Indications
Ramosetron Hydrochloride is used to treat irritable bowel syndrome with diarrhoea (IBS-D), a long-term gut condition causing tummy pain, urgency and loose stools. It is also used to prevent nausea and vomiting caused by cancer chemotherapy.
How It Works
Ramosetron blocks 5-HT3 receptors, which respond to the chemical serotonin. In the gut, too much serotonin signalling speeds up bowel movements and makes the gut more sensitive to pain. Blocking these receptors slows bowel movement, reduces urgency and loose stools, and lowers abdominal pain. In chemotherapy, blocking the same receptors in the gut and brain reduces nausea and vomiting.
Dosage and Administration
Take exactly as prescribed. For IBS with diarrhoea, the usual dose is very small, measured in micrograms: commonly 5 micrograms once a day for men and 2.5 micrograms once a day for women, adjusted by the doctor. Tablets and orally disintegrating tablets are taken once daily; orally disintegrating tablets dissolve on the tongue. For prevention of chemotherapy sickness, the tablet or injection is given before chemotherapy as prescribed; injections are given by a doctor or nurse.
Interactions
- Fluvoxamine can raise Ramosetron levels and increase side effects.
- Other medicines that cause constipation, such as Loperamide, opioid painkillers and anticholinergic drugs, increase the risk of severe constipation.
- Medicines that raise serotonin (such as SSRIs, SNRIs or Tramadol) may rarely cause serotonin syndrome when combined with 5-HT3 blockers.
- Medicines that affect heart rhythm (QT interval) should be used with caution.
Contraindications
- Allergy to Ramosetron or other 5-HT3 blockers.
- History of ischaemic colitis (reduced blood flow to the bowel).
- Constipation, bowel obstruction or toxic megacolon.
- IBS with constipation or mixed IBS.
Side Effects
Common side effects include constipation, hard stools, bloating, stomach discomfort and headache.
Less common but serious effects include severe constipation and ischaemic colitis, which can cause sudden tummy pain and bloody stools. Rarely, liver enzyme changes or allergic reactions occur.
Stop taking it and get urgent medical help if you have sudden or severe abdominal pain, blood in the stool or rectal bleeding, no bowel movement for several days with a swollen belly, or a severe rash or swelling of the face and throat.
Pregnancy and Lactation
There is little information on use in pregnancy. Use it only if your doctor decides it is needed. It is not known whether it passes into breast milk; avoid breastfeeding while taking it unless your doctor advises otherwise.
Precautions and Warnings
Your doctor should rule out other bowel diseases before starting treatment for IBS. Women and older people may be more sensitive and usually start at a lower dose. Tell your doctor about any history of constipation, bowel surgery, liver disease or heart rhythm problems. Stop and seek advice if constipation or hard stools develop.
Overdose
Overdose may cause severe constipation and other increased side effects. Contact a doctor or poison centre; treatment is supportive.
Therapeutic Class
Serotonin 5-HT3 receptor antagonist; antidiarrhoeal for IBS-D and antiemetic.
Storage
Store below 30°C in a dry place, away from light and moisture, and out of the reach of children.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.