Medical Editor: John P. Cunha, DO, FACOEP
Alosetron Hydrochloride Tablets are a selective serotonin 5-HT3 antagonist 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. Alosetron hydrochloride is available in generic form. Common side effects of alosetron hydrochloride include:
- abdominal discomfort and pain,
- gastrointestinal discomfort and pain,
- abdominal distention,
- vomiting and reflux,
- diarrhea, and
The starting dose of alosetron hydrochloride is 0.5 mg twice a day. The dose of alosetron hydrochloride may be increased to 1 mg twice a day after 4 weeks if starting dosage is well tolerated but does not adequately control IBS symptoms. Alosetron hydrochloride may interact with fluvoxamine, quinolone antibiotics, cimetidine, ketoconazole, clarithromycin, telithromycin, protease inhibitors, voriconazole, and itraconazole. Tell your doctor all medications and supplements you use. Tell your doctor if you are pregnant or plan to become pregnant before using alosetron hydrochloride; it is not expected to be harmful to a fetus. It is unknown if alosetron hydrochloride passes into breast milk. Consult your doctor before breastfeeding.
Our Alosetron Hydrochloride Tablets Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
The following adverse reactions are described in more detail in other sections of the label:
- Complications of constipation [see BOXED WARNING, WARNINGS AND PRECAUTIONS]
- Ischemic colitis [see BOXED WARNING, WARNINGS AND PRECAUTIONS]
Clinical Trials Experience
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.
Patients With Irritable Bowel Syndrome
Table 1 summarizes adverse reactions from 22 repeat-dose studies in patients with IBS who were treated with 1 mg of alosetron hydrochloride tablets twice daily for 8 to 24 weeks. The adverse reactions in Table 1 were reported in 1% or more of patients who received alosetron hydrochloride tablets and occurred more frequently on alosetron hydrochloride tablets than on placebo. A statistically significant difference was observed for constipation in patients treated with alosetron hydrochloride tablets compared to placebo (p < 0.0001).
Table 1: Adverse Reactions Reported in ≥ 1% of
Patients With Irritable Bowel Syndrome and More Frequently on Alosetron
Hydrochloride Tablets 1 mg Twice Daily Than Placebo
(n = 2,363)
|Alosetron HCl 1 mg twice daily
(n = 8,328)
|Abdominal discomfort and pain||4%||7%|
|Gastrointestinal discomfort and pain||3%||5%|
|Regurgitation and reflux||2%||2%|
Constipation is a frequent and dose-related side effect of treatment with alosetron hydrochloride tablets [see WARNINGS AND PRECAUTIONS]. In clinical studies constipation was reported in approximately 29% of patients with IBS treated with alosetron hydrochloride tablets 1 mg twice daily (n = 9,316). This effect was statistically significant compared to placebo (p < 0.0001). Eleven percent (11%) of patients treated with alosetron hydrochloride tablets 1 mg twice daily withdrew from the studies due to constipation. Although the number of patients with IBS treated with alosetron hydrochloride tablets 0.5 mg twice daily is relatively small (n = 243), only 11% of those patients reported constipation and 4% withdrew from clinical studies due to constipation. Among the patients treated with alosetron hydrochloride tablets 1 mg twice daily who reported constipation, 75% reported a single episode and most reports of constipation (70%) occurred during the first month of treatment, with the median time to first report of constipation onset of 8 days. Occurrences of constipation in clinical trials were generally mild to moderate in intensity, transient in nature, and resolved either spontaneously with continued treatment or with an interruption of treatment. However, serious complications of constipation have been reported in clinical studies and in postmarketing experience [see BOXED WARNING and WARNINGS AND PRECAUTIONS]. In Studies 1 and 2, 9% of patients treated with alosetron hydrochloride tablets reported constipation and 4 consecutive days with no bowel movement [see Clinical Studies]. Following interruption of treatment, 78% of the affected patients resumed bowel movements within a 2-day period and were able to re-initiate treatment with alosetron hydrochloride tablets.
A similar incidence in elevation of ALT ( > 2-fold) was seen in patients receiving alosetron hydrochloride tablets or placebo (1% vs. 1.2%). A single case of hepatitis (elevated ALT, AST, alkaline phosphatase, and bilirubin) without jaundice in a patient receiving alosetron hydrochloride tablets was reported in a 12-week study. A causal association with alosetron hydrochloride tablets has not been established.
Patient experience in controlled clinical trials is insufficient to estimate the incidence of ischemic colitis in patients taking alosetron hydrochloride tablets for longer than 6 months.
Women With Severe Diarrhea-Predominant Irritable Bowel Syndrome
Table 2 summarizes the gastrointestinal adverse reactions from 1 repeat-dose study in female patients with severe diarrheapredominant IBS who were treated for 12 weeks. The adverse reactions in Table 2 were reported in 3% or more of patients who received alosetron hydrochloride tablets and occurred more frequently with alosetron hydrochloride tablets than with placebo. Other events reported in 3% or more of patients who received alosetron hydrochloride tablets and occurring more frequently with alosetron hydrochloride tablets than with placebo included upper respiratory tract infection, viral gastroenteritis, muscle spasms, headaches, and fatigue.
Table 2: Gastrointestinal Adverse Reactions Reported
in ≥ 3% of Women With Severe Diarrhea- Predominant Irritable Bowel
Syndrome and More Frequently on Alosetron Hydrochloride Tablets Than Placebo.
(n = 176)
|Alosetron 0.5 mg once daily
(n = 175)
|Alosetron 1 mg once daily
(n = 172)
|Alosetron 1 mg twice daily
|Abdominal pain upper||1%||3%||1%||1%|
Adverse reactions reported in another study of 701 women with severe diarrhea-predominant IBS were similar to those shown in Table 2. Gastrointestinal adverse reactions reported in 3% or more of patients who received alosetron hydrochloride tablets and occurring more frequently with alosetron hydrochloride tablets than with placebo included constipation (14% and 10% of patients taking alosetron hydrochloride tablets 1 mg twice daily or 0.5 mg as needed, respectively, compared with 2% taking placebo), abdominal pain, nausea, vomiting, and flatulence. Other events reported in 3% or more of patients who received alosetron hydrochloride tablets and occurring more frequently with alosetron hydrochloride tablets than with placebo included nasopharyngitis, sinusitis, upper respiratory tract infection, urinary tract infection, viral gastroenteritis, and cough.
Constipation: Constipation was the most frequent adverse reaction among women with severe diarrheapredominant IBS represented in Table 2. There was a dose response in the groups treated with alosetron hydrochloride tablets in the number of patients withdrawn due to constipation (2% on placebo, 5% on 0.5 mg once daily, 8% on 1 mg once daily, and 11% on 1 mg twice daily). Among these patients with severe diarrhea-predominant IBS treated with alosetron hydrochloride tablets who reported constipation most (75%) reported one episode which occurred within the first 15 days of treatment and persisted for 4 to 5 days.
Other Events Observed During Clinical Evaluation Of Alosetron Hydrochloride Tablets
During its assessment in clinical trials, multiple and single doses of alosetron hydrochloride tablets were administered, resulting in 11,874 subject exposures in 86 completed clinical studies. The conditions, dosages, and duration of exposure to alosetron hydrochloride tablets varied between trials, and the studies included healthy male and female volunteers as well as male and female patients with IBS and other indications.
In the listing that follows, reported adverse reactions were classified using a standardized coding dictionary. Only those events that an investigator believed were possibly related to alosetron hydrochloride tablets, occurred in at least 2 patients, and occurred at a greater frequency during treatment with alosetron hydrochloride tablets than during placebo administration are presented. Serious adverse reactions occurring in at least 1 patient for whom an investigator believed there was reasonable possibility that the event was related to treatment with alosetron hydrochloride tablets and occurring at a greater frequency in patients treated with alosetron hydrochloride tablets than placebo-treated patients are also presented.
In the following listing, events are categorized by body system. Within each body system, events are presented in descending order of frequency. The following definitions are used: infrequent adverse reactions are those occurring on one or more occasion in 1/100 to 1/1,000 patients; rare adverse reactions are those occurring on one or more occasion in fewer than 1/1,000 patients. Although the events reported occurred during treatment with alosetron hydrochloride tablets, they were not necessarily caused by it.
Cardiovascular: Infrequent: Tachyarrhythmias. Rare: Arrhythmias, increased blood pressure, and extrasystoles.
Drug Interaction, Overdose, and Trauma: Rare: Contusions and hematomas.
Ear, Nose, and Throat: Rare: Ear, nose, and throat infections; viral ear, nose, and throat infections; and laryngitis.
Eye: Rare: Light sensitivity of eyes.
Gastrointestinal: Infrequent: Hyposalivation, dyspeptic symptoms, gastrointestinal spasms, ischemic colitis [see WARNINGS AND PRECAUTIONS], and gastrointestinal lesions. Rare: Abnormal tenderness, colitis, gastrointestinal signs and symptoms, proctitis, diverticulitis, positive fecal occult blood, hyperacidity, decreased gastrointestinal motility and ileus, gastrointestinal obstructions, oral symptoms, gastrointestinal intussusception, gastritis, gastroduodenitis, gastroenteritis, and ulcerative colitis.
Hepatobiliary Tract and Pancreas: Rare: Abnormal bilirubin levels and cholecystitis.
Lower Respiratory: Infrequent: Breathing disorders.
Musculoskeletal: Rare: Muscle pain; muscle stiffness, tightness and rigidity; and bone and skeletal pain.
Neurological: Infrequent: Hypnagogic effects. Rare: Memory effects, tremors, dreams, cognitive function disorders, disturbances of sense of taste, disorders of equilibrium, confusion, sedation, and hypoesthesia.
Non-Site Specific: Infrequent: Malaise and fatigue, cramps, pain, temperature regulation disturbances. Rare: Burning sensations, hot and cold sensations, cold sensations, and fungal infections.
Psychiatry: Infrequent: Anxiety. Rare: Depressive moods.
Reproduction: Rare: Sexual function disorders, female reproductive tract bleeding and hemorrhage, reproductive infections, and fungal reproductive infections.
Skin: Infrequent: Sweating and urticaria. Rare: Hair loss and alopecia; acne and folliculitis; disorders of sweat and sebum; allergic skin reaction; eczema; skin infections; dermatitis and dermatosis; and nail disorders.
In addition to events reported in clinical trials, the following events have been identified during use of alosetron hydrochloride tablets in clinical practice. Because they were reported voluntarily from a population of unknown size, estimates of frequency cannot be made. These events have been chosen for inclusion due to a combination of their seriousness, frequency of reporting, or potential causal connection to alosetron hydrochloride tablets.
Read the entire FDA prescribing information for Alosetron Hydrochloride (alosetron hydrochloride)
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