Lubiprostone is a prescription medication, sold under the brand name Amitiza, designed to treat specific types of constipation. The medication works locally in the intestines as a chloride channel activator. By activating these channels in the intestinal lining, it increases the secretion of fluid into the gut. This additional fluid softens the stool, promoting more regular bowel movements and making them easier to pass.
Recommended Dosages by Condition
Chronic Idiopathic Constipation (CIC)
For adults diagnosed with chronic idiopathic constipation, a condition of ongoing constipation without a known cause, the standard recommended dosage is 24 micrograms (mcg) taken twice daily. This dosage is intended to provide a consistent effect in stimulating intestinal fluid to relieve symptoms. Patients should have periodic assessments with their doctor to determine if continued therapy is necessary.
Opioid-Induced Constipation (OIC)
Adults experiencing constipation as a side effect of chronic, non-cancer pain treatment with opioids may also be prescribed lubiprostone. The recommended dosage for this group is 24 mcg taken twice per day. This treatment is for patients who do not require frequent escalations in their opioid dosage. It is important to note that the effectiveness of lubiprostone has not been established for patients taking diphenylheptane opioids like methadone.
Irritable Bowel Syndrome with Constipation (IBS-C)
For women aged 18 and older with irritable bowel syndrome with constipation, the recommended dosage is 8 mcg taken twice daily. This lower dose is a result of clinical studies aiming to balance the medication’s effectiveness and the occurrence of side effects. The 8 mcg dose improves symptoms like abdominal pain and bloating while minimizing adverse effects such as nausea, which can be more pronounced at higher doses.
Administration Guidelines
Proper administration of lubiprostone helps manage its potential side effects. The medication should always be taken orally with both food and water. This practice significantly reduces the incidence and severity of nausea, the most commonly reported side effect.
Lubiprostone is supplied as a soft gelatin capsule and must be swallowed whole. Patients should not crush, break, or chew the capsules. Altering the capsule can affect how the medication is released and absorbed.
To support the medication’s action, maintaining adequate hydration is beneficial. Drinking plenty of fluids, such as six to eight glasses of water daily, can help soften the stool. This works with the drug’s mechanism to promote easier bowel movements.
Dosage Adjustments for Specific Populations
The standard dosage of lubiprostone may need to be modified for those with impaired liver function. Adjustments are based on the severity of the impairment, often classified using the Child-Pugh scale. Patients with mild hepatic impairment typically do not require a dose adjustment.
In cases of moderate liver impairment (Child-Pugh Class B), the starting dose for treating CIC or OIC is reduced to 16 mcg twice daily. For severe liver impairment (Child-Pugh Class C), the dose is further lowered to 8 mcg twice daily for these conditions. For IBS-C, no adjustment is needed for moderate impairment, but for severe impairment, the dose is reduced to 8 mcg once daily. If these lower doses are tolerated but do not provide an adequate response, a doctor may consider escalating the dose with careful monitoring.
Dosage adjustments are not required for patients based on kidney function or for the elderly. While older patients may experience a lower rate of nausea, the standard dosage is used unless other health factors, like liver impairment, are present. All dosage decisions must be made by a healthcare professional.
Managing Missed or Extra Doses
If a dose is missed, the recommended action is to take it as soon as it is remembered. However, if the time is very close to the next scheduled dose, the missed dose should be skipped to avoid taking two doses too close together. Patients should then resume their regular dosing schedule and never take a double dose.
Taking more than the prescribed amount of lubiprostone can lead to an overdose. In the event of a suspected overdose, seek medical help immediately or contact a poison control center at 1-800-222-1222. The symptoms of an overdose are an intensification of the drug’s known side effects, which can include severe nausea, vomiting, diarrhea, dizziness, stomach pain, headache, and feeling faint.