Rifaximin: Price, Dosage & Where to Buy

Rifaximin is a rifamycin antibacterial used to treat travellers' diarrhoea caused by noninvasive strains of Escherichia coli. It is also used in adults to reduce recurrence of overt hepatic encephalopathy and to treat irritable bowel syndrome with diarrhoea; rifaximin requires a prescription in the United Kingdom and is available as oral tablets.

Rifaximin treats travellers' diarrhoea caused by noninvasive strains of Escherichia coli in adults and children aged 12 years and older. It is not intended for travellers' diarrhoea accompanied by fever or blood in the stool, or diarrhoea caused by other pathogens.

In adults, it is also indicated to reduce the risk of overt hepatic encephalopathy recurring and to treat irritable bowel syndrome with diarrhoea. When used for infection, treatment should be limited to infections proven or strongly suspected to involve susceptible bacteria, to help reduce the development of antibiotic resistance.

Rifaximin belongs to the rifamycin group of antibiotics. These medicines interfere with a bacterial enzyme needed to make RNA, which carries the instructions bacteria use to produce proteins. Disrupting this process limits bacterial growth.

Rifaximin acts mainly within the gut, where its antibacterial activity affects susceptible bacteria. Its local action is relevant to its intestinal uses, although more of the medicine can reach the bloodstream in people with severe liver impairment.

The label lists oral tablets in strengths of 200 mg and 550 mg. The label lists 200 mg 3 times a day for 3 days for travellers' diarrhoea. The label lists 550 mg 2 times a day for reducing recurrence of overt hepatic encephalopathy in adults.

The label lists 550 mg 3 times a day for 14 days for irritable bowel syndrome with diarrhoea in adults. The label lists retreatment up to 2 times with the same regimen when irritable bowel syndrome symptoms recur. Administration may be with or without food.

These are indication-specific label regimens, rather than personalised prescribing advice. The appropriate regimen depends on the condition being treated and the prescriber's assessment. Severe liver impairment requires caution because exposure to rifaximin in the bloodstream increases.

Safety and effectiveness have not been established in children below the labelled age groups. Treatment for suspected bacterial infection should reflect bacterial susceptibility information where available.

A missed dose can interrupt the prescribed treatment schedule. Usual pharmacy advice is to resume when remembered unless the next scheduled dose is nearly due, in which case the missed dose is skipped.

A double dose should not be used to compensate. A pharmacist can clarify how to resume the prescribed course.

There are no available data on rifaximin use in pregnant women to assess medicine-associated risks. Animal studies showed developmental malformations, and the label warns of potential harm to the unborn baby. There is no information about rifaximin in human milk, effects on breastfed infants or effects on milk production.

Decisions during breastfeeding should consider its benefits, the mother's clinical need and potential adverse effects on the infant. Discuss pregnancy or breastfeeding with the prescriber.

The label specifies storage at 20°C to 25°C, with temperature excursions permitted to 15°C to 30°C. Keep the tablets in their original packaging and out of the sight and reach of children.