Biomedical subjects

H M Bryson

Publications and source records attributed to H M Bryson.

At least 37 records · Page 2Linked to original sources

PubMed1995

Ceftazidime. An update of its antibacterial activity, pharmacokinetic properties and therapeutic efficacy.

Ceftazidime is a third generation cephalosporin antibacterial agent which, since its introduction in the early 1980s, has retained a broad spectrum of in vitro antimicrobial activity and clinical utility in serious infections. However, increasing resistance to ceftazidime and other third generation cephalosporins, particularly among Enterobacteriaceae, due to the emergence of plasmid-mediated extended spectrum beta-lactamases and the class I chromosomally mediated beta-lactamases, is of concern. There is now a wealth of information on the pharmacokinetics of the drug. enabling ceftazidime to be used predictably, and with a low potential for adverse effects, in a diversity of patient populations. Overall, ceftazidime remains an effective agent for the treatment of serious infection, particularly those due to major nosocomial pathogens, and respiratory infections in patients with cystic fibrosis. Ceftazidime-containing regimens also remain an important option for the empirical therapy of febrile episodes in neutropenic patients. The tolerability profile of ceftazidime makes the drug a useful option in seriously ill patients who are at risk of developing adverse events with other antibacterial agents. Although patterns of bacterial resistance have changed in the ensuing years since its introduction, judicious use of this important agent will help maintain its present clinical utility.

Adult↗

PubMed1995

Meropenem. A review of its antibacterial activity, pharmacokinetic properties and clinical efficacy.

The parenteral carbapenem meropenem is relatively stable to inactivation by human renal dehydropeptidase (DHP-1) and does not require concomitant administration of a DHP-1 inhibitor such as cilastatin. It has a broad spectrum of antibacterial activity in vitro, the majority of Gram-negative, Gram-positive and anaerobic pathogens being highly susceptible to the drug. Meropenem has shown clinical and bacteriological efficacy in the treatment of a wide range of serious infections in adults and children which is at least comparable with that of currently available treatment options. Its clinical and bacteriological efficacy is similar to that of imipenem/cilastatin, clindamycin plus tobramycin and cefotaxime plus metronidazole in the treatment of intraabdominal infections; cefotaxime or ceftriaxone in the treatment of meningitis; imipenem/cilastatin, and ceftazidime with or without an aminoglycoside, in lower respiratory tract infections; and imipenem/cilastatin or ceftazidime in the treatment of urinary tract infections. Satisfactory clinical and bacteriological response rates have also been achieved in patients with skin and skin structure infections, obstetric and gynaecological infections or septicaemia, and in immunocompromised patients with febrile episodes. Preliminary findings also indicate efficacy in the treatment of respiratory tract infections in patients with cystic fibrosis. The tolerability profile of meropenem is generally similar to that of comparator agents, although it is associated with a lower incidence of adverse gastrointestinal effects (nausea and vomiting) than imipenem/cilastatin. Importantly, the incidence of seizures in patients with meningitis is not increased following administration of meropenem. Thus, meropenem is an effective broad spectrum antibacterial drug for the treatment of a wide range of infections including polymicrobial infections in both adults and children, with comparable efficacy to imipenem/cilastatin and various other treatment regimens. Meropenem is likely to be of greatest value as empiric monotherapy in the treatment of serious infections for those caused by multiply-resistant pathogens. Further clinical experience is necessary, however, to ultimately define its place in therapy.

Absorption↗

PubMed1995

Deflazacort. A review of its pharmacological properties and therapeutic efficacy.

Deflazacort is an oxazoline derivative of prednisolone with anti-inflammatory and immunosuppressive activity. Both short (4 to 6 weeks) and longer term (13 to 52 weeks) studies have shown deflazacort to be as effective as prednisone or methylprednisolone in patients with rheumatoid arthritis. The drug was at least as effective as prednisone in children with juvenile chronic arthritis. Insufficient data are available to draw firm conclusions regarding the efficacy of deflazacort as treatment for patients with severe asthma, but the drug has demonstrated some efficacy as treatment for nephrotic syndrome and other applications such as Duchenne dystrophy, systemic lupus erythematosus, uveitis and transplantation. The overall incidence of adverse events in deflazacort recipients (16.5%) is lower than that recorded in patients treated with prednisone (20.5%) or methylprednisolone (32.7%) and similar to that in betamethasone recipients (15.3%). Gastrointestinal symptoms are the most frequently reported adverse events in deflazacort recipients; other adverse events associated with the drug include metabolic and nutritional disorders, central and peripheral nervous system disturbances and psychiatric disorders. In general, deflazacort appears to have less effect than prednisone on parameters which may be associated with the development of corticosteroid-induced osteoporosis. Further, the drug appears have less negative impact on growth rate in children with diseases requiring corticosteroid therapy. In a study of 2 months' duration in patients with conditions requiring corticosteroid treatment, moderate dosages of deflazacort produced no clinically relevant diabetogenic effects. Thus, deflazacort may be associated with less serious metabolic sequelae than prednisone but further well designed long term trials are required to confirm this. In the meantime, in adults, deflazacort should be reserved for use in those pre-disposed to, or who develop, intolerable metabolic sequelae during treatment with corticosteroids. In children, however, even though available efficacy data are minimal, deflazacort should be considered as an initial option in those requiring corticosteroid therapy since the adverse effects caused by this drug class are particularly debilitating in this patient group.

Anti-Inflammatory Agents↗

PubMed1995

Propofol. An update of its use in anaesthesia and conscious sedation.

Propofol is an intravenous sedative hypnotic agent which rapidly and reliably causes loss of consciousness. It is also associated with a quick and 'smooth' recovery, which distinguishes it from many of the more traditional anaesthetic regimens. Like other intravenous agents, propofol is both a cardiovascular and a respiratory depressant; however, the risk of these effects can be lessened by appropriate dosage adjustment or patient management. Anaphylaxis with propofol is rare. Propofol anaesthesia in day case surgery is consistently associated with a quicker early recovery than other intravenous agents and the more traditional anaesthetic regimens. Savings in time to discharge were more variable compared with these regimens, although propofol was commonly associated with less post-operative nausea and vomiting in this period. In the future, the relative benefits of propofol compared with the newer volatile agents (desflurane and sevoflurane) and propofol/volatile agent combinations need to be examined in this clinical setting. There is now clinical experience with propofol in major surgical procedures including cardiac and neurosurgery. Propofol has also been investigated as a sedative accompanying regional or local anaesthesia for diagnostic and therapeutic procedures, and in other clinical settings (ophthalmic surgery, cardioversion and electroconvulsive therapy). The unique antiemetic, antiepileptic and antipruritic effects of propofol may further broaden its appeal. As a result of its favourable recovery profile, propofol holds a central place in day case surgery anaesthesia. Accumulating clinical experience in cardiac and neurosurgery suggests that the full potential of propofol has yet to be realised.

Anesthetics↗

PubMed1995

Teicoplanin. A pharmacoeconomic evaluation of its use in the treatment of gram-positive infections.

Teicoplanin, a glycopeptide antibiotic, is active against Gram-positive organisms, including methicillin-resistant staphylococci. It has demonstrated similar efficacy to vancomycin in the treatment of Gram-positive infections in febrile patients with neutropenia; fewer comparative data are available in patients with other infection types. Compared with vancomycin, teicoplanin is associated with less nephrotoxicity, appears to cause fewer anaphylactoid reactions, requires less monitoring and is more convenient to administer (once daily by intravenous bolus or intramuscular injection vs 2 to 4 times daily by intravenous infusion). Two European cost-minimisation studies have demonstrated that while the acquisition cost per dose of teicoplanin was approximately twice that of vancomycin, the cost of 2 weeks' therapy with either agent was similar (difference of 1 to 2%). However, in order to fully explore potential differences between these agents, a full economic analysis which considers all treatment-related costs is needed. Home therapy of Gram-positive infections, a setting in which teicoplanin may be preferred over vancomycin because of its tolerability profile and ease of administration, is particularly worthy of future economic study. Thus, there are a number of areas needing further study before the optimum formulary positioning of teicoplanin can be definitely stated. Nevertheless, present evidence suggests that teicoplanin is likely to have pharmacoeconomic advantages over vancomycin in at least some situations.

Cost-Benefit Analysis↗

PubMed1994

Cefepime. A review of its antibacterial activity, pharmacokinetic properties and therapeutic use.

Cefepime is a 'fourth' generation cephalosporin that has a broader spectrum of antibacterial activity than the third generation cephalosporins and is more active in vitro against Gram-positive aerobic bacteria. The fact that cefepime is stable to hydrolysis by many of the common plasmid- and chromosomally-mediated beta-lactamases, and that it is a poor inducer of type I beta-lactamases, indicates that cefepime may be useful for treatment of infections resistant to earlier cephalosporins. In comparative trials, cefepime 1 to 2 g, usually administered intravenously twice daily, was as effective as ceftazidime 1 to 2 g, usually administered 3 times daily, for treatment of bacteraemia and infections of the lower respiratory tract, urinary tract, pelvis and skin and skin structures. Furthermore, cefepime was as effective as ceftazidime and piperacillin or mezlocillin in combination with gentamicin when administered as empirical treatment for fever in patients with neutropenia. A limited number of trials have found cefepime to be as effective as cefotaxime for the treatment of gynaecological and lower respiratory tract infections. Similarly, cefepime 2 g twice daily intravenously (alone or in combination with metronidazole) was as effective as gentamicin in combination with mezlocillin or clindamycin, respectively, for the treatment of intra-abdominal infection. Cefepime has a linear pharmacokinetic profile, an elimination half-life of approximately 2 hours and is primarily excreted by renal mechanisms as unchanged drug. Cefepime has a tolerability profile similar to that of other parenteral cephalosporins; adverse events are primarily gastrointestinal in nature. A total of 1.4 and 2.9% of patients receiving cefepime < or = 2 g/day and > 2 g/day, respectively, required treatment withdrawal as a result of any adverse event. Thus, cefepime has the advantage of an improved spectrum of antibacterial activity, and is less susceptible to hydrolysis by some beta-lactamases, compared with third generation cephalosporins. Despite these advantages, cefepime has not been found to be more effective than ceftazidime and cefotaxime in clinical trials, although most trials selected patients with organisms sensitive in vitro to both comparator agents. Further trials, particularly in areas of widespread bacterial resistance, are required to confirm the positioning of cefepime for treatment of serious infection, and in particular to further explore whether its potential advantages result in clinical benefits.

Aging↗

PubMed1994

Piperacillin/tazobactam. A review of its antibacterial activity, pharmacokinetic properties and therapeutic potential.

Combining tazobactam, a beta-lactamase inhibitor, with the ureidopenicillin, piperacillin, successfully restores the activity of piperacillin against beta-lactamase-producing bacteria. Tazobactam has inhibitory activity, and therefore protects piperacillin against Richmond and Sykes types II, III, IV and V beta-lactamases, staphylococcal penicillinase and extended-spectrum beta-lactamases. However, tazobactam has only species-specific activity against class I chromosomally-mediated enzymes. Resistant organisms include some Citrobacter spp., Enterobacter spp., Serratia spp., Xanthomonas maltophilia and Enterococcus faecium. Consistent with its in vitro activity, preliminary clinical data indicate that the fixed combination of piperacillin/tazobactam (dose ratio 8:1) is effective in the treatment of moderate to severe polymicrobial infections, including intra-abdominal, skin and soft-tissue and lower respiratory tract infections. In limited comparative trials, piperacillin/tazobactam demonstrated equivalent or better efficacy than standard comparator regimens in these infections. Piperacillin/tazobactam in combination with an aminoglycoside was effective in the empirical treatment of fever in patients with neutropenia and compared favourably with ceftazidime in combination with an aminoglycoside, although second-line therapy with a glycopeptide antibiotic may be indicated in unresponsive episodes. Data from phase III trials indicate that piperacillin/tazobactam has a tolerability profile typical of a penicillin agent. Piperacillin/tazobactam provides a broad spectrum of antibacterial activity in a convenient single formulation suitable for use in the treatment of polymicrobial infections. Possible limitations concern its restricted activity against class I beta-lactamases, enzymes that are becoming increasingly important in the nosocomial environment. Combined therapy with an aminoglycoside may be necessary in more serious infections.

Animals↗

PubMed1994

Levofloxacin. A review of its antibacterial activity, pharmacokinetics and therapeutic efficacy.

Levofloxacin, an oral fluoroquinolone antibacterial agent, is the optical S-(-) isomer of ofloxacin. In vitro it is generally twice as potent as ofloxacin. Levofloxacin is active against most aerobic Gram-positive and Gram-negative organisms and demonstrates moderate activity against anaerobes. Drug penetration into body tissues and fluids is rapid and widespread after oral administration. In clinical trials conducted in Japan, oral levofloxacin has demonstrated antibacterial efficacy against a variety of infections, including upper and lower respiratory tract, genitourinary, obstetric, gynaecological and skin and soft tissues. In comparative trials with ofloxacin, levofloxacin, at half the daily dosage of ofloxacin, showed equivalent efficacy and a reduced incidence of adverse effects in the treatment of lower respiratory tract and complicated urinary tract infections. Levofloxacin has a tolerability profile similar to that of other oral fluoroquinolones, with gastrointestinal and central nervous system effects reported most commonly. Theophylline dosage adjustment does not appear to be necessary in patients receiving concomitant levofloxacin. Coadministration with antacids or with other drugs containing divalent or trivalent cations reduces levofloxacin absorption. Thus, levofloxacin has potential as a broad spectrum antibacterial drug in the treatment of a variety of infections. However, clinical trials recruiting non-Japanese patients are in progress and these results will form a basis on which future recommendations for the broader use of levofloxacin can be made.

Administration, Oral↗

PubMed1994

Foscarnet. A reappraisal of its antiviral activity, pharmacokinetic properties and therapeutic use in immunocompromised patients with viral infections.

The DNA polymerase of human herpes viruses, including cytomegalovirus (CMV), and the reverse transcriptase of human immunodeficiency virus (HIV) are selectively inhibited in vitro by the pyrophosphate analogue foscarnet. Inhibition is reversible on withdrawal of foscarnet and additive or synergistic effects have been demonstrated in vitro with other antiviral drugs, including ganciclovir and zidovudine. Foscarnet appears to have negligible effects on host enzymes and cells. Complete or partial clinical resolution of ocular symptoms is obtained in more than 89% of patients with acquired immunodeficiency syndrome (AIDS) and CMV retinitis during foscarnet induction therapy, but relapse occurs soon after ceasing treatment. Maintenance treatment given daily can extend the period of remission considerably. Foscarnet and ganciclovir monotherapy had similar efficacy in the treatment of CMV retinitis in patients with AIDS in several studies, and have been used concomitantly in immunocompromised patients with recalcitrant CMV infections. In 1 trial, patients receiving foscarnet survived for significantly longer than those receiving ganciclovir. Foscarnet has been used successfully in the treatment of limited numbers of immunocompromised patients with CMV-associated gastrointestinal (improvement in over 67% of patients) and other infections. Aciclovir-resistant herpes simplex infections in immunocompromised patients have also been treated successfully with foscarnet. Almost 90% of a foscarnet dose is excreted in the urine. Reversible nephrotoxicity is common during foscarnet therapy, but may be reduced by dosage adjustment and adequate hydration. Anaemia, nausea and vomiting, disturbances in electrolyte levels and genital ulceration have also been associated with administration of the drug. The different tolerability profiles of foscarnet and zidovudine facilitate the use of these agents in combination in patients with AIDS and CMV infection; whereas ganciclovir, like zidovudine, is associated with dose-limiting haematological toxicity. The apparent survival benefits seen in these patients when receiving foscarnet and zidovudine (possibly linked to synergy between zidovudine and foscarnet and/or the inherent anti-HIV activity of foscarnet), appear to offer potentially important advantages for foscarnet over ganciclovir in the treatment of selected patients with AIDS and CMV infections.

AIDS-Related Opportunistic Infections↗

PubMed1994

Lacidipine. A review of its pharmacodynamic and pharmacokinetic properties and therapeutic potential in the treatment of hypertension.

Lacidipine is an orally administered calcium channel blocker of the dihydropyridine class, which shows selectivity for vascular smooth muscle over cardiac tissue and has a long duration of action. In studies using ambulatory blood pressure monitoring, lacidipine 2 to 8mg administered once daily in the morning reduced blood pressure over 24 hours, with the reductions being greater during the day than at night in some studies. 77 to 87% of patients with mild to moderate hypertension had their blood pressure controlled by treatment with lacidipine 2 to 8 mg/day for 1 to 4 months in dose-finding studies. When administered once daily, lacidipine 4 to 6 mg was equivalent in antihypertensive efficacy to hydrochlorothiazide 25 to 50 mg/day, atenolol 50 to 100 mg/day, and the prototype calcium channel blocker nifedipine 20 to 40 mg twice daily (sustained-release formulation). The adverse effects of lacidipine are those common to other dihydropyridine calcium channel blockers, and include headache, flushing, ankle oedema, dizziness and palpitations. The long term effects of lacidipine on cardiovascular morbidity and mortality, and possible additional clinical benefits in terms of its antiatherosclerotic effects, are under investigation; the outcome of these studies will be important in defining the future role of this agent in the treatment of hypertension. Thus, available evidence suggests lacidipine provides a further alternative to the dihydropyridine calcium channel blockers currently available for the treatment of essential hypertension.

Adult↗

PubMed1994

Porcine-derived lung surfactant. A review of the therapeutic efficacy and clinical tolerability of a natural surfactant preparation (Curosurf) in neonatal respiratory distress syndrome.

Porcine-derived lung surfactant (PLS; Curosurf) has shown efficacy in neonatal respiratory distress syndrome. PLS consists of phospholipids, mainly dipalmitoylphosphatidylcholine, the primary surface-active agent of natural lung surfactant, and pulmonary surfactant-associated proteins which facilitate spreading and adsorption of the surface-active agent at the air-alveolar interface. Intratracheal administration of a single dose of PLS 200 mg/kg significantly improves the survival rate and reduces the incidence of bronchopulmonary dysplasia at 28 days in premature infants (birthweight 700 to 2000g) with severe respiratory distress syndrome (fraction of inspired oxygen > or = 0.60). PLS also reduces the incidence of air leak events such as pulmonary interstitial emphysema and pneumothorax. The response rate may be further improved by administration of additional 100 mg/kg doses at 12-hour intervals to infants showing a poor response or relapse after a single dose. PLS prophylaxis reduces the incidence and severity of respiratory distress syndrome in premature infants at high risk of developing the disease; however, it remains unclear whether the eventual clinical outcome is similar or superior to that observed in infants who receive rescue treatment. PLS is well tolerated and does not appear to increase the incidence of complications of prematurity or respiratory distress syndrome, including patent ductus arteriosus and intraventricular haemorrhage. Although its effect on long term development require further investigation, early indications are that PLS is not associated with any long term adverse sequelae. Comparative trials are clearly warranted to determine the efficacy and tolerability of PLS relative to that of other available surfactant preparations, particularly to explore preliminary indications that a more rapid effect of natural surfactants such as PLS (compared with synthetic products) may correlate with improved clinical outcomes, and that PLS may result in fewer complications than synthetic preparations. Thus, available data show PLS to be a very effective agent for the treatment and prophylaxis of neonatal respiratory distress syndrome, and that it may have some advantages over synthetic preparations.

Animals↗

PubMed1994

Dornase alfa. A review of its pharmacological properties and therapeutic potential in cystic fibrosis.

By cleaving neutrophil-derived DNA present in the infected lungs of patients with cystic fibrosis (CF), dornase alfa (recombinant human deoxyribonuclease I) reduces the adhesiveness and viscoelasticity of CF sputum. Well designed clinical studies performed in patients with CF and mild to moderate pulmonary disease [forced vital capacity (FVC) > or = 40% of predicted value] show that aerosolised dornase alfa improves lung function, achieving a 6 to 7% increase from baseline in forced expiratory volume in 1 second (FEV1) after 6 months' therapy. Improvements in general well-being and CF-related symptoms were also noted by patients. Importantly, dornase alfa reduced the relative risk of respiratory exacerbations requiring parenteral antibiotics by 22 to 34% compared with placebo. Short term studies with dornase alfa in patients with more severe pulmonary disease (FVC < 40% of predicted value) and in those with acute infectious exacerbations did not reveal any significant improvements in pulmonary function, although long term studies are required to fully determine efficacy. Voice alteration, laryngitis or rash may develop with dornase alfa therapy, although more clinical experience with the agent is required to define its tolerability profile. Anaphylaxis has not been reported with dornase alfa to date. In summary, aerosolised dornase alfa offers modest improvements in lung function and, importantly, a reduced risk of respiratory exacerbations in patients with CF and an FVC > or = 40% of the predicted value, thus representing an important adjunct agent in this patient group.

Aerosols↗

PubMed1994

Recombinant granulocyte-macrophage colony-stimulating factor (rGM-CSF): an appraisal of its pharmacoeconomic status in neutropenia associated with chemotherapy and autologous bone marrow transplant.

Recombinant granulocyte-macrophage colony-stimulating factor (rGM-CSF) expedites neutrophil recovery in cancer patients receiving chemotherapy with or without autologous bone marrow transplant (ABMT). The limited cost analyses available in patients undergoing ABMT support a cost reduction of about 25 to 35% with rGM-CSF therapy, relative to placebo, generated primarily by decreases of 20 to 30% in hospitalisation costs reflecting reductions in length of hospitalisation. Results of 1 trial show equivalent cost savings of 40% versus placebo with either rGM-CSF or recombinant granulocyte colony-stimulating factor (rG-CSF) in patients with chemotherapy-induced febrile neutropenia. Whether reduced infection rates seen with rGM-CSF may lessen costs of antimicrobial therapy is undetermined; however, a 16% decrease in this cost factor was reported in 1 evaluation of high dose chemotherapy with ABMT. No analyses have assessed the cost effectiveness of rGM-CSF as prophylaxis in patients receiving chemotherapy. Survival rates have increased in patients treated with rGM-CSF after bone marrow graft failure. In contrast, with the exception of one small trial, improvements in mortality or relapse rates have not occurred with rGM-CSF used prophylactically with chemotherapy, despite favourable effects on neutrophil recovery and facilitation of dose-intensified chemotherapy regimens. Similarly, survival has not increased in patients undergoing ABMT. The long term economic impact of rGM-CSF in these indications is thus unknown. Other factors predicted to produce modest cost savings include possible reductions in expenditure related to treating mucositis, and lowered transfusion requirements in some patients. Whether rGM-CSF may provide benefits in other areas that can be expressed in economic terms, such as quality of life, also remains to be established. On the whole, rGM-CSF has a good tolerability profile, obviating the need for costly monitoring procedures. Like other expensive biotechnology products, its cost effectiveness will be aided by implementation of appropriate prescribing techniques and protocols to minimise wastage. Thus, at present rGM-CSF therapy appears to offer a means of reducing hospitalisation costs, and therefore a substantial component of treatment expenditure, in patients undergoing ABMT or with chemotherapy-induced febrile neutropenia.

Anti-Bacterial Agents↗

PubMed1994

Enalapril: a review of quality-of-life and pharmacoeconomic aspects of its use in heart failure and mild to moderate hypertension.

Enalapril is an angiotensin converting enzyme (ACE) inhibitor with an established clinical profile. In patients with symptomatic heart failure, enalapril reduces overall mortality, death from progressive heart failure and hospitalisation rates. In those with asymptomatic left ventricular dysfunction, enalapril decreases the combined risk of death and development of heart failure, and the risk of death and hospitalisation. The effects of enalapril in reducing hospitalisation rates in symptomatic patients translate into net savings in healthcare costs in heart failure. Enalapril also produces modest benefits in quality-of-life (QOL) parameters in patients with symptomatic heart failure as shown in well controlled studies. Its effects appear similar to those of hydralazine plus isosorbide dinitrate. The influence of enalapril on quality of life in patients with asymptomatic disease is minimal but not deleterious. Enalapril generally either maintains or slightly improves quality of life from baseline in patients with mild to moderate hypertension. The drug appears to have a QOL profile that is more favourable than that of propranolol and similar to those of most other comparator drugs, as assessed by subjective measures of quality of life. Clarification is required of its QOL profile relative to that of captopril, in view of conflicting results in the literature. The effects of enalapril on cognitive and psychomotor function appear to resemble those of comparator agents. Thus, enalapril has modest beneficial effects on the quality of life of patients with symptomatic heart failure, while generally maintaining quality of life in patients with asymptomatic left ventricular dysfunction or mild to moderate hypertension. Enalapril is a cost-effective treatment in heart failure that would be expected to yield considerable cost savings in this therapeutic area.

Cost-Benefit Analysis↗

PubMed1994

Ceftriaxone. A pharmacoeconomic evaluation of its use in the treatment of serious infections.

Ceftriaxone possesses a broad spectrum of antimicrobial activity that includes the Gram-positive and Gram-negative aerobes commonly associated with serious infections. Its therapeutic efficacy is comparable to that of other third-generation cephalosporins and aminoglycoside-combination regimens. The most commonly reported adverse events with ceftriaxone are similar in incidence and severity to those reported with other third-generation cephalosporins. Notably, the drug has a favourable pharmacokinetic profile which allows once-daily administration. In comparative studies with other parenteral regimens requiring 3 to 6 daily doses, treatment with once-daily ceftriaxone reduced total antimicrobial drug costs (i.e. acquisition, preparation and administration costs) by 17 to 52%. Ceftriaxone was also more cost effective than ceftazidime and a variety of other antimicrobial treatment regimens (penicillins, cephalosporins, combination regimens) in the treatment of patients with community-acquired pneumonia or bronchopneumonia. This reflected lower drug and hospitalisation costs associated with a reduced length of hospital stay in ceftriaxone recipients. In noncomparative studies, ceftriaxone achieved considerable hospitalisation cost savings in patients with serious infections (mostly bone, joint, skin/skin structure infections), who were able to receive all or part of their antimicrobial therapy as outpatients. In one analysis which evaluated all direct and indirect costs (such as training programmes, transportation, time for visits and supplies) and benefits (such as hospitalisation cost savings, return to work or school, increased productivity) of outpatient ceftriaxone therapy, the overall benefit-cost ratio was approximately 5:1. The studies to date confirm that ceftriaxone is effective, well tolerated, convenient to administer and, when utilised appropriately, offers the potential for cost avoidance in patients with serious infections. Although additional well designed pharmacoeconomic analyses are needed to further evaluate its cost effectiveness, ceftriaxone should be considered an essential third-generation cephalosporin formulatory representative in most clinical settings.

Anti-Bacterial Agents↗

PubMed1994

Colfosceril palmitate. A pharmacoeconomic evaluation of a synthetic surfactant preparation (Exosurf Neonatal) in infants with respiratory distress syndrome.

Comprehensive clinical data provide strong evidence of the efficacy of the synthetic lung surfactant colfosceril palmitate (Exosurf Neonatal) administered as prophylaxis or rescue therapy in infants with respiratory distress syndrome (RDS). The use of rescue therapy with colfosceril palmitate is further supported by cost-effectiveness analyses which report a 9 to 48% reduction in the cost per survivor compared with placebo or historical controls, despite divergent study methodology and location. Importantly, the savings were evident in both larger (> or = 1250g) and smaller (700 to 1350g) infants. All studies considered costs or charges accrued during initial hospitalisation through to 1 year; measurement of long term resource use data and all resulting costs are required for a more complete pharmacoeconomic evaluation. The optimal timing of surfactant administration is likely to be an important economic issue given that efficacy data from a large international trial support earlier administration of colfosceril palmitate versus delayed therapy in high risk patients. Further economic benefits may be realised by the sequential use of antenatal corticosteroids and surfactant therapy, although this has yet to be prospectively investigated. In conclusion, clinical and pharmacoeconomic data strongly support the use of rescue therapy with colfosceril palmitate. Additionally, recent clinical data indicating that even better results may be achieved with earlier administration and/or combined use with antenatal corticosteroids should be assessed from an economic standpoint to determine the optimal prescribing strategy for this agent.

1,2-Dipalmitoylphosphatidylcholine↗

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

Cefetamet pivoxil. A review of its antibacterial activity, pharmacokinetic properties and therapeutic use.

Cefetamet pivoxil is an oral third-generation cephalosporin which is hydrolysed to form the active agent, cefetamet. Cefetamet has excellent in vitro activity against the major respiratory pathogens Streptococcus pneumoniae, Haemophilus influenzae, Moraxella (Branhamella) catarrhalis and group A beta-haemolytic streptococci; it is active against beta-lactamase-producing strains of H. influenzae and M. catarrhalis, but has poor activity against penicillin-resistant S. pneumoniae. Cefetamet has marked activity against Neisseria gonorrhoeae and possesses a broad spectrum of activity against Enterobacteriaceae. Both staphylococci and Pseudomonas spp. are resistant to cefetamet. Cefetamet pivoxil has been investigated in the treatment of both upper and lower community-acquired respiratory tract infections and has demonstrated equivalent efficacy to a number of more established agents, namely cefaclor, amoxicillin and cefixime. In patients with group A beta-haemolytic streptococcal pharyngotonsillitis, a 7-day course of cefetamet pivoxil was as effective as a 10-day course of the standard agent, phenoxymethylpenicillin, in this indication. In complicated urinary tract infections, cefetamet pivoxil showed similar efficacy to cefadroxil, cefaclor and cefuroxime axetil. Cefetamet pivoxil was effective in the treatment of otitis media, pneumonia, pharyngotonsillitis and urinary tract infections in children. Preliminary data indicate that single dose cefetamet pivoxil can effectively eradicate N. gonorrhoeae from both men and women. Cefetamet pivoxil has a tolerability profile similar to that of other oral cephalosporins, with gastrointestinal effects being the most commonly reported adverse events. To date, no symptoms of carnitine deficiency have been reported with cefetamet pivoxil. Cefetamet pivoxil offers effective alternative oral therapy for outpatient treatment of community-acquired respiratory tract infections, with the advantage of improved activity against H. influenzae and increased beta-lactamase stability. However, its use in areas with a high incidence of penicillin-resistant S. pneumoniae is likely to be limited. Cefetamet pivoxil is also effective in the treatment of urinary tract infections, although further trials are required to define any comparative advantages over other oral agents.

Bacteria↗