Alosetron

Generic Name: alosetron

Over-the-Counter (OTC)

Brand Names:

Alosetron

11 DESCRIPTION The active ingredient in alosetron tablets USP, is alosetron hydrochloride (HCl) USP, a potent and selective antagonist of the serotonin 5-HT 3 receptor type. Chemically, alosetron is designated as 2,3,4,5-tetrahydro-5-methyl-2-[(5-methyl-1H-imidazol-4-yl)methyl]-1H-pyrido[4,3-b]indol-1-one, monohydrochloride. Alosetron is achiral and has the empirical formula C 17 H 18 N 4 O•HCl, representing a molecular weight of 330.8.

Overview

11 DESCRIPTION The active ingredient in alosetron tablets USP, is alosetron hydrochloride (HCl) USP, a potent and selective antagonist of the serotonin 5-HT 3 receptor type. Chemically, alosetron is designated as 2,3,4,5-tetrahydro-5-methyl-2-[(5-methyl-1H-imidazol-4-yl)methyl]-1H-pyrido[4,3-b]indol-1-one, monohydrochloride. Alosetron is achiral and has the empirical formula C 17 H 18 N 4 O•HCl, representing a molecular weight of 330.8.

Uses

1 INDICATIONS AND USAGE Alosetron tablets are indicated only for women with severe diarrhea-predominant irritable bowel syndrome (IBS) who have: chronic IBS symptoms (generally lasting 6 months or longer), had anatomic or biochemical abnormalities of the gastrointestinal tract excluded, and not responded adequately to conventional therapy. Diarrhea-predominant IBS is severe if it includes diarrhea and one or more of the following: frequent and severe abdominal pain/discomfort, frequent bowel urgency or fecal incontinence, disability or restriction of daily activities due to IBS. Because of infrequent but serious gastrointestinal adverse reactions associated with alosetron tablets, the indication is restricted to those patients for whom the benefit-to-risk balance is most favorable.

Dosage

2 DOSAGE AND ADMINISTRATION Starting dose is 0.5 mg twice a day ( 2.1 ) May increase dose to 1 mg twice a day after 4 weeks if starting dosage is well tolerated but does not adequately control IBS symptoms ( 2.1 ) Discontinue alosetron tablets in patients who have not had adequate control of IBS symptoms after 4 weeks of treatment with 1 mg twice a day. ( 2.1 ) 2.1 Adult Patients To lower the risk of constipation, alosetron tablets should be started at a dosage of 0.5 mg twice a day. Patients who become constipated at this dosage should stop taking alosetron tablets until the constipation resolves. They may be restarted at 0.5 mg once a day. If constipation recurs at the lower dose, Alosetron tablets should be discontinued immediately.

Side Effects

6 ADVERSE REACTIONS The following adverse reactions are described in more detail in other sections of the label: Complications of constipation [see Boxed Warning , Warnings and Precautions ( 5.1 )] Ischemic colitis [see Boxed Warning , Warnings and Precautions ( 5.2 )] Most common adverse reactions (incidence >2% and >placebo) in clinical studies were constipation, abdominal discomfort and pain, nausea and gastrointestinal discomfort and pain. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Lifestar Pharma LLC at 1-888-995-4337 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

Interactions

7 DRUG INTERACTIONS In vivo data suggest that alosetron is primarily metabolized by cytochrome P450 (CYP) 1A2, with minor contributions from CYP3A4 and CYP2C9. Therefore, inducers or inhibitors of these enzymes may change the clearance of alosetron. CYP1A2 inhibitors: Avoid concomitant uses because of increased exposure and half-life of alosetron. Use with fluvoxamine is contraindicated. ( 4.3 , 7.1) CYP3A4 inhibitors: Use with caution in combination due to increased exposure of alosetron. ( 7.2 ) 7.1 CYP1A2 Inhibitors Fluvoxamine is a known strong inhibitor of CYP1A2 and also inhibits CYP3A4, CYP2C9, and CYP2C19.

Warnings

WARNING: SERIOUS GASTROINTESTINAL ADVERSE REACTIONS Infrequent but serious gastrointestinal adverse reactions have been reported with the use of alosetron tablets. These events, including ischemic colitis and serious complications of constipation, have resulted in hospitalization, and rarely, blood transfusion, surgery, and death. 5 WARNINGS AND PRECAUTIONS Serious Complications of Constipation: May occur in some patients without warning. Includes obstruction, ileus, impaction, toxic megacolon, and secondary bowel ischemia and in rare cases perforation and death have been reported. Risk is increased in patients who are elderly, debilitated, or taking medications that decrease bowel motility. ( 5.1 ) Discontinue alosetron tablets immediately if constipation occurs. ( 5.1 ) Ischemic colitis: May occur in some patients without warning. Promptly evaluate patients with signs of ischemic colitis (e.g., rectal bleeding, bloody diarrhea, new or worsening abdominal pain). 4 CONTRAINDICATIONS Do not initiate in patients with constipation ( 4.1 ) History of chronic or severe constipation or sequelae from constipation; intestinal obstruction, stricture, toxic megacolon, gastrointestinal perforation, and/or adhesions; ischemic colitis; impaired intestinal circulation, thrombophlebitis, or hypercoagulable state; Crohn's disease or ulcerative colitis; diverticulitis; sev...

Pregnancy

8.1 Pregnancy Risk Summary The available data with alosetron tablets use in pregnant women are insufficient to draw conclusions about any drug-associated risks for major birth defects, miscarriage, or adverse maternal or fetal outcomes. In animal reproduction studies, no adverse developmental effects were observed with oral administration of alosetron in rats and rabbits during organogenesis at doses 160 to 240 times, respectively, the recommended human dosage (see Data). The estimated background risk of major birth defects and miscarriage for the indicated populations is unknown.

Storage

16 HOW SUPPLIED/STORAGE AND HANDLING Alosetron Tablets USP, 0.5 mg (0.562 mg alosetron HCl equivalent to 0.5 mg alosetron), are round, film coated, white colored biconvex tablets debossed with "LS 702" on one side and plain on other side. Bottles of 30 (NDC 70756-702-30) with child-resistant closures.

Frequently Asked Questions

What is Alosetron used for?

1 INDICATIONS AND USAGE Alosetron tablets are indicated only for women with severe diarrhea-predominant irritable bowel syndrome (IBS) who have: chronic IBS symptoms (generally lasting 6 months or longer), had anatomic or biochemical abnormalities of the gastrointestinal tract excluded, and not responded adequately to conventional therapy. Diarrhea-predominant IBS is severe if it includes diarrhea and one or more of the following: frequent and severe abdominal pain/discomfort, frequent bowel urgency or fecal incontinence, disability or restriction of daily activities due to IBS. Because of infrequent but serious gastrointestinal adverse reactions associated with alosetron tablets, the indication is restricted to those patients for whom the benefit-to-risk balance is most favorable.

What are the side effects of Alosetron?

6 ADVERSE REACTIONS The following adverse reactions are described in more detail in other sections of the label: Complications of constipation [see Boxed Warning , Warnings and Precautions ( 5.1 )] Ischemic colitis [see Boxed Warning , Warnings and Precautions ( 5.2 )] Most common adverse reactions (incidence >2% and >placebo) in clinical studies were constipation, abdominal discomfort and pain, nausea and gastrointestinal discomfort and pain. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Lifestar Pharma LLC at 1-888-995-4337 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

Can I take Alosetron during pregnancy?

8.1 Pregnancy Risk Summary The available data with alosetron tablets use in pregnant women are insufficient to draw conclusions about any drug-associated risks for major birth defects, miscarriage, or adverse maternal or fetal outcomes. In animal reproduction studies, no adverse developmental effects were observed with oral administration of alosetron in rats and rabbits during organogenesis at doses 160 to 240 times, respectively, the recommended human dosage (see Data). The estimated background risk of major birth defects and miscarriage for the indicated populations is unknown.

What are the important warnings for Alosetron?

WARNING: SERIOUS GASTROINTESTINAL ADVERSE REACTIONS Infrequent but serious gastrointestinal adverse reactions have been reported with the use of alosetron tablets. These events, including ischemic colitis and serious complications of constipation, have resulted in hospitalization, and rarely, blood transfusion, surgery, and death. 5 WARNINGS AND PRECAUTIONS Serious Complications of Constipation: May occur in some patients without warning. Includes obstruction, ileus, impaction, toxic megacolon, and secondary bowel ischemia and in rare cases perforation and death have been reported. Risk is increased in patients who are elderly, debilitated, or taking medications that decrease bowel motility. ( 5.1 ) Discontinue alosetron tablets immediately if constipation occurs. ( 5.1 ) Ischemic colitis: May occur in some patients without warning. Promptly evaluate patients with signs of ischemic colitis (e.g., rectal bleeding, bloody diarrhea, new or worsening abdominal pain). 4 CONTRAINDICATIONS Do not initiate in patients with constipation ( 4.1 ) History of chronic or severe constipation or sequelae from constipation; intestinal obstruction, stricture, toxic megacolon, gastrointestinal perforation, and/or adhesions; ischemic colitis; impaired intestinal circulation, thrombophlebitis, or hypercoagulable state; Crohn's disease or ulcerative colitis; diverticulitis; sev...

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Medical Disclaimer

This drug information is for educational purposes only and should not replace professional medical advice. Drug information is sourced from the FDA National Drug Code Directory and Structured Product Labeling. Always consult with a healthcare provider before starting, stopping, or changing any medication.