Adult Patients

The recommended dosage for granisetron hydrochloride injection USP is 10 mcg/kg administered intravenously within 30 minutes before initiation of chemotherapy, and only on the day(s) chemotherapy is given.

Infusion Preparation
Granisetron hydrochloride injection USP may be administered intravenously either undiluted over 30 seconds, or diluted with 0.9% Sodium Chloride or 5% Dextrose and infused over 5 minutes.

Stability
Intravenous infusion of granisetron hydrochloride injection USP should be prepared at the time of administration. However, granisetron hydrochloride injection USP has been shown to be stable for at least 24 hours when diluted in 0.9% Sodium Chloride or 5% Dextrose and stored at room temperature under normal lighting conditions.
As a general precaution, granisetron hydrochloride injection USP should not be mixed in solution with other drugs. Parenteral drug products should be inspected visually for particulate matter and discoloration before administration whenever solution and container permit.

Pediatric Patients
The recommended dose in pediatric patients 2 to 16 years of age is 10 mcg/kg [see Clinical Studies (14)]. Pediatric patients under 2 years of age have not been studied.

Chemotherapy-Induced Nausea and Vomiting

The following have been reported during controlled clinical trials or in the routine management of patients. The percentage figures are based on clinical trial experience only. Table 1 gives the comparative frequencies of the two most commonly reported adverse reactions (≧3%) in patients receiving granisetron hydrochloride injection, in single-day chemotherapy trials. These patients received chemotherapy, primarily cisplatin, and intravenous fluids during the 24-hour period following granisetron hydrochloride injection administration. Reactions were generally recorded over seven days post-granisetron hydrochloride injection administration.

*Metoclopramide/dexamethasone and phenothiazines/dexamethasone.

Additional adverse events reported in clinical trials were asthenia, somnolence and diarrhea.

In over 3,000 patients receiving granisetron hydrochloride injection (2 to 160 mcg/kg) in single-day and multiple-day clinical trials with emetogenic cancer therapies, adverse events, other than those adverse reactions listed in Table 1, were observed; attribution of many of these events to granisetron hydrochloride is uncertain.

Hepatic: In comparative trials, mainly with cisplatin regimens, elevations of AST and ALT (>2 times the upper limit of normal) following administration of granisetron hydrochloride injection occurred in 2.8% and 3.3% of patients, respectively. These frequencies were not significantly different from those seen with comparators (AST: 2.1%; ALT: 2.4%).

Cardiovascular: Hypertension (2%); hypotension, arrhythmias such as sinus bradycardia, atrial fibrillation, varying degrees of A-V block, ventricular ectopy including non-sustained tachycardia, and ECG abnormalities have been observed rarely.

Central Nervous System: Agitation, anxiety, CNS stimulation and insomnia were seen in less than 2% of patients. Extrapyramidal syndrome occurred rarely and only in the presence of other drugs associated with this syndrome.

Hypersensitivity: Rare cases of hypersensitivity reactions, sometimes severe (eg, anaphylaxis, shortness of breath, hypotension, urticaria) have been reported.

Other: Fever (3%), taste disorder (2%), skin rashes (1%). In multiple-day comparative studies, fever occurred more frequently with granisetron hydrochloride injection (8.6%) than with comparative drugs (3.4%, P<0.014), which usually included dexamethasone.

Postoperative Nausea and Vomiting

The adverse reactions listed in Table 2 were reported in 2% of adults receiving Granisetron Hydrochloride Injection 1 mg during controlled clinical trials.

Additional adverse events reported in clinical trials were constipation, anemia, insomnia, bradycardia, leukocytosis, anxiety, hypotension, infection, hypertension, and urinary tract infection.

In a clinical study conducted in Japan, the types of adverse events differed notably from those reported above in Table 2. The adverse events in the Japanese study that occurred in 2% of patients and were more frequent with Granisetron Hydrochloride Injection 1 mg than with placebo were: fever (56% to 50%), sputum increased (2.7% to 1.7%), and dermatitis (2.7% to 0%).

Teratogenic Effects

Chemotherapy-Induced Nausea and Vomiting

[See Dosage and Administration (2)] for use in chemotherapy-induced nausea and vomiting in pediatric patients 2 to 16 years of age. Safety and effectiveness in pediatric patients under 2 years of age have not been established.

Postoperative Nausea and Vomiting
Safety and efficacy have not been established in pediatric patients for the prevention of postoperative nausea and vomiting (PONV). Granisetron has been evaluated in a pediatric patient clinical trial for use in the prevention of PONV. Due to the lack of efficacy and the QT prolongation observed in this trial, use of granisetron for the prevention of PONV in children is not recommended. The trial was a prospective, multicenter, randomized, doubleblind, parallel-group trial that evaluated 157 children aged 2 to 16 years who were undergoing elective surgery for tonsillectomy or adenotonsillectomy. The purpose of the trial was to assess two dose levels (20 mcg/kg and 40 mcg/kg) of intravenous granisetron in the prevention of PONV. There was no active comparator or placebo. The primary endpoint was total control of nausea and vomiting (defined as no nausea, vomiting/retching, or use of rescue medication) in the 24 hours following surgery. Efficacy was not established due to lack of a dose response.
The trial also included standard 12 lead ECGs performed pre-dose and after the induction of anesthesia. ECGs were repeated at the end of surgery after the administration of granisetron and just prior to reversal of anesthesia. QT prolongation was seen at both dose levels. Five patients in this trial experienced an increase of ≥ 60 msec in QTcF. In addition, there were two patients whose QTcF was ≥ 500 msec. Interpretation of the QTcF prolongation was confounded by multiple factors, including the use of concomitant medication and the lack of either a placebo or active control. A thorough QT trial in adults has not been performed.
Other adverse events that occurred in the study included: vomiting (5 to 8%), post-procedural hemorrhage (3 to 5%), and dehydration (0 to 5%).
Pediatric patients under 2 years of age have not been studied.

Chemotherapy-Induced Nausea and Vomiting

In adult cancer patients undergoing chemotherapy and in volunteers, mean pharmacokinetic data obtained from an infusion of a single 40 mcg/kg dose of granisetron hydrochloride injection are shown in Table 3.

*5-minute infusion.

†3-minute infusion.

Distribution

Plasma protein binding is approximately 65% and granisetron distributes freely between plasma and red blood cells.

Metabolism

Granisetron metabolism involves N-demethylation and aromatic ring oxidation followed by conjugation. In vitro liver microsomal studies show that granisetron's major route of metabolism is inhibited by ketoconazole, suggestive of metabolism mediated by the cytochrome P-450 3A subfamily. Animal studies suggest that some of the metabolites may also have 5-HT3 receptor antagonist activity.

Elimination

Clearance is predominantly by hepatic metabolism. In normal volunteers, approximately 12% of the administered dose is eliminated unchanged in the urine in 48 hours. The remainder of the dose is excreted as metabolites, 49% in the urine, and 34% in the feces.

Subpopulations

Postoperative Nausea and Vomiting

In adult patients (age range, 18 to 64 years) recovering from elective surgery and receiving general balanced anesthesia, mean pharmacokinetic data obtained from a single 1 mg dose of Granisetron Hydrochloride Injection administered intravenously over 30 seconds are shown in Table 4.

The pharmacokinetics of granisetron in patients undergoing surgery were similar to those seen in cancer patients undergoing chemotherapy.

Single-Day Chemotherapy

Cisplatin-Based Chemotherapy

In a double-blind, placebo-controlled study in 28 cancer patients, granisetron hydrochloride injection, administered as a single intravenous infusion of 40 mcg/kg, was significantly more effective than placebo in preventing nausea and vomiting induced by cisplatin chemotherapy (see Table 5).

a Cisplatin administration began within 10 minutes of granisetron hydrochloride injection infusion and continued for 1.5 to 3.0 hours. Mean cisplatin dose was 86 mg/m2 in the granisetron hydrochloride injection group and 80 mg/m2 in the placebo group.
b No vomiting and no moderate or severe nausea.

Granisetron hydrochloride injection was also evaluated in a randomized dose response study of cancer patients receiving cisplatin ≧75 mg/m2. Additional chemotherapeutic agents included: anthracyclines, carboplatin, cytostatic antibiotics, folic acid derivatives, methylhydrazine, nitrogen mustard analogs, podophyllotoxin derivatives, pyrimidine analogs, and vinca alkaloids. Granisetron hydrochloride injection doses of 10 and 40 mcg/kg were superior to 2 mcg/kg in preventing cisplatin-induced nausea and vomiting, but 40 mcg/kg was not significantly superior to 10 mcg/kg (see Table 6).

a Cisplatin administration began within 10 minutes of granisetron hydrochloride injection infusion and continued for 2.6 hours (mean). Mean cisplatin doses were 96 to 99 mg/m2.
b No vomiting and no moderate or severe nausea.

Granisetron hydrochloride injection was also evaluated in a double-blind, randomized dose response study of 353 patients stratified for high ( ≧80 to 120 mg/m2) or low (50 to 79 mg/m2) cisplatin dose. Response rates of patients for both cisplatin strata are given in Table 7.

a Cisplatin administration began within 10 minutes of granisetron hydrochloride injection infusion and continued for 2 hours (mean). Mean cisplatin doses were 64 and 98 mg/m2 for low and high strata.
b No vomiting and no use of rescue antiemetic.

For both the low and high cisplatin strata, the 10, 20, and 40 mcg/kg doses were more effective than the 5 mcg/kg dose in preventing nausea and vomiting within 24 hours of chemotherapy administration. The 10 mcg/kg dose was at least as effective as the higher doses.

Moderately Emetogenic Chemotherapy Granisetron hydrochloride injection, 40 mcg/kg, was compared with the combination of chlorpromazine (50 to 200 mg/24 hours) and dexamethasone (12 mg) in patients treated with moderately emetogenic chemotherapy, including primarily carboplatin >300 mg/m2, cisplatin 20 to 50 mg/m2 and cyclophosphamide >600 mg/m2. Granisetron hydrochloride injection was superior to the chlorpromazine regimen in preventing nausea and vomiting (see Table 8).

a Patients also received dexamethasone, 12 mg.
b No vomiting and no moderate or severe nausea.

In other studies of moderately emetogenic chemotherapy, no significant difference in efficacy was found between granisetron hydrochloride doses of 40 mcg/kg and 160 mcg/kg.

Repeat-Cycle Chemotherapy

In an uncontrolled trial, 512 cancer patients received granisetron hydrochloride injection, 40 mcg/kg, prophylactically, for two cycles of chemotherapy, 224 patients received it for at least four cycles, and 108 patients received it for at least six cycles. Granisetron hydrochloride injection efficacy remained relatively constant over the first six repeat cycles, with complete response rates (no vomiting and no moderate or severe nausea in 24 hours) of 60% to 69%. No patients were studied for more than 15 cycles.

Pediatric Studies

A randomized double-blind study evaluated the 24-hour response of 80 pediatric cancer patients (age 2 to 16 years) to granisetron hydrochloride injection 10, 20 or 40 mcg/kg. Patients were treated with cisplatin ≧ 60 mg/m2, cytarabine ≧ 3 g/m2, cyclophosphamide ≧ 1 g/m2 or nitrogen mustard ≧ 6 mg/m2 (see Table 9).

a No vomiting and no moderate or severe nausea.

A second pediatric study compared granisetron hydrochloride injection 20 mcg/kg to chlorpromazine plus dexamethasone in 88 patients treated with ifosfamide ≧ 3 g/m2/day for two or three days. Granisetron hydrochloride injection was administered on each day of ifosfamide treatment. At 24 hours, 22% of granisetron hydrochloride injection patients achieved complete response (no vomiting and no moderate or severe nausea in 24 hours) compared with 10% on the chlorpromazine regimen. The median number of vomiting episodes with granisetron hydrochloride injection was 1.5; with chlorpromazine it was 7.