurrence of unwanted anticholinergic effects in many patients, and apparent lack of efficacy in the elderly institutionalised population, oxybutynin should be considered for the drug of first choice in patients with detrusor overactivity, including the elderly ambulatory population, when pharmacological therapy is indicated.

Animals↗

PubMed1995

Torasemide. An update of its pharmacological properties and therapeutic efficacy.

The pharmacological properties and therapeutic use of the high-ceiling loop diuretic torasemide (torsemide) were previously reviewed in Drugs in 1991, the following being a re-examination of the role of the drug in the light of data that have subsequently become available (particularly in the management of oedematous disorders). Torasemide produces a more prolonged water and electrolyte excretion than equipotent diuretic doses of furosemide (frusemide), but does not increase kaliuresis to the same extent. Dosages of torasemide of 2.5 to 5 mg/day do not affect plasma renin activity or aldosterone release to a clinically significant extent, although torasemide 20mg increases plasma renin levels, angiotensin II activity and urinary dopamine and prostaglandin E excretion. Studies published since the previous review have confirmed the efficacy of low dosages of torasemide (2.5 to 5 mg/day) in the treatment of hypertension, and have shown it to be effective when administered orally at a dosage of 5 to 20 mg/day in the management of congestive heart failure. Dosages of up to 400 mg/day increased urinary volume excretion and natriuresis in patients with chronic renal failure. Bodyweight and peripheral oedema were reduced by torasemide 10 to 200 mg/day as monotherapy, and 5 to 20 mg/day when coadministered with spironolactone, in patients with nephrotic syndrome. Dosages of 10 to 40 mg/day, either as monotherapy or in conjunction with an aldosterone antagonist, reduced ascites, oedema and bodyweight in patients with hydropically decompensated liver failure. Adverse effects due to torasemide are usually mild and transient in nature. No evidence of ototoxicity has been demonstrated in humans, and torasemide does not appear to affect blood glucose levels, serum uric acid concentrations, or serum potassium levels at dosages below 5 mg/day. Thus, additional evidence has accumulated for the clinical efficacy of torasemide in the management of mild to moderate essential hypertension and oedematous conditions which require diuretic therapy. Further studies are now required to confirm the long term efficacy and tolerability of torasemide, and to investigate the place of the drug in therapy relative to cardiovascular agents other than furosemide and the thiazide diuretics.

Age Factors↗

PubMed1995

Cabergoline. A review of its pharmacological properties and therapeutic potential in the treatment of hyperprolactinaemia and inhibition of lactation.

Cabergoline is a synthetic ergoline which shows high specificity and affinity for the dopamine D2 receptor. It is a potent and very long-acting inhibitor of prolactin secretion. Prolactin-lowering effects occur rapidly and, after a single dose, were evident at the end of follow up (21 days) in puerperal women, and up to 14 days in patients with hyperprolactinaemia. In the only comparative study to date, cabergoline 0.5 to 1.0 mg twice weekly was more effective than bromocriptine 2.5 to 5.0 mg twice daily in the treatment of hyperprolactinaemic amenorrhoea, restoring ovulatory cycles in 72% of women and normalising plasma prolactin levels in 83%, compared with 52 and 58%, respectively, for bromocriptine. In the prevention of puerperal lactation, a single dose of cabergoline 1.0mg was as effective as bromocriptine 2.5mg twice daily for 14 days. A significantly lower incidence of rebound lactation in the third postpartum week was seen with cabergoline. Unpublished data suggest cabergoline 0.25mg twice daily for 2 days is effective in suppressing established puerperal lactation in about 85% of women. Nausea, vomiting, headache and dizziness are characteristic adverse events of the dopaminergic ergot derivatives. Cabergoline appears to be better tolerated than bromocriptine in both patients with hyperprolactinaemia and postpartum women. Most patients intolerant of other ergot derivatives can tolerate cabergoline. Bromocriptine use in the puerperium has been associated with an increased risk of serious thromboembolic events. However, there are no such reports with cabergoline and whether these events will become associated with other dopaminergic agents is unknown. The teratogenic potential of cabergoline has not been extensively investigated in humans. Ten congenital abnormalities have been reported in 199 cabergoline-associated pregnancies. Although there is no pattern to these abnormalities, the limited experience with cabergoline in pregnancy means the drug cannot be considered as a first-line therapy for the treatment of infertility associated with hyperprolactinaemia. At this stage of its development, cabergoline will prove useful in patients with hyperprolactinaemia who have failed treatment with, or are intolerant of, other dopamine agonists such as bromocriptine. If drug treatment is required for the prevention or suppression of puerperal lactation, cabergoline offers significant advantages over bromocriptine and should become the drug treatment of first choice for this indication.

Administration, Oral↗

PubMed1995

Lamotrigine. An update of its pharmacology and therapeutic use in epilepsy.

Lamotrigine is an antiepileptic agent which blocks voltage-dependent sodium channels, thereby preventing excitatory neurotransmitter release. Clinical evidence indicates that lamotrigine is effective against partial and secondarily generalised tonic-clonic seizures, as well as idiopathic (primary) generalised epilepsy. As monotherapy, lamotrigine 100 to 300 mg/day has similar medium term (30 to 48 weeks) efficacy to carbamazepine 300 to 1400 mg/day and phenytoin 300 mg/day against partial onset seizures and idiopathic generalised tonic-clonic seizures in adults with newly diagnosed epilepsy, and appears to be better tolerated than the older agents. As adjunctive therapy, lamotrigine (50 to 500 mg/day) has shown efficacy in short term ( < or = 6-months) placebo-controlled studies in adults with refractory partial epilepsy, reducing total seizure frequency (by < or = 60%) and producing improvement ( > or = 50% reduction in seizure frequency) in < or = 67% of patients. Both simple and complex partial seizures and secondarily generalised tonic-clonic seizures are reduced by lamotrigine, with generalised seizures (particularly absence seizures, atonic seizures and Lennox-Gastaut syndrome) tending to be more responsive than partial seizures. This reduction in seizure frequency is sustained on long term ( < or = 3 years) therapy and is reportedly accompanied by an improvement in psychological well-being. In children with refractory multiple seizure types, lamotrigine ( < or = 15 mg/kg/day; 400 mg/day) has proved effective as add-on therapy, with approximately equal to 40% of patients showing > or = 50% reductions in seizure frequency and approximately equal to 10 % achieving abolition of seizures after 3 months' treatment. Generalised seizures, including atypical and typical absence seizures, atonic and tonic seizures and Lennox-Gastaut syndrome are most responsive. The most common adverse events associated with lamotrigine are primarily neurological, gastrointestinal and dermatological. Maculopapular or erythematous skin rash, occasionally severe, occurs in approximately equal to 10% of patients and is the most common cause of treatment withdrawal. The risk of rash can, however, be minimised through adoption of a low, slow dosage titration schedule on initiating therapy. As monotherapy, lamotrigine produces less drowsiness than carbamazepine or phenytoin, and less asthenia and ataxia than phenytoin. Clinical experience would therefore suggest that lamotrigine is a particularly effective and generally well tolerated broad-spectrum agent for adjunctive treatment of both partial epilepsy and idiopathic generalised epilepsy in adults and children. Initial indications point to the drug filling an increasingly important future role in the monotherapy of newly diagnosed epilepsy.

Adult↗

PubMed1995

Artesunate. A review of its pharmacology and therapeutic efficacy in the treatment of malaria.

Artesunate is an antimalarial agent, available in oral, rectal and parenteral formulations, that provides a rapid clinical effect in patients with Plasmodium falciparum malaria. The rapidity of effect, availability of an intravenous and intramuscular formulation and convenient dosage regimen make artesunate an ideal candidate for the treatment of severe malaria, including cerebral disease. While some results have been promising, there is no clear evidence to date that artesunate reduces mortality in patients with cerebral malaria to any greater extent than standard quinine therapy. When given as monotherapy, treatment should be continued for at least 5 to 7 days to prevent recrudescence. Combination therapy with mefloquine allows artesunate to be administered over 3 days or less, with a satisfactory clinical outcome maintained. Although optimal dosages remain to be determined, this combination continues to provide the rapid onset of clinical effect observed with artesunate monotherapy, but decreases the rate of recrudescence to 2% (i.e. radical cure rate of 98%) when used as treatment in patients with uncomplicated malaria from areas with a high risk of multidrug-resistance falciparum malaria. Although assessment of tolerability is complicated by the difficulty of distinguishing between disease- and treatment-related events, artesunate and artesunate-mefloquine combinations appear to be well tolerated in adults and children. Indeed, it is possible that prior administration of artesunate may reduce the incidence of mefloquine-induced vomiting. Clinical findings to date have not revealed any pattern of resistance to artesunate after use of the drug. However, given the history of the development of resistance to other antimalarial drugs, the use of artesunate should be restricted to areas of multidrug resistance, the drug should be used in combination with a longer acting agent such as mefloquine, and it should be used in regimens that provide radical cure rates of 90 to 100%. If used according to these treatment principles, artesunate will provide a well tolerated and valuable addition to the current extremely limited treatment options for multidrug-resistant falciparum malaria, a widespread parasitic disease associated with considerable mortality.

Antimalarials↗

PubMed1994

Trazodone. A review of its pharmacology, therapeutic use in depression and therapeutic potential in other disorders.

Trazodone is a triazolopyridine derivative, chemically and pharmacologically unrelated to other currently available antidepressants. It possesses antidepressant, and also some anxiolytic and hypnotic activity. Results from a small number of short term (4 to 6 weeks) comparative studies in a total of 320 evaluable elderly patients with major depression, suggest that trazodone at therapeutic doses is superior to placebo and as effective as amitriptyline, imipramine, fluoxetine and mianserin in relieving depressive symptoms. Trazodone has also been successfully used in a small number of patients with depression and pre-existing cardiovascular disease. More recently, trazodone has been used as a hypnotic for psychotropic-induced or other insomnias with some success. However, further clinical experience is needed to confirm these preliminary results. In the elderly, maximum tolerated doses of trazodone are 300 to 400 mg/day, although higher doses of up to 600 mg/day are tolerated by younger patients. Drowsiness is commonly reported, but the incidences of both anticholinergic and cardiovascular effects were notably lower in elderly patients treated with trazodone compared with older tricyclic antidepressants. However, undesirable effects such as orthostatic hypotension, arrhythmias and priapism need to be closely monitored. In comparison with other currently available agents, particularly the tricyclic antidepressants, trazodone is relatively safe in overdose. In terms of therapeutic efficacy, trazodone appears to confer little advantage over other available antidepressants. While limited data suggest that trazodone may be better tolerated than older tricyclic antidepressants, especially in the elderly, there is a paucity of data at present comparing trazodone with the secondary amine tricyclic agents, serotonin reuptake inhibitors or moclobemide. Bearing this in mind, trazodone may be of use in elderly patients in whom anxiety and insomnia are problematic, and in those patients who are unresponsive to or cannot tolerate therapy with other agents. Studies are also required to define the place of trazodone in long term prophylactic therapy for recurrent depression. Future trials comparing both its efficacy and tolerability with those of newer agents will ascertain whether trazodone becomes a first line agent within these subsets of elderly patients.

Aged↗

PubMed1994

Pimobendan. A review of its pharmacology and therapeutic potential in congestive heart failure.

Pimobendan is a novel cardiotonic vasodilator (inodilator) which derives its inotropic activity from a combination of phosphodiesterase III inhibition and sensitisation of myocardial contractile proteins to calcium. The acute haemodynamic benefits of pimobendan (2.5 to 10mg orally; 5 to 10mg intravenously) seen in patients maintained on conventional diuretic, digitalis and vasodilator therapy for chronic heart failure (increases in cardiac output and stroke volume, and reductions in left ventricular preload and afterload) persisted on short term (1 month) therapy, and showed only limited evidence of attenuation on longer term (6 months) oral therapy with pimobendan 2.5 or 5mg twice daily. Adjunctive therapy with pimobendan 1.25 to 5mg twice daily for periods of 3 to 6 months improved exercise tolerance on symptom-limited exercise testing, New York Heart Association (NYHA) functional class, and quality of life, and additionally reduced the need for hospitalisation in patients with moderate to severe chronic heart failure. Pimobendan appears to be well tolerated at therapeutic doses (1.25 to 5mg twice daily) in patients with chronic heart failure, and preliminary indications suggest that it is largely devoid of the proarrhythmic effects of classical phosphodiesterase III inhibitors. Although information regarding the long term effects of pimobendan on mortality is currently lacking, the drug nevertheless shows potential benefit as an adjunctive therapy in patients with chronic heart failure.

Administration, Oral↗

PubMed1994

Etidronic acid. A review of its pharmacological properties and therapeutic efficacy in resorptive bone disease.

Etidronic acid is an orally and intravenously active bisphosphonate, which is believed to inhibit resorption of bone via a number of cellular mechanisms, including alteration of osteoclastic activity. In studies of patients with symptomatic Paget's disease, etidronic acid 5 to 20 mg/kg/day administered orally rapidly decreased the biochemical indices of bone turnover. Mineralisation defects in forming bone may be avoided by the use of an initial dosage of 5 mg/kg/day for up to 6 months; dosages above 10 mg/kg/day should be limited to 3 months' duration, and dosages greater than 20 mg/kg/day should be avoided. Although 3-day intravenous therapy with etidronic acid 7.5 mg/kg/day has shown superior efficacy to rehydration and forced diuresis in the management of hypercalcaemia of malignancy, the efficacy of the drug is lower than that of the newer bisphosphonates, pamidronic acid and clodronic acid. Clinical studies involving postmenopausal women with established osteoporosis have indicated that oral etidronic acid 400 mg/day for 14 days as part of a 90-day cycle, repeated for up to 3 years, increases the bone mineral density (BMD) of the lumbar vertebrae and appears to reduce the incidence of vertebral fracture. Published data suggest that etidronic acid shows similar efficacy to hormone replacement therapy (HRT) in these respects. The above dosage also appears to be effective in preventing corticosteroid-induced osteoporosis when administered as part of an intermittent, cyclical regimen. Etidronic acid in higher dosages (10 to 20 mg/kg/day orally) is effective in reducing the incidence of heterotopic ossification and its ensuing complications in both neurological and post-surgical patients. Etidronic acid is well tolerated by the majority of patients, with gastrointestinal complaints reported most commonly, but tends to delay the normal mineralisation of forming bone when administered continuously at higher dosages for prolonged periods. This is of little consequence where short term treatment is involved, but may be detrimental to those patients receiving longer courses of therapy. This effect may be minimised or avoided by using the lowest effective dosage for as short a time as possible (as in the above recommendations for Paget's disease), or by the use of intermittent cyclical therapy (as in the management of osteoporosis). Etidronic acid therefore retains a role in the management of resorptive bone disease, particularly in the treatment of Paget's disease, the prevention of heterotopic ossification, and as a second-line option in postmenopausal osteoporosis. However, the development of newer bisphosphonates requires that these compounds be continually compared and re-evaluated.

Bone Diseases↗

PubMed1994

Rifabutin. A review of its antimicrobial activity, pharmacokinetic properties and therapeutic efficacy.

Rifabutin is a derivative of rifamycin S with activity against mycobacteria including atypical organisms such as Mycobacterium avium and M. intracellulare, also referred to as Mycobacterium avium-intracellulare complex (MAC). To date, rifabutin is the only drug to have been studied in large prospective placebo-controlled trials that has been shown to significantly reduce the incidence of disseminated MAC infection when administered prophylactically as a single agent to patients with acquired immune deficiency syndrome (AIDS). Initial studies also indicate that rifabutin may be a useful component of multiple drug regimens for the treatment of MAC infection, although further studies combining rifabutin with other recently available antimycobacterial drugs are required to determine the most effective regimens. When rifabutin is combined with at least two other antimycobacterial drugs, the combination appears to be of similar efficacy to rifampicin (rifampin)-containing regimens in patients with newly diagnosed pulmonary tuberculosis. Since available therapy for MAC infection in patients with AIDS is still suboptimal, rifabutin, at present the only first-line agent for prophylaxis against disseminated MAC infection in patients with advanced human immunodeficiency virus (HIV) infection, has the potential to make a valuable contribution to the continuing attempts to preserve the quality of life of patients with AIDS.

AIDS-Related Opportunistic Infections↗

PubMed1994

Risperidone. A review of its pharmacology and therapeutic potential in the treatment of schizophrenia.

Risperidone, a benzisoxazol derivative, is a novel antipsychotic agent which combines potent serotonin (5-hydroxytryptamine) 5-HT2 and dopamine D2 receptor antagonism. Development of the drug was stimulated by reports that the selective serotonin 5-HT2 antagonist ritanserin improved the negative symptoms of schizophrenia and decreased extrapyramidal symptoms when combined with haloperidol. The relatively low incidence of extrapyramidal symptoms with risperidone may reflect a preferential action on mesolimbic rather than nigrostriatal dopaminergic pathways. Recent clinical investigation suggests that risperidone is of at least comparable efficacy to haloperidol and perphenazine in improving the symptoms of acute and chronic schizophrenia on short term administration. Advantages offered by risperidone over haloperidol include a faster onset of antipsychotic action, a lower incidence of extrapyramidal effects and possibly greater efficacy against the negative symptoms of schizophrenia. If these benefits prove to be maintained during long term therapy, risperidone is likely to make a significant contribution to the treatment of schizophrenia.

Absorption↗

PubMed1994

Loratadine. A reappraisal of its pharmacological properties and therapeutic use in allergic disorders.

Loratadine is a long-acting antihistamine agent, exhibiting partial selectivity for peripheral histamine H1-receptors. To date, loratadine has been evaluated in allergic rhinitis, urticaria and, to a limited extent, in asthma. In several large controlled comparative clinical studies, loratadine was superior to placebo, faster acting than astemizole and as effective as azatadine, cetirizine, chlorpheniramine (chlorphenamine), clemastine, hydroxyzine, mequitazine and terfenadine in patients with allergic rhinitis and chronic urticaria. The clinical effectiveness of loratadine in asthma is at present unclear. Loratadine is well tolerated. At dosages of 10 mg daily, commonly reported adverse events were somnolence, fatigue and headache. Sedation occurred less frequently with loratadine than with azatadine, cetirizine, chlorpheniramine, clemastine and mequitazine. Serious ventricular arrhythmias, as reported with some other second generation histamine H1-receptor antagonists, have not been observed with loratadine to date. Thus, loratadine, with its attributes of once daily administration, fast onset of action and essentially nonsedating properties, would appear to be an appropriate first-line agent for the treatment of allergic rhinitis or urticaria.

Animals↗

PubMed1993

Propafenone. A reappraisal of its pharmacology, pharmacokinetics and therapeutic use in cardiac arrhythmias.

Propafenone is an orally active sodium channel blocking agent with beta-adrenoceptor antagonist and weak calcium antagonist activity. The pharmacokinetic profile of propafenone is complex, characterised as typically nonlinear, saturable, stereoselective and dependent on both dose and debrisoquin metaboliser phenotype; individualised dosage titration is required. Both placebo- and drug-controlled studies have confirmed the efficacy of propafenone in the treatment of premature ventricular complexes, ventricular couplets and nonsustained ventricular tachycardia; in a large meta-analysis, propafenone together with amiodarone, flecainide and encainide were significantly more effective in the control of ventricular ectopy than other antiarrhythmic agents. However, the use of propafenone in these indications, like that of other antiarrhythmic agents, is likely to be limited to patients with a favourable risk-to-benefit ratio. Propafenone has also demonstrated efficacy in the treatment of malignant ventricular arrhythmias (ventricular fibrillation and sustained ventricular tachycardia); preliminary mortality data obtained with propafenone have been encouraging in this patient group. In addition, propafenone has a favourable noncardiac tolerability profile and beta-adrenoceptor antagonist activity, which may offer advantages in some specific patient groups. The area of research concerning propafenone which has shown the greatest expansion over the past 5 years is in the treatment of supraventricular arrhythmias. Propafenone has marked efficacy in patients with Wolff-Parkinson-White syndrome and has been recommended as a first-line prophylactic agent in those with rapid anterograde conduction. Propafenone is also effective in the conversion of atrial fibrillation to sinus rhythm, although comparative studies are required to determine advantages over more established agents. Propafenone use has been successfully extended to children with limited data demonstrating consistent efficacy in the control of junctional ectopic tachycardia. As with all antiarrhythmic agents, propafenone has the potential to induce arrhythmias. Comparative studies are required to assess in more detail the cardiac tolerability profile of propafenone against other class Ic agents. In conclusion, propafenone offers a broad spectrum of activity in the treatment of cardiac arrhythmias, although its use in patients with potentially malignant arrhythmias will remain limited for the present. Due to its unique pharmacodynamic profile, propafenone deserves consideration as an individual agent.

Animals↗

PubMed1993

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

Alfuzosin, a new quinazoline derivative, acts as a selective and competitive antagonist of alpha 1-adrenoceptor-mediated contraction of prostatic, prostatic capsule, bladder base and proximal urethral smooth muscle, thereby reducing the tone of these structures. Consequently, urethral pressure and resistance, bladder outlet resistance, bladder instability and symptoms associated with benign prostatic hyperplasia are reduced. A limited range of clinical studies have shown oral alfuzosin to be more effective than placebo (in studies of < or = 6 months duration), to have sustained effects on long term administration (< or = 30 months), and to be comparable with the alpha 1-adrenoceptor antagonist prazosin, in the symptomatic treatment of benign prostatic hyperplasia. This is reflected in increases in urinary flow rate and decreases in symptom score and residual urinary volume. The most marked improvements occur in patients with severe pretreatment urinary flow abnormalities. Furthermore, preliminary results suggest a beneficial effect of alfuzosin on quality of life in patients with benign prostatic hyperplasia. The overall incidence of adverse effects appears similar to that with placebo, and the incidence of vasodilatory-related adverse effects appears lower than that with prazosin. The relative selectivity of alfuzosin for alpha 1-adrenoceptors in the genitourinary tract compared with receptors in the vasculature is a potential advantage over other alpha-adrenoceptor antagonists, including prazosin, as the symptoms of benign prostatic hyperplasia may be reduced by alfuzosin at doses that have minimal vasodilatory effects, thereby minimising postural hypotension and syncope. However, vasodilatory-related adverse effects are the most common adverse effects that occur with alfuzosin, and dose and first-dose hypotensive relationships, especially in the elderly, cannot be excluded at this stage in the clinical use of alfuzosin. The full potential of alfuzosin in the symptomatic treatment of benign prostatic hyperplasia will be clarified by further long term comparative studies (with large patient numbers) against placebo and other alpha 1-adrenoceptor antagonists. Nevertheless, oral alfuzosin 7.5 to 10 mg/day in divided doses appears to be a promising first-line agent for symptomatic treatment of noncomplicated mild to moderate benign prostatic hyperplasia in patients with a high dynamic component to their obstruction. In addition, alfuzosin offers an alternative to prostatectomy (the current 'gold standard') in patients who require surgery but are unfit for this treatment, and in patients requiring symptomatic relief while awaiting surgery.

Adrenergic alpha-Antagonists↗

PubMed1993

Flupirtine. A review of its pharmacological properties, and therapeutic efficacy in pain states.

Flupirtine is a novel non-opiate centrally acting analgesic agent with muscle relaxant properties, advocated for use in a number of pain states. Preliminary evidence suggests that flupirtine 100 to 200mg orally or 150mg rectally 3 to 4 times daily (maximum daily dose 600mg) is more effective than placebo in relieving moderate acute pain of various types. For the relief of pain due to surgery, traumatic injury, dental procedures, headache/migraine and abdominal spasms, flupirtine has proved at least as effective as the opiate analgesics codeine, dihydrocodeine and pentazocine, the nonsteroidal anti-inflammatory agents suprofen, diclofenac and ketoprofen, as well as dipyrone and paracetamol (acetaminophen). Although evidence to support a role in the treatment of chronic pain is limited, flupirtine has been found as effective as pentazocine in short term trials of patients with muscular or neuralgiform pain, dysmenorrhoea, soft tissue rheumatism or cancer pain. The safety profile of flupirtine has not yet been fully established, although initial evidence suggests that adverse reactions, while frequent, are usually minor in nature. The most common reactions are drowsiness, dizziness, dry mouth and various gastrointestinal complaints. In comparison with opiate drugs, flupirtine appears to produce fewer central nervous system effects, no respiratory or cardiovascular depression, and no overt tolerance or physical dependence on prolonged administration. If these initially favourable results are confirmed in larger long term trials, then flupirtine would appear to represent an effective analgesic for the relief of moderate pain, particularly that of musculoskeletal origin.

Aminopyridines↗

PubMed1993

Sotalol. An updated review of its pharmacological properties and therapeutic use in cardiac arrhythmias.

Sotalol is a nonselective beta-adrenoceptor antagonist which prolongs cardiac repolarisation independently of its antiadrenergic action (class III antiarrhythmic properties). The antiarrhythmic action of sotalol appears to arise predominantly from its class III properties, and the drug exhibits a broader antiarrhythmic profile than the conventional beta-blockers. Sotalol is effective in controlling paroxysmal supraventricular tachycardias and the ventricular response to atrial fibrillation/flutter in Wolff-Parkinson-White syndrome, in maintaining sinus rhythm after cardioversion of atrial fibrillation/flutter, and in preventing initiation of supraventricular tachyarrhythmias following coronary artery bypass surgery. Sotalol shows promise in the control of nonmalignant and life-threatening ventricular arrhythmias, particularly those associated with ischaemic heart disease. It is effective in suppressing complex forms of ventricular ectopy, displaying superior antiectopic activity to propranolol and metoprolol. The acute efficacy of sotalol in preventing reinduction of sustained ventricular tachyarrhythmias and suppressing spontaneous episodes of these arrhythmias on Holter monitoring is translated into long term prophylactic efficacy against arrhythmia recurrence in approximately 55 to 85% of patients with refractory life-threatening ventricular arrhythmias. In addition, sotalol offers the advantage over the class I agents of reducing cardiac and all-cause mortality in the high risk population with life-threatening ventricular arrhythmias. The adverse effects of sotalol are primarily related to its beta-blocking activity and its class III property of prolonging cardiac repolarisation. Sotalol is devoid of overt cardiodepressant activity in patients with mild or moderate left ventricular dysfunction. The overall arrhythmogenic potential is moderately low, but torsade de pointes may develop in conjunction with excessive prolongation of the QT interval due to bradycardia, hypokalaemia or high plasma concentrations of the drug. In summary, sotalol displays a broad spectrum of antiarrhythmic activity, is haemodynamically well tolerated, and confers a relatively low proarrhythmic risk. It is likely to prove particularly appropriate in the treatment and prophylaxis of life-threatening ventricular tachyarrhythmias.

Arrhythmias, Cardiac↗