Oral granisetron--simple and effective: a preliminary report. The Granisetron Study Group

[Management of chemotherapy-induced emesis: what is the standard after 20 years of clinical research]

BACKGROUND

The knowledge of the importance, the physiopathological mechanisms, and the management of the chemotherapy-induced emesis has increased exponentially during the last 20 years. High-dosage metoclopramide (MCP) therapy has been introduced in the eighties and serotonine type-3 receptor antagonists (5-HT(3) antagonists) have been used since the late eighties and early nineties. Due to both classes of substances the results of the antiemetic therapies have improved drastically. After 20 years of intensive clinical research it seems to be appropriate to come to an intermediate conclusion.

METHOD

With the aid of an overview and a new analysis of the literature published on this topic so far, the current state of research is shown (including the fields in which further improvement will be necessary), and suggestions are made, wherever it seemed possible, to attain the "gold standard" in antiemetic therapy.

RESULTS AND CONCLUSIONS

In connection with all highly or very highly emetogenic chemotherapies, an antiemetic prophylaxis should be initiated on the day of therapy, especially when using platinum or most of the cyclophosphamide-based regimes for cancer treatment. The recommended prophylaxis consists of a combination of 5-HT(3) antagonists with a corticosteroid. To combat the so-called delayed emesis on the days following therapy, all patients should undergo an oral corticoid therapy, possibly in combination with MCP (especially platinum-therapy patients), less frequently with 5-HT(3) antagonists. With these means of prophylaxis emesis can be prevented/avoided completely in most patients, and nausea can at least be reduced. It is sufficient to administer a single dose of 5-HT(3) antagonists prior to chemotherapy. For ondansetron and granisetron, the best documented substances within this class of drugs, 8 mg (ondansteron) and 3 mg (granisetron) are considered standard dosages. Among the corticoids, most data have been accumulated for dexamethasone. A standard dose of 10 to 20 mg can be administered prior to chemotherapy. Right after and especially on the days following chemotherapy higher dosages seem to be indicated.

PROSPECT

Further therapy improvements, especially concerning emesis and nausea on the days following chemotherapy, are necessary and are currently object of clinical research.

5-hydroxytryptamine type-3 receptor antagonists for chemotherapy-induced and radiotherapy-induced nausea and emesis: can we safely reduce the dose of administered agents?

BACKGROUND

Nausea and emesis as a consequence of chemotherapy or radiotherapy can have an adverse effect on patients' quality of life during cancer treatment and may last for > 5 days after administration. Guidelines suggest that, used at appropriate doses, the 5-hydroxytryptamine type-3 (5-HT3) receptor antagonists--which are considered the antiemetic "gold standard" when they are administered in combination with corticosteroids--demonstrate equivalent efficacy and safety. However, due to financial considerations, these agents often are used at lower doses than recommended.

METHODS

A literature review of relevant publications pertaining to the control of chemotherapy-induced nausea and emesis and dosing issues of the 5-HT3 receptor antagonists was undertaken to provide a comprehensive review of dosing issues relevant to the 5-HT3 receptor antagonists.

RESULTS

The issue of "down dosing" was particularly pertinent because of the nature of the 5-HT3 receptor antagonist dose-response curve: A steep dose-response profile within a narrow dose range suggests that antiemetic control will be lost suddenly after dose deescalation. However, the array of predisposing and confounding patient factors indicates that it is unlikely that a loss of antiemetic control will be apparent across a population; rather, individuals will experience loss of control as the dose is reduced below threshold. Of the 4 5-HT3 receptor antagonists currently licensed in the United States (granisetron, ondansetron, dolasetron, and palonosetron), ondansetron is used sometimes at lower than optimal doses, and there is evidence to suggest that even the approved oral dose of dolasetron may be suboptimal.

CONCLUSIONS

Suboptimal dosing not only will be detrimental to patients' quality of life but, ultimately, will prove counterproductive in terms of hospital resources, and it will add to the already significant socioeconomic burden associated with cancer therapy. Therefore, the dose of antiemetic agent administered should be sufficiently high to ensure good emesis control across the whole patient population.

Preoperative oral granisetron for the prevention of vomiting following paediatric surgery

BACKGROUND

We evaluated the efficacy of granisetron, 5-hydroxytryptamine type 3 receptor antagonist, given orally, preoperatively, for the prevention of postoperative vomiting in children undergoing general anaesthesia for surgery (inguinal hernia, phimosis-circumcision).

METHODS

In a randomized, double-blinded manner, 100 children, ASA physical status I, aged 4-11 years, received orally placebo or granisetron at three different doses (20 microg x kg(-1), 40 microg x kg(-1), 80 microg x kg(-1)) 60 min before surgery (n=25 of each). The same standard general anaesthetic technique was used.

RESULTS

The percentage of patients being emesis-free during 0-6 h after anaesthesia was 56% with placebo, 64% with graniseron 20 microg x kg(-1) (P=0.773), 88% with granisetron 40 microg x kg(-1) (P=0.027) and 92% with granisetron 80 microg x kg(-1) (P=0.01); the corresponding rate during 6-24 h after anaesthesia was 60%, 68% (P=0.768), 92% (P=0.02) and 92% (P=0.02) (P-values versus placebo). No clinically serious adverse events were observed in any of the groups.

CONCLUSIONS

In summary, preoperative oral granisetron 40 microg x kg(-1) is effective for the prevention of vomiting following paediatric surgery (inguinal hernia, phimosis-circumcision). Increasing the doses to 80 microg x kg(-1) provides no demonstrable additional benefit.

Preoperative oral granisetron for the prevention of vomiting after strabismus surgery in children

OBJECTIVE

To evaluate the efficacy of oral granisetron for the prevention of postoperative vomiting in children undergoing strabismus surgery.

DESIGN

Prospective, randomized, double-masked, placebo-controlled study.

PARTICIPANTS

A total of 120 children, 4-10 years of age, scheduled for elective strabismus surgery.

INTERVENTION

Patients received oral placebo or granisetron at three different doses (20 microg/kg, 40 microg/kg, 80 microg/kg) 1 hour before surgery.

MAIN OUTCOME MEASURES

A complete response, defined as no vomiting, no retching, and no need for rescue antiemetic medication, during the first 24 hours after anesthesia was recorded.

RESULTS

A complete response during 0-24 hours after anesthesia occurred in 33% of those who received placebo, 40% who received granisetron 20 microg/kg, 83% who received granisetron 40 microg/kg, and 87% who received granisetron 80 microg/kg (P < 0.05, overall Fisher's exact probability test).

CONCLUSION

Preoperative oral granisetron, in doses more than 40 microg/kg, is effective for preventing vomiting after strabismus surgery in children.

Preoperative oral granisetron prevents postoperative nausea and vomiting

BACKGROUND

Postoperative nausea and vomiting (PONV) is a commonly observed adverse effect of anaesthesia. This study was designed to evaluate the efficacy of granisetron administered orally for preventing PONV in female patients undergoing major gynaecological surgery.

METHODS

In a prospective, randomized, placebo-controlled, double-blind study, 120 patients received orally either placebo or granisetron (1 mg, 2 mg or 4 mg) (n = 30 for each) 1 h before surgery. The same standard general plus regional anaesthetic technique was employed throughout. Postoperatively, during the first 24 h after anaesthesia, the incidence of PONV and adverse events was recorded by nursing staff.

RESULTS

The incidence of PONV was 47% with placebo, 37% with granisetron 1 mg, 10% with granisetron 2 mg and 10% with granisetron 4 mg (P < 0.05; overall Fisher's exact probability test). No difference in the incidence of adverse events was observed among the groups.

CONCLUSION

Preoperative oral granisetron in a minimum dose of 2 mg is effective for preventing PONV after major gynaecological surgery.

Anemia and fatigue in cancer patients

Although strong evidence indicates that fatigue can be caused by anemia, little is known about the relationship between the extent and rate of hemoglobin loss and the development of fa tigue. Anemia, an insufficiency of red blood cells to maintain adequate tissue oxygenation, is the most common hematologic abnormality associ ated with cancer. It usually results from a de crease in red blood cell production, resulting from either direct tumor invasion of bone mar row or the anemia of chronic disease. Fatigue is a subjective sensation, often described as tired ness, exhaustion, lethargy, or malaise. The mechanism that precipitates or sustains fatigue is probably multifactorial and includes the re lease of inflammatory cytokines and the onset of the acute-phase inflammatory response. Other factors that contribute to cancer-related fatigue include the underlying disease, treatment of the disease, intercurrent systemic illnesses, sleep disorders, immobility and lack of exercise, chronic pain, and psychosocial factors. A review of cancer-related anemia and fatigue is pre sented, which focuses on the clinical decision- making process regarding the management of these syndromes when they exist concurrently.

Comparative studies of various antiemetic regimens

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.

Comparative efficacy of oral and intravenous granisetron for the prevention of acute chemotherapy-induced emesis

Intravenous 5-hydroxytryptamine3 (5-HT3) receptor antagonists are now established antiemetics in the treatment of chemotherapy-induced emesis. For optimal convenience and acceptability, oral therapy is desirable. Retrospective comparisons indicate that oral granisetron may have an efficacy comparable with that of intravenous granisetron. Recent new data are available on the use of granisetron in the prophylaxis of acute emesis in randomized, double-masked trials. After moderately emetogenic chemotherapy, the optimal regimen appears to be 1 mg twice daily, although 2 mg once daily is equally effective. Oral granisetron is significantly superior to oral prochlorperazine. After high-dose cisplatin chemotherapy, oral granisetron is as effective as metoclopramide plus dexamethasone; the addition of dexamethasone further enhances its efficacy. Oral granisetron was well tolerated in all these trials. Headache and constipation were the most common adverse events, as has been reported for other 5-HT3 receptor antagonists. No randomized trials of oral-only tropisetron or dolasetron have yet been published.

Antiemetic treatment with oral granisetron in patients receiving moderately emetogenic chemotherapy: a dose-ranging study

The antiemetic efficacy and tolerability of four different oral doses of granisetron (0.25, 0.5, 1, and 2 mg twice daily [BID]) were compared in a randomized, double-blind, parallel-group, multicenter study involving 930 patients with malignant disease receiving moderately emetogenic chemotherapy over a 7- or 14-day period. On the first day of granisetron treatment, a statistically significant association between complete response and dose was seen (P = 0.001), with the maximum response (81.1%) achieved at a dose of 1 mg BID. The 24-hour complete response rate with granisetron 1 mg BID was significantly higher than with 0.25 mg BID (61.1%) or 0.5 mg BID (70.2%) (P < 0.009). The complete response rate for days 0 to 6 was significantly higher with granisetron at 1 mg BID (58.8%) than with 0.25 mg BID (43.7%) or 0.5 mg BID (53.6%) (P < 0.009). No advantage in terms of complete response rate was shown for 2 mg BID over 1 mg BID. Granisetron was well tolerated, and few patients required additional treatment with other antiemetics.

Oral granisetron alone and in combination with dexamethasone: a double-blind randomized comparison against high-dose metoclopramide plus dexamethasone in prevention of cisplatin-induced emesis. The Granisetron Study Group

PATIENTS AND METHODS

Three anti-emetic treatment regimens were compared in 357 patients receiving cisplatin therapy (mean dose 81 mg/m2) in this double-blind randomized study. Regimens studied were i) granisetron 1 mg bd orally for 7 days (granisetron alone); ii) gran 1 mg bd orally for 7 days plus prophylactic dexamethasone (12 mg i.v.) on the first day only (gran/dex); iii) metoclopramide (3 mg/kg i.v. loading dose; 4 mg/kg i.v. infusion) plus dex (12 mg i.v.) on the first day followed by met 10 mg orally tds for a further 6 days (met/dex).

RESULTS

At 24 hours, gran/dex was significantly superior to met/dex in terms of total anti-emetic control, defined as no nausea, no vomiting, no rescue anti-emetic therapy, not withdrawn (54.7% gran/dex vs. 37.2% met/dex; P < 0.01). There was also a significant delay in time to onset of nausea (P < 0.01) and vomiting (P < 0.01) following gran/dex compared with met/dex. Oral granisetron alone was as effective as met/dex in control of acute emesis in all parameters examined. There were no significant differences between the three groups in the control of delayed nausea and vomiting. The most common adverse experiences in both granisetron groups were headache and constipation, both characteristic of 5-HT3 antagonists. Agitation, somnolence, diarrhoea and decreased appetite were reported more frequently by the met/dex group.

CONCLUSIONS

Oral granisetron as a single agent is as effective as high doses of i.v. met/dex in preventing cisplatin-induced emesis. Oral granisetron in combination with a corticosteroid provides superior anti-emetic control to the met/dex regimen in patients undergoing highly emetogenic chemotherapy.

Cancer therapy-induced emesis: the nurse's perspective

There have been significant improvements in the diagnosis and treatment of malignant tumours. However, recent advances in cytostatic therapy are associated with several adverse side-effects which can impair the patient's well-being and may result in refusal or delay of treatment. Nausea and vomiting are perceived to be the most unpleasant of these side-effects. This paper addresses some of the issues involved in the improvement of these two distressing symptoms.

[Antiemetic treatment and chemotherapy: general review]

Chemotherapy-induced nausea and emesis are frequent and patients fearful. Emesis caused by cytotoxic agents can be related to their effects on central chemoreceptor or on the gut chemoreceptor by serotonin. 5HT3 receptor antagonists produce a major improvement in the control of cisplatin induced-emesis (70 to 80% of patients). The 5HT3-antagonist efficacy is significantly better than metoclopramide alone, or antimemetic combinations in highly emetogenic chemotherapy regimens but less good in moderately emetogenic chemotherapy. Studies with 5HT3 receptor antagonist plus corticosteroids show advantage over 5HT3 antagonist alone. Comparison studies between the different setrons didn't show any significant difference. Anticipary emesis are treated with anxiolytic drugs. The prevention of delayed emesis, not yet well controlled by 5HT3 antagonist, is a great therapeutic deal. Finally, some therapeutic problems are not resolved: minimal dose, use of oral route, efficacy in fractionated chemotherapy, treatment after loss of efficacy of 5HT3 antagonist.