5-HT₃ Receptor ( IC50 = 17 μM )

Granisetron significantly reduces the risk of cisplatin-induced emesis in piglets; certain animals are fully protected against both the acute and delayed phases of the condition.[2] When given three times a day, granisetron (1 mg/kg, i.m.) dramatically lessens the vomiting and retching that cats experience on days 1 and 2 as a result of cisplatin by 100% and 75%, respectively.[3] In rats, granisetron or dexamethasone significantly reduces colonic levels of malondialdehyde and inflammatory cytokines, inhibits myeloperoxidase activity, and improves macroscopic and histologic scores.[4] Granisetron, not only prevents cholera toxin-induced jejunal net fluid secretion but also, and in proportion, inhibits 5-HT release into the intestinal lumen of mice.[5]

The activity of BRL 43694 (granisetron) was investigated using established models of 5-HT3 receptor activity. In guinea-pig isolated ileum, BRL 43694 antagonised the contractions evoked by relatively high concentrations of 5-HT (pA2 = 8.1 +/- 0.2). However, except in high concentrations, BRL 43694 did not affect the contractions of similar preparations of ileum, evoked by electrical field stimulation (cholinergically mediated), the nicotinic agonist dimethylphenyl piperazinium (DMPP) or by cholecystokinin octapeptide. Similarly, BRL 43694 did not affect electrically evoked, cholinergically mediated contractions of rat or human isolated stomach. In other models of 5-HT3 receptor activity (rabbit isolated heart, Bezold-Jarisch reflex in anaesthetised rats), potent antagonism by BRL 43694 was demonstrated. In radioligand binding studies on rat brain membranes, BRL 43694 had little or no affinity for 5-HT1A, 5-HT1B, 5-HT2 or for many other binding sites. BRL 43694 may therefore be a potent and selective 5-HT3 receptor antagonist[Eur J Pharmacol. 1989 Jan 10;159(2):113-24.].

In rat forestomach GR reduced 5-HT-evoked contractions at IC50 17 /- 6 uM. GR 0.003-0.03 nM dose-dependently decreased s-HT tachycardia in the isolated rabbit heart; at high concentrations, GR decreased both submaximal and maximal responses to 5-HT.

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1. In this study, researchers investigated the effects of two 5-HT3 antagonists, ondansetron and granisetron, on the action potential duration (APD) and the delayed rectifier current (IK) of feline isolated ventricular myocytes. Whole-cell current and action potential recordings were performed at 37 degrees C with the patch clamp technique. 2. Ondansetron and granisetron blocked IK with a KD of 1.7 +/- 1.0 and 4.3 +/- 1.7 microM, respectively. At a higher concentration (30 microM), both drugs blocked the inward rectifier (IKl). 3. The block of IK was dependent on channel activation. Both drugs slowed the decay of IK tail currents and produced a crossover with the pre-drug current trace. These results are consistent with block and unblock from the open state of the channel. 4. Granisetron showed an intrinsic voltage-dependence as the block increased with depolarization. The equivalent voltage-dependency of block (delta) was 0.10 +/- 0.04, suggesting that granisetron blocks from the intracellular side at a binding site located 10% across the transmembrane electrical field. 5. Ondansetron (1 microM) and granisetron (3 microM) prolonged APD by about 30% at 0.5 Hz. The prolongation of APD by ondansetron was abolished at faster frequencies (3 Hz) showing reverse rate dependence. 6. In conclusion, the 5-HT3 antagonists, ondansetron and granisetron, are open state blockers of the ventricular delayed rectifier and show a clear class III action.

We analyzed the effects of the 5-HT3 receptor antagonist granisetron on both acute and delayed phases of cisplatin-induced emesis in the conscious piglet. Animals that received a high dose of cisplatin (5.5 mg/kg i.v.) were observed continuously for 60 h. Seventeen piglets were treated with cisplatin only and acted as controls. In experimental animals, granisetron (administered before cisplatin) was administered either as a single initial injection (7 mg/kg), alone or in combination with dexamethasone (40 mg), or as multiple injections (1 mg/kg) given every 5 h during the first 30 h of the experiment (cumulative dose: 7 mg/kg). Two other groups of piglets were treated with dexamethasone (40 mg) alone or with multiple injections of ondansetron (7 injections at 3.5 mg/kg), respectively. The latency to the first emetic episode was significantly increased in all groups that received a 5-HT3 receptor antagonist, whatever the agent and the protocol of administration. Piglets treated solely with dexamethasone exhibited a latency similar to that of controls. The total number of emetic events during the 60 h was significantly reduced only in the group of piglets treated repeatedly with granisetron and in the group that received an initial dose (7 mg/kg) of granisetron in combination with dexamethasone. We observed that 3 out of 8 piglets treated repeatedly with granisetron did not vomit throughout the experiment. These results demonstrate that granisetron, when administered repeatedly, is efficacious against delayed emesis. They also suggest that serotonin may be involved in the production of the delayed phase of cisplatin-induced emesis.[2]

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The emetic action of cisplatin was investigated in the cat using a closed circuit video recording system. In initial investigations, cisplatin 3 and 5 mg/kg, i.v. induced emesis over a 2-day period following a latency of 17.6+/-9.6 and 15.6+/-7.8 h, respectively. The anti-emetic efficacy of granisetron and dexamethasone was investigated in the cisplatin 5 mg/kg, i.v.-induced emesis model. In these experiments, cisplatin induced 47.0+/-14.0 and 20.0+/-9.0 retches+vomits on days 1 and 2, respectively, following a latency of 2.4+/-0.4 h. Granisetron (1 mg/kg, i.m.) administered three times per day reduced significantly the retching+vomiting response induced by cisplatin on days 1 and 2 by 100.0% (P<0.05) and 75.0% (P<0.05), respectively; dexamethasone (0.01-1 mg/kg, i.m.) administered three times per day reduced significantly the retching+vomiting response by 68.8-100.0% (P<0.05) and 33.3-100.0% (P<0.05) on days 1 and 2, respectively. The emetic action of cisplatin 7.5 mg/kg, i.v. was also investigated. This dose of cisplatin-induced emesis following a latency of 1.2+/-0.2 h and comprised 119.0+/-20.8 retches+vomits over a 24-h period. Granisetron and dexamethasone antagonized the emesis occurring in the first 3-h period (P<0.05) but were less effective to antagonize the subsequent emetic response (P0.05). The pharmacological sensitivity of low dose cisplatin-induced emesis in the cat is variable but unique and not representative of the clinical situation.[3]

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Inflammatory bowel disease (IBD) is a chronically relapsing inflammation of the gastrointestinal tract, of which the definite etiology remains ambiguous. Considering the adverse effects and incomplete efficacy of currently administered drugs, it is indispensable to explore new candidates with more desirable therapeutic profiles. 5-HT( 3) receptor antagonists have shown analgesic and anti-inflammatory properties in vitro and in vivo. This study aims to investigate granisetron, a 5-HT( 3) receptor antagonist, in acetic acid-induced rat colitis and probable involvement of 5-HT(3) receptors. Colitis was rendered by instillation of 1 mL of 4% acetic acid (vol/vol) and after 1 hour, granisetron (2 mg/kg), dexamethasone (1 mg/kg), meta-chlorophenylbiguanide (mCPBG, 5 mg/kg), a 5-HT( 3) receptor agonist, or granisetron + mCPBG was given intraperitoneally. Twenty-four hours following colitis induction, animals were sacrificed and distal colons were assessed macroscopically, histologically and biochemically (malondialdehyde, myeloperoxidase, tumor necrosis factor-alpha, interleukin-1 beta and interleukin-6). Granisetron or dexamethasone significantly (p < .05) improved macroscopic and histologic scores, curtailed myeloperoxidase activity and diminished colonic levels of inflammatory cytokines and malondialdehyde. The protective effects of granisetron were reversed by concurrent administration of mCPBG. Our data suggests that the salutary effects of granisetron in acetic acid colitis could be mediated by 5-HT(3) receptors.[4]

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1 mg/kg, i.m.

Piglet

Absorption, Distribution and Excretion
Absorption
Absorption of is rapid and complete, though oral bioavailability is reduced to about 60% as a result of first pass metabolism.

Route of Elimination
The remainder of the dose is excreted as metabolites, 48% in the urine and 38% in the feces.

Clearance
0.52 L/h/kg [Cancer Patients with 1 mg bid for 7 days]
0.41 L/h/kg [Healthy subject with a single 1 mg dose]

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Metabolism / Metabolites
Primarily hepatic; undergoes N -demethylation and aromatic ring oxidation followed by conjugation. Animal studies suggest that some of the metabolites may have 5-HT 3 receptor antagonist activity.
Granisetron has known human metabolites that include 9'-Desmethylgranisetron and 7-Hydroxygranisetron.

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Biological Half-Life
4-6 hours in healthy patients, 9-12 hours in cancer patients

Effects During Pregnancy and Lactation
◉ Summary of Use during Lactation
No information is available on the use of granisetron during breastfeeding. Until more data become available, granisetron should be used with caution during breastfeeding. An alternate drug may be preferred.
◉ Effects in Breastfed Infants
Relevant published information was not found as of the revision date.
◉ Effects on Lactation and Breastmilk
A woman nursing an 8-month-old infant 6 to 8 times daily was admitted to the hospital for an appendectomy. During the procedure she received granisetron, cefazolin, ketorolac, rocuronium, succinylcholine, and sufentanil. The patient also received 2 boluses of intravenous propofol of 150 mg followed shortly thereafter by a 50 mg dose. Postoperatively, she was receiving acetaminophen, cefazolin, ibuprofen, and pantoprazole, as well as oxycodone and dimenhydrinate as needed. Twenty-two hours after the procedure, the mother extracted milk for the first time and noted it to be light green in color. Analysis of the green milk using a nonvalidated assay detected no propofol. The green color faded and was absent by postoperative day 4 when she resumed breastfeeding. The authors judged that the green color was possibly caused by propofol or one of its metabolites.

[1]. Br J Pharmacol . 1994 Oct;113(2):527-35.

[2]. J Pharmacol Exp Ther . 1996 Oct;279(1):255-61.

[3]. Eur J Pharmacol . 2000 Mar 10;391(1-2):145-50.

[4]. Hum Exp Toxicol . 2010 Apr;29(4):321-8.

[5]. Br J Pharmacol . 2000 Jul;130(5):1031-6.

Granisetron hydrochloride is an aromatic amide and a member of indazoles.
A serotonin receptor (5HT-3 selective) antagonist that has been used as an antiemetic for cancer chemotherapy patients.
See also: Granisetron Hydrochloride (annotation moved to).

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Drug Indication
Prevention of nausea and vomiting in patients receiving moderately or highly emetogenic chemotherapy, with or without cisplatin, for up to five consecutive days. Sancuso may be used in patients receiving their first chemotherapy regimen or in patients who have previously received chemotherapy.

C18H25CLN4O

348.87

348.171

C, 61.97; H, 7.22; Cl, 10.16; N, 16.06; O, 4.59

107007-99-8

Granisetron; 109889-09-0; 107007-99-8 (HCl)

6918003

White solid powder

1.33g/cm3

532ºC at 760mmHg

290-292°C

275.6ºC

0mmHg at 25°C

1.69

3.449

2

3

2

24

442

2

Cl[H].O=C(C1C2=C([H])C([H])=C([H])C([H])=C2N(C([H])([H])[H])N=1)N([H])C1([H])C([H])([H])[C@@]2([H])C([H])([H])C([H])([H])C([H])([H])[C@@]([H])(C1([H])[H])N2C([H])([H])[H]

QYZRTBKYBJRGJB-UHFFFAOYSA-N

InChI=1S/C18H24N4O.ClH/c1-21-13-6-5-7-14(21)11-12(10-13)19-18(23)17-15-8-3-4-9-16(15)22(2)20-17;/h3-4,8-9,12-14H,5-7,10-11H2,1-2H3,(H,19,23);1H

1-methyl-N-(9-methyl-9-azabicyclo[3.3.1]nonan-3-yl)indazole-3-carboxamide;hydrochloride

BRL43694; BRL 43694; BRL43694A; BRL 43694A; BRL-43694; BRL-43694A; Granisetron Hydrochloride; Granisetron hydrocholride,(S); 1-methyl-N-((1R,3r,5S)-9-methyl-9-azabicyclo[3.3.1]nonan-3-yl)-1H-indazole-3-carboxamide hydrochloride; Granisetron HCl; GRAN; US trade name: Kytril

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: Please store this product in a sealed and protected environment, avoid exposure to moisture.

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Solubility in Formulation 1: ≥ 0.77 mg/mL (2.21 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 7.7 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 0.77 mg/mL (2.21 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 7.7 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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Solubility in Formulation 3: 100 mg/mL (286.64 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with ultrasonication.

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 (Please use freshly prepared in vivo formulations for optimal results.)