Amitiza Dosage, forms & strengths
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Get started todayAmitiza (lubiprostone) is a chloride channel activator that is used for its laxative effect to treat various forms of constipation. It is manufactured by Takeda Pharmaceuticals. Amitiza is U.S. Food and Drug Administration (FDA) approved in the treatment of chronic idiopathic constipation (CIC) in adults. It is also approved to treat opioid-induced constipation (OIC) in men and women taking opioids for chronic non-cancer pain and to treat irritable bowel syndrome with constipation (IBS-C) in women 18 years of age and older. Amitiza is not approved to treat any condition in pediatric patients.
How does Amitiza work?
Amitiza (lubiprostone) is a fatty acid that activates the CIC-2 chloride channels in your gastrointestinal epithelial cells. Activating these channels increases the release of chloride-rich fluid into your intestines without affecting your serum electrolyte concentrations. Increased fluid secretion helps improve gastrointestinal motility and leads to spontaneous bowel movements (SBM). In clinical studies, this decreased symptoms such as bloating, abdominal discomfort, and straining within 7 days.
Amitiza dosage forms and strengths
Amitiza is available as a gelatin capsule imprinted with “SPI” on one side in the following strengths:
- 8 mcg capsule
- 24 mcg capsule
Amitiza dosage
Amitiza is typically taken twice a day with food and water. Your dose may need to be adjusted if you have moderate hepatic impairment to severe hepatic impairment.
Amitiza adult dosage chart
| Indication | Standard dosage | Dose with moderate liver impairment | Dose with severe hepatic impairment |
|---|---|---|---|
| Chronic idiopathic constipation (CIC) | 24mcg by mouth twice daily with food and water. | 16mcg by mouth twice daily with food and water. | 8mcg by mouth twice daily with food and water. |
| Opioid-induced constipation (OIC) | 24mcg by mouth twice daily with food and water. | 16mcg by mouth twice daily with food and water. | 8mcg by mouth twice daily with food and water. |
| Irritable bowel syndrome with constipation (IBS-C) | 8mcg by mouth twice daily with food and water. | No dose adjustment necessary. | 8mcg by mouth once daily with food and water. |
The safety and efficacy have not been established in clinical trials involving pediatric patients under the age of 18.
Amitiza dosage restrictions
For patients taking Amitiza for CIC and OIC:
- No dose adjustment is necessary with mild hepatic impairment (Child-Pugh Class A).
- With moderate hepatic impairment (Child-Pugh Class B), the recommended dose of Amitiza is 16mcg by mouth twice daily.
- With severe hepatic impairment (Child-Pugh Class C), the recommended dose of Amitiza is 8mcg by mouth twice daily.
For patients taking Amitiza for IBS-C:
- No dose adjustment is needed with mild (Child-Pugh Class A) or moderate (Child-Pugh Class B) hepatic impairment.
- With severe hepatic impairment (Child-Pugh Class C), the recommended dose of Amitiza is 8mcg once daily. If tolerated, the dose can be increased but will need to be monitored very closely.
How to take Amitiza
- Read the Full Prescribing Drug Information including the Black Boxed Warning, Instructions for Use, and Medication Guide that comes with Amitiza.
- Take Amitiza exactly as your doctor prescribes it to you. Do not change your dose or stop taking Amitiza without discussing it with them first.
- Amitiza is typically taken twice daily with food and water. You should swallow the Amitiza capsules whole. Do not break, crush, or chew Amitiza capsules.
- If you miss a dose of Amitiza, take the missed dose immediately. If it is near the time of your next dose, skip the dose you missed and resume your regular schedule. Do not take extra doses to make up for a missed dose.
- Store Amitiza capsules in a tightly closed bottle at room temperature between 15°C-30°C (59°F-86°F). Keep Amitiza away from light and extreme temperatures.
Amitiza dosage FAQs
What are some common side effects of Amitiza?
The most common adverse effects of Amitiza include:
- Nausea
- Diarrhea
- Headache
- Abdominal pain
- Abdominal distension
- Flatulence (gas)
- Vomiting
- Edema
- Loose stools
- Weakness (asthenia)
- Dizziness
- Fatigue
Amitiza can cause serious adverse reactions, including:
- Hypersensitivity reactions including hives, swelling, and difficulty breathing
- Severe diarrhea
- Low blood pressure and fainting (syncope)
- Shortness of breath (dyspnea)
- Chest tightness or pain
Contact your doctor for medical advice about any side effects you experience while taking Amitiza. You can report your side effects to the FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
What are some drug interactions with Amitiza?
When Amitiza is taken with other drugs, it may change the way they work or increase the frequency and severity of side effects. Make sure your doctor is aware of all prescription drugs, over-the-counter medications, vitamins, and herbal supplements you take. Some major drug interactions with Amitiza include:
- Dolophine (methadone) may decrease the effectiveness of Amitiza
Are there any contraindications or precautions with Amitiza?
You should not take Amitiza if you have had an allergic reaction to Amitiza or its inactive ingredients. You should also not take this medication if you have a known blockage in your bowels.
You should notify your doctor if you experience any serious adverse effects such as severe diarrhea, low blood pressure, fainting, or shortness of breath.
How long does Amitiza stay in your system?
Amitiza has a half-life of between 1 to 1.5 hours and will stay in your circulation for approximately 7.5 hours after your last dose.
How long does it take for Amitiza to start working?
Amitiza typically works very quickly. Studies have shown that around 57% of patients had a bowel movement within 24 hours of taking Amitiza and 80% had a bowel movement within 48 hours. This was at a significantly higher rate when compared to placebo.
Can I drink alcohol while taking Amitiza?
There is no known drug interaction between Amitiza and alcohol. Alcohol can increase the risk of certain side effects such as dizziness and nausea.
Will I have withdrawal symptoms or rebound constipation if I stop taking Amitiza?
There was no report of withdrawal symptoms when Amitiza was stopped during clinical studies. Also, after a month of treatment, no rebound constipation occurred after discontinuing Amitiza.
How do I store Amitiza?
Store Amitiza tablets in the original bottle at room temperature between 15°C-30°C (59°F-86°F). Always keep Amitiza and all other medications out of the reach of children.
Is it safe to use Amitiza while pregnant or breastfeeding?
There is very limited data on the safety of taking Amitiza during pregnancy. Animal studies did not show any fetal deformations. There is no available data on whether Amitiza is found in breast milk or the effects it may have on your infant. During animal studies, Amitiza was not found in rat milk. If you are taking Amitiza while breastfeeding, monitor your infant for diarrhea. You should always discuss the risks and benefits of any medication with your healthcare provider if you are pregnant, plan on becoming pregnant, or are breastfeeding.
Is there a generic for Amitiza?
Currently, there is a generic for Amitiza available on the market. However, you will still pay less for brand-name Amitiza through NiceRx if eligible for assistance.
Related resources for Amitiza dosage
- https://reference.medscape.com/drug/Amitiza-lubiprostone-999757
- https://www.Amitizahcp.com/
- https://www.us.astellas.com/docs/Amitiza_WPI.pdf
- https://www.pdr.net/drug-summary/Amitiza-lubiprostone-2544
- https://www.mayoclinic.org/drugs-supplements/lubiprostone-oral-route/description/drg-20075675
- https://www.drugs.com/search.php?searchterm=Amitiza&a=1
