Evaluation of the activities of two-drug combinations of rifampicin, polymyxin B and ampicillin/sulbactam against Acinetobacter baumannii.
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Publications and source records attributed to A Del Favero.
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During the 1995 Multinational Association of Supportive Care in Cancer (MASCC) Congress, a consensus conference was planned by the Subcommittee for Antiemetics. To define the topics to be discussed, a questionnaire containing both clinical and methodological issues was sent to 118 experts in 31 countries. The questionnaire contained 33 items on clinical and 19 items on methodological issues, and each response was rated on a 4-level categorical scale. The clinical issues were evaluated for interest, that is clinical importance, and feasibility, that is availability of sufficient data to make them suitable topics for the consensus conference. About 60% of questionnaires were returned, with a small number of missing responses. The responses to the items of clinical interest showed that about two-thirds of the issues identified by the Subcommittee were found by the experts to be of at least high interest, but often the availability of data was found to be insufficient for their discussion. Prevention of acute emesis induced by cisplatin and by moderately emetogenic chemotherapy and the optimal intravenous dose and schedule of the 5-HT3 receptor antagonists were the items with the highest interest and feasibility. The issues in the methodological section were also mostly found to be of at least high interest. The distinction between acute and delayed emesis, the evaluation of the persistence of antiemetic efficacy in subsequent cycles of chemotherapy and the statistical analysis of delayed emesis were the methodological issues in which the highest interest was recorded. Data collected will be used to define the main topics to be discussed during the planned consensus conference.
Differences among 5-HT3 receptor antagonists have been reported in pharmacological studies with regard to selectivity of receptor binding, potency, duration of action and dose-response curves. However, whether these pharmacological differences can affect clinical efficacy and safety remains to be determined. A careful analysis of the literature revealed 22 comparative studies among the 5-HT3 receptor antagonists available for review. Unfortunately, several of these trials have some important shortcomings especially in the study design, the size of population studied and the type of anti-emetic treatment selected, making their conclusions often difficult to interpret. However, among these studies, seven large, double-blind clinical trials have clearly shown that the antiemetic activity and tolerability of ondansetron, granisetron, tropisetron and dolasetron is almost identical at least in the prevention of cisplatin-induced emesis. Therefore, from the efficacy and safety point of view, there is no reason to prefer one with respect to the other compound. From the economic perspective, instead, differences may exist and they are strictly related to the dose and schedule of administration chosen for each compound. The information available on the use of 5-HT3 receptor antagonists in the prevention of emesis induced by moderately emetogenic chemotherapy is at best scant. Contrasting results have been reported and only one well-conducted study has been published in full. Therefore, the possible differences among the various compounds are difficult to evaluate. More studies should be carried out in this group of patients.
A retrospective study of 37 patients with haematological malignancy (21 acute myeloid leukaemia, 11 acute lymphoid leukaemia, two lymphoma, two hairy cell leukaemia, one Hodgkin's disease) and histologically documented mucormycosis was conducted to evaluate the clinical characteristics and ascertain the factors which influenced the outcome from mycotic infection. Patients were admitted to 18 haematology divisions in tertiary care or university hospitals in Italy between 1987 and 1995. Fever, thoracic pain, dyspnoea and cough were the most frequent presenting symptoms. At the onset, 89% patients were neutropenic (neutrophil counts < 0.5 x 10(9)/l) with a median duration of previous neutropenia of 14 d (range 6-60). The most frequent sites of infection were lungs (81%), CNS (27%), sinus (16%), liver (16%) and orbital space (10%). Only three patients were asymptomatic. A correct in vivo diagnosis was made in only 13 (35%) patients. When performed, thoracic and cranial CT scan were the most useful diagnostic investigations. Despite the fact that 26 febrile patients were treated with empirical antifungal treatment, 28 of the 37 patients (76%) died from fungal infection at a median time of 17 d from the onset of clinical symptoms. Nine patients were cured by antifungal therapy plus, in five cases, radical surgery procedures. An analysis of factors influencing outcome demonstrated that the resolution of chemotherapy-induced neutropenia and prolonged treatment with amphotericin B and, if feasible, radical surgical debridement treatment, were significantly correlated with recovery from infection. Mucormycosis, a rare filamentous fungal infection that occurs most frequently in neutropenic acute leukaemia patients, is characterized by a high mortality rate. Extensive and aggressive diagnostic and therapeutic procedures are essential to improve the prognosis in these patients.
In the past few years a combination of a 5-HT3 receptor antagonist plus dexamethasone has been shown to be the most efficacious antiemetic prophylaxis of acute emesis induced by cisplatin and moderately emetogenic chemotherapy. In the prevention of cisplatin-induced delayed emesis oral metoclopramide or ondansetron, both combined with dexamethasone, offer similar antiemetic protection. Due to its lower cost the metoclopramide regimen remains the treatment of choice, whereas the ondansetron one is a valid alternative treatment that may be preferred in patients who present acute emesis. In the prevention of delayed emesis induced by moderately emetogenic chemotherapy ondansetron and dexamethasone have been shown superior to placebo. On the other hand, a recent observational study suggested that patients presenting acute vomiting or acute moderate-severe nausea, having a high incidence of delayed emesis, should always receive antiemetic prophylaxis. Instead, patients obtaining complete protection from acute emesis may not require any antiemetic prophylaxis.
Since 1981, when high-dose intravenous metoclopramide was demonstrated to be efficacious, slow but constant improvement in the prevention of chemotherapy-induced emesis has been achieved. Today, a combination of a serotonin receptor 3 (5-HT3) antagonist plus dexamethasone can be considered the most efficacious treatment for the prevention of emesis induced by cisplatin and by moderately emetogenic chemotherapy. Which 5-HT3receptor antagonist should be used? Preclinical differences among 5-HT3receptor antagonists have been reported with regard to selectivity of receptor binding, potency, dose response, and duration of action. Twelve comparative studies among 5-HT3receptor antagonists have been carried out. Unfortunately, all these trials have some important shortcomings (patient population not large enough to show small but clinically important differences; not blinded studies; no association with steroids to maximize treatment efficacy) and, therefore, no definitive conclusions can be drawn. Very recently three large, well-conducted double-blind comparative studies have been published. All three showed that 5-HT3receptor antagonists have almost identical antiemetic efficacy and tolerability. Therefore, the choice among the 5-HT3receptor antagonists should be based only on the acquisition cost of the prescribed dose in each country for each compound.
Chemotherapy-induced nausea and vomiting can today be controlled with the "new" antiemetics or with their various combinations in a high percentage of patients. Despite this, for some subgroups of patients, certain chemotherapy regimens and some aspects of the phenomenon (delayed presentation), emesis remains a critical problem. Hence, there is the necessity for a continuous effort in the search for new drugs or better treatment modalities and the absolute requisite that these efforts be carried out according to a sound and verified trial methodology. Nausea and vomiting induced by antineoplastic agents are extremely variable phenomena, depending not only on the characteristics of chemotherapy regimens and of the patient population, but also on a subjective feeling generated by the impact of the care system on the patient's individual situation. Therefore, precisely because of this high variability, large comparative trials should be carried out to ensure that the sample is sufficiently representative for the most efficacious antiemetic regimen to be detected. In this field, some of the main problems arising in all clinical trials have their own specificity, particularly the study design, whether completely randomized or cross-over, the follow-up and the importance of prognostic factors. Among these, age, gender and previous chemotherapy with experience of nausea and vomiting have been confirmed as important. In addition, some topics must clearly be highlighted: the definition of the response variables and the assessment of variability of the results obtained with the same antiemetic regimen from one cycle of chemotherapy to the next (i.e. persistence). The greater attention devoted today to delayed emesis raises some methodological questions: this paper suggests some possible solutions for a better evaluation of this phenomenon.
This multicentre, randomised, double-blind study was designed to compare the anti-emetic efficacy and safety of single oral doses of dolasetron mesilate with that of the approved oral, multiple-dose regimen of ondansetron in 399 cancer patients receiving moderately emetogenic chemotherapy. Single oral doses of 25, 50, 100 or 200 mg of dolasetron mesilate were administered 1 h prior to the initiation of moderately emetogenic chemotherapy. Multiple doses of ondansetron (8 mg x 3 or 8 mg x 4) capsules, or matching placebo for patients randomised to dolasetron, were given 1.5 h before and 6.5, 14.5 and 22.5 h after the start of chemotherapy (total dose = 32 mg). Efficacy was evaluated for 24 h after the initiation of chemotherapy. The most frequently used moderately emetogenic chemotherapeutic agents included cyclophosphamide, doxorubicin and carboplatin (28.4, 23.1 and 20.6% of patients, respectively). A statistically significant (P < 0.001) linear dose-response relationship was observed over the entire dolasetron dosage range for all efficacy parameters. Complete response rates were 45.0, 49.4, 60.5 and 76.3% for 25, 50, 100 and 200 mg dolasetron mesilate, respectively, and 72.3% of ondansetron patients. A single oral 200 mg dolasetron mesilate dose was therapeutically equivalent to ondansetron for all efficacy parameters and patient satisfaction was high. Overall, there were no significant differences in the incidence of adverse events between any of the dolasetron mesilate doses, or between dolasetron and ondansetron. Headache was most frequently reported (approximately 15% for each drug). No clinically important changes in vital signs or clinical laboratory parameters were observed with either drug. In conclusion, a single oral 200 mg dolasetron mesilate dose was therapeutically equivalent to multiple-dose ondansetron in the prevention of emesis and nausea following moderately emetogenic chemotherapy.
We retrospectively studied a consecutive series of 100 patients with acute leukemia and aspergillosis to evaluate the clinical findings and risk factors for colonization of the central nervous system (CNS) by Aspergillus species. The diagnosis of CNS aspergillosis was made in 14 patients on the basis of the following criteria: neurological signs of CNS involvement (13 of 14 patients); cerebral CT scan findings (9 of 12); microbiological findings (6 of 12); and histological findings at autopsy (11 of 11). The majority of patients had severe neurological complications (i.e., hemiparesis or seizures), due mainly to brain abscesses or mycetomas. Autopsies were performed on 11 of 14 patients and provided evidence that CNS localization was secondary to invasive aspergillosis; in each case, the most likely primary focus of infection was the lung. Although all patients had received oral antimycotic prophylaxis and had received timely empirical antifungal treatment, they all died within a median time of 5 days from the onset of neurological symptoms. Analysis of the characteristics of patients with invasive aspergillosis did not reveal any difference between those with CNS localization and those without CNS localization.
Combinations of beta-lactams plus aminoglycosides have been standard therapy for suspected infections in granulocytopenic cancer patients, especially those with profound long-lasting granulocytopenia. With the advent of new broad-spectrum bactericidal antibiotics such as extended-spectrum cephalosporins or carbapenems, the need to combine beta-lactams with aminoglycosides became more controversial. The objective of this prospective randomized multicenter study was to compare the efficacy, safety, and tolerance of meropenem monotherapy with those of the combination of ceftazidime plus amikacin for the empirical treatment of fever in granulocytopenic cancer patients. Of 1,034 randomized patients, 958 were assessable in the intent-to-treat analysis for response to antibacterial therapy, including 483 in the meropenem group and 475 in the ceftazidime-plus-amikacin group. The median durations of neutropenia were 16 and 17 days, respectively. A successful outcome was reported in 270 of 483 (56%) patients treated with monotherapy compared with 245 of 475 (52%) patients treated with the combination group (P = 0.20). The success rates in the monotherapy group and the combination group were similar by type of infection (single gram-negative bacteremia, single gram-positive bacteremia, clinically documented infection, and possible infection). The occurrence of further infections assessed in patients for whom the allocated regimen was not modified did not differ between the two groups (12% in both groups). Mortality due to the presenting infection or further infection was relatively low (8 patients treated with the monotherapy compared with 13 patients treated with the combination). A total of 1,027 patients were evaluable for adverse events; the proportion of those who developed adverse effects was similar between the two groups (29% in both groups), and only 19 (4%) patients in the monotherapy group and 31 (6%) in the combination group experienced an adverse event related or probably related to the study drug. Allergic reactions were the only reason for stopping the protocol antibiotic(s) (3 and 5 patients, respectively). This study confirms that monotherapy with meropenem is as effective as the combination of ceftazidime plus amikacin for the empiric treatment of fever in persistently granulocytopenic cancer patients, and both regimens were well tolerated.
Ondansetron is a potent and highly selective serotonin 5-HT3-receptor antagonist which has demonstrated important antiemetic activity and good tolerability in the prevention of chemotherapy-induced nausea and vomiting. Ondansetron is completely and rapidly absorbed from the gastrointestinal tract after oral administration, and does not accumulate with repeated oral administration. Owing to hepatic first-pass metabolism, its bioavailability is only about 60% compared with ondansetron administered by infusion over 15 minutes. Bioavailability is slightly increased when administered after a standard meal, and is not influenced by coadministration of antacids; a slightly enhanced bioavailability has been observed in patients with cancer. Since the time to reach peak concentration is 0.5 to 2 hours after oral ingestion, the drug should be administered at least 30 minutes before chemotherapy. Possible alternative ways of administration of ondansetron include intramuscular, subcutaneous and rectal administration, and oral controlled-release formulations. Ondansetron is widely distributed (volume of distribution approximately 160L) and binds moderately (70 to 76%) to plasma proteins; the elimination half-life averages approximately 3.8 +/- 1 hours. Clearance occurs by hepatic metabolism (95%) rather than renal excretion. Metabolites do not play a role in the activity of the drug, and there is no evidence of genetic polymorphic metabolism. Although aging is associated with decreased clearance and increased bioavailability, dosage adjustments are not required for the elderly, and may be necessary only in patients with severe hepatic impairment. Chemotherapeutic agents do not seem to modify the pharmacokinetics of ondansetron. There remains the question of whether control of emesis is related to systemic availability of ondansetron and, in consequence, the optimal dose and schedule of ondansetron is still to be identified with certainty.
Infection remains the major cause of morbidity and mortality for cancer patients who become granulocytopenic as a result of chemotherapy. Treatment is instituted at the first sign of infection and before the identification of the causative pathogen (empiric treatment). For many years, standard empiric treatment has been combination therapy with beta-lactams and aminoglycosides. The advent of new broad spectrum antibiotics, such as ceftazidime, has introduced the possibility of empiric monotherapy. However, ceftazidime has only modest activity against infections due to Gram-positive organisms, which presently account for at least 50% of infections in neutropenic patients, and resistance to ceftazidime in Gram-negative organisms has been documented. Meropenem is a new carbapenem with a broad antibacterial spectrum with greater in vitro activity than ceftazidime against staphylococci, streptococci and many Gram-negative bacteria. A comparative study of intravenous meropenem (1 g 8-hourly) and ceftazidime (2 g 8-hourly) in the empiric treatment of febrile neutropenic patients with haematological malignancies has been conducted. In an open, randomised trial of the treatment of 338 febrile episodes, all patients survived to 72 hours on both treatments, and meropenem was found to be at least as clinically effective as ceftazidime in eradicating both Gram-positive and Gram-negative infections. Early modification of treatment (48-72 hours) was required for approximately 40% of patients but occurred less frequently in patients treated with meropenem than with ceftazidime. Tolerability of both treatments was good. Meropenem should be compared with standard combination therapy in a large randomised trial before adopting it as empiric monotherapy for febrile neutropenic patients.
OBJECTIVE: To compare the efficacy and tolerability of fluconazole and oral amphotericin B in preventing fungal infection in neutropenic patients with acute leukemia. DESIGN: A randomized, controlled, multicenter trial. SETTING: 30 hematologic units in tertiary care or university hospitals. PATIENTS: 820 consecutive, afebrile, adult patients with acute leukemia and chemotherapy-induced neutropenia. INTERVENTION: Patients were randomly assigned to receive fluconazole, 150 mg, as a once-daily capsule, or amphotericin B suspension, 500 mg every 6 hours. MEASUREMENTS: An intention-to-treat analysis was done for 820 patients: 420 treated with fluconazole and 400 treated with oral amphotericin B. RESULTS: Definite systemic fungal infection occurred in 2.6% of fluconazole recipients and 2.5% of amphotericin B recipients; suspected systemic fungal infection requiring the empiric use of intravenous amphotericin B occurred in 16% of fluconazole recipients and 21% of oral amphotericin B recipients, a difference of 5 percentage points (95% CI for difference, -0.02% to 10%; P = 0.07). Superficial fungal infection was documented in 1.7% of fluconazole recipients compared with 2.7% of amphotericin B recipients, a difference of one percentage point (CI of difference, -0.9% to 3%; P > 0.2). The distribution of fungal isolates in systemic and superficial fungal infection was similar in both groups. The overall mortality rate accounted for 10% in both groups. An excellent compliance was documented for 90% of patients treated with fluconazole compared with 72% of those treated with amphotericin B suspension, a difference of 18 percentage points (CI for difference, 13% to 23%). Side effects were documented less frequently in fluconazole than in amphotericin B recipients (1.4% compared with 7%, a difference of 5.6 percentage points; CI for difference, 2% to 8%; P < 0.01). CONCLUSION: Fluconazole was at least as effective as oral amphotericin B in preventing systemic and superficial fungal infection and the empiric use of amphotericin B in neutropenic patients with acute leukemia but was better tolerated.
The serotonin-receptor (5-HT3) antagonists combined with dexamethasone are considered the antiemetic therapy of choice in the prevention of cisplatin-induced emesis. As there are now several compounds on the market, the dilemma of preference is particularly relevant. In preclinical studies some differences among the three marketed drugs (ondansetron, granisetron and tropisetron) have emerged. In particular, tropisetron and granisetron have a greater potency and duration of action and seem to have a greater selectivity toward the 5-HT3 receptor with respect to ondansetron. Furthermore, while with tropisetron and granisetron there is a linear dose/response relationship, this does not seem to be the case for ondansetron. These preclinical differences, however, do not seem to correlate with the clinical antiemetic activity of these compounds. In fact, although the number of comparative studies is small, with all of them presenting several shortcomings (small number of patients, not blinded studies, no association with steroids, sponsored trials), it seems that the antiemetic activity and tolerability of ondansetron, granisetron and tropisetron is very similar. If these data are confirmed, the least expensive of the 5-HT3 antagonists should be the drug of choice. We feel, however, that the answer to this rather difficult question of choice will come from very large, independent, methodologically correct studies designed to show small but clinically significant differences (i.e., less than 10% in complete protection from emesis). These trials, which require about 1000-1500 patients, are ongoing and the one carried out as a multicenter study by the Italian Group for Antiemetic Research is close to conclusion.
Chemotherapy-related nausea and vomiting can today be controlled with available antiemetics in a high percentage of patients but emesis remains a problem for some patients, with certain drugs and with repeated cycles of chemotherapy. The fundamental steps of clinical research in antiemetics towards the improvement of the control of nausea and vomiting with new drugs or combinations are presented. Special emphasis is given to cisplatin-induced nausea and vomiting because of the frequency and relevance of this phenomenon. The use of high-dose metoclopramide, its combination with steroids, and later the addition of lorazepam or diphenhydramine represented the evolving standard of the 1980s, with the level of complete protection from vomiting improving from 30%-40% to 60%-70% with the three-drug combination. The introduction of new agents such as the 5-hydroxytryptamine 3 (5-HT3) receptor antagonists has recently offered new possibilities because of their activity and lack of toxicity. In particular, the combination of ondansetron plus dexamethasone is today the most efficacious and least toxic antiemetic treatment for prevention of emesis in patients treated with a single high dose or low repeated doses of cisplatin. A comparison of different 5-HT3 antagonists, always in combination with steroids, is now considered necessary. For patients treated with moderately emetogenic chemotherapy the use of steroids can still be considered the standard treatment. In this setting, the role of 5-HT3 receptor antagonists, alone or in combination with steroids, has to be better defined through large, well-planned clinical trials, which should have a cost-effectiveness analysis as one of their goals.
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In a large double-blind study of antiemetic therapy conducted in Italy, 289 patients underwent 3 consecutive cycles of cisplatin chemotherapy. Antiemetic treatment with ondansetron plus dexamethasone was more efficacious and better tolerated, but also more expensive, than treatment with metoclopramide plus both dexamethasone and diphenhydramine. To evaluate the different costs of the 2 antiemetic regimens, we conducted a retrospective cost-effectiveness analysis from a hospital perspective. Direct costs of antiemetic therapy (acquisition cost of drugs, materials and time spent by nurses to prepare and administer therapies), cleanup after emesis, rescue medication and adverse events were evaluated. Antiemetic drug acquisition costs per patient were 5.23-fold higher for the ondansetron regimen than for the metoclopramide regimen. However, when the costs of materials and nursing time required to prepare and administer the antiemetic regimens were included, this ratio was 3.77. Furthermore, including the cost of emesis, rescue antiemetic treatments and medication used to treat adverse events, hospital costs per patient were 3.21-fold higher with the ondansetron regimen during the first cycle, 3.08-fold higher during second cycle and 2.89-fold higher during third cycle of chemotherapy. Complete protection from vomiting and from both vomiting and nausea with ondansetron occurred, respectively, in 78.7 and 69.1% of patients in the first cycle, 73.8 and 57.3% in the second cycle, and 74.2 and 58.1% in third cycle of chemotherapy. Corresponding figures for the metoclopramide regimen were 59.5 and 50.4%, 53.6 and 37.1%, and 46.8 and 27.3%, respectively. Thus, the cost per successfully treated (completely protected) patient was 2.43- and 2.34-fold higher, respectively, for ondansetron at the first cycle, 2.23- and 1.99-fold higher, respectively, at second cycle, and 1.82- and 1.36-fold higher, respectively, at third cycle. In conclusion, the study demonstrates that, while ondansetron has a greater acquisition cost than metoclopramide, the ondansetron regimen costs per successfully-treated patient substantially decrease when all direct hospital costs are taken into account.