Linaclotide is the first guanylate cyclase-C agonist available in the UK. It may be prescribed to improve symptoms of abdominal pain, bloating and constipation in adults with moderate-to-severe irritable bowel syndrome with constipation (IBS-C).
It improves symptoms of IBS-C by decreasing sensitivity to abdominal pain (visceral sensitivity); it works by increasing the amount of fluid in the intestines and increasing the speed that waste moves through the colon (accelerates transit).
The recommended dose is one capsule (290 micrograms) once daily. The capsule should be taken 30 minutes before a meal.
There is good evidence from large, well-conducted trials to suggest that people experience significant decrease (about 50%) in abdominal pain, bloating (40%) and improved stool frequency (improvement from 1.7 to 5.7 weekly spontaneous bowel movements).
Not all people respond to the treatment but those that do will notice an improvement in symptoms after as little as one week of treatment.
The most common side effect is diarrhoea, which is normally short lived (occurring in about 20% of people). Other less common side effects are: abdominal pain, flatulence, abdominal distension and dizziness.
No. Should prolonged (more than one week) or severe diarrhoea occur, medical advice should be sought and the drug should be stopped. Linaclotide does not appear to interact with other drugs but if diarrhoea develops whilst taking the drug the absorption of the oral contraceptive pill may be affected and other forms of contraception should be used.
Due to the limited amount of data collected, it is preferable to avoid the use of linaclotide during pregnancy and breast-feeding.