Antimotility + antiflatulent Pregnancy: §4.6: there are no adequate and well-controlled studies in pregnant or breastfeeding women for the combination. There are no indications that loperamide or simeticone possesses teratogenic or embryotoxic properties, but as with other medicines it should not be given during pregnancy, especially during the first trimester, unless clinically justified. Simeticone is physiologically inactive, not absorbed from the gastrointestinal tract and not excreted in breast milk. Small amounts of loperamide may appear in human breast milk, so the product is not recommended during breast-feeding. Effect on human fertility has not been evaluated.

Loperamide with simeticone

Brand names: Imodium Plus

This is a fixed-dose combination of the antimotility agent loperamide and the antifoaming agent simeticone, used for acute diarrhoea accompanied by painful gas-related abdominal symptoms such as bloating and cramping.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: Two tablets initially, followed by one tablet after every loose stool

Route: Oral - swallow the tablets whole with a drink of water

Frequency: Initial dose, then one tablet after each loose stool

Max: Not more than 4 tablets should be taken in a day, limited to no more than 2 days

eMC §4.2 (Imodium Dual Action Relief Tablets (GSL), UK SPC). Stated dose is for adults over 18 years. ELDERLY: no dosage adjustments are required. HEPATIC IMPAIRMENT: although no pharmacokinetic data are available in hepatic insufficiency, use with caution because of reduced first pass metabolism (§4.2, §4.4); §4.4 adds that it may result in a relative overdose leading to CNS toxicity and should be used under medical supervision in severe hepatic dysfunction. PAEDIATRIC (source wording, non-per-kg): contraindicated in children under 12 years; adolescents between 12 and 18 years - one tablet initially, followed by one tablet after every loose stool, not more than 4 tablets in a day and limited to no more than 2 days. Verify any under-18 use against a children's formulary. §4.4: if clinical improvement is not observed within 48 hours, administration must be discontinued and the patient advised to consult their physician; patients with AIDS should stop therapy at the earliest signs of abdominal distension; caution is needed in patients with a history of drug abuse (abuse and misuse of loperamide has been described); cardiac events including QT interval and QRS complex prolongation and torsades de pointes have been reported in association with overdose, some fatal, and overdose can unmask existing Brugada syndrome - patients should not exceed the recommended dose or duration. Per-tablet strengths of loperamide hydrochloride and simeticone were not stated in the fetched sections - clinician to confirm from the full SPC.

Dose adjustments

Renal

§4.2: no dosage adjustment is necessary in patients with renal impairment. §4.4 nonetheless advises caution in patients with renal or hepatic impairment because of the risk of accumulation and toxicity (metabolic acidosis).

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Children less than 12 years of age (§4.3)
Hypersensitivity to the active substances or to any of the excipients (§4.3)
Acute dysentery, characterised by blood in stool and high fever (§4.3)
Acute ulcerative colitis; pseudomembranous colitis associated with broad spectrum antibiotics (§4.3)
Bacterial enterocolitis caused by invasive organisms including Salmonella, Shigella and Campylobacter (§4.3)
Must not be used when inhibition of peristalsis is to be avoided due to the possible risk of significant sequelae including ileus, megacolon and toxic megacolon; discontinue promptly if constipation, ileus or abdominal distension develop (§4.3)

Side effects

Dysgeusia (2.6% in loperamide-simeticone clinical trials) and nausea (1.6%) - the most commonly reported ADRs for the combination
Constipation (2.7%), flatulence (1.7%) and headache (1.2%) - most common with loperamide hydrochloride in acute diarrhoea trials
Abdominal pain, abdominal discomfort, abdominal distension, dyspepsia, vomiting, dry mouth (uncommon)
Somnolence, dizziness; rare: loss of consciousness, depressed level of consciousness, stupor, hypertonia, coordination abnormality, miosis
Hypersensitivity reaction, anaphylactic reaction (including anaphylactic shock) and anaphylactoid reaction; rare ileus (including paralytic ileus) and megacolon (including toxic megacolon); rash and bullous eruption (including Stevens-Johnson syndrome); acute pancreatitis (frequency not known)

Interactions

The eMC §4.5 interaction section was truncated at source fetch (text ends at 'Non-clinical') and no interactions were captured - clinician to review §4.5 in the full SPC

Clinical monograph

How it works

Loperamide acts on gut opioid receptors to slow intestinal motility and reduce stool frequency, while simeticone lowers the surface tension of gas bubbles to coalesce and disperse trapped intestinal gas, relieving bloating and flatulence.

Prescribing in practice

As with loperamide alone, avoid in dysentery, suspected bacterial colitis with blood and fever, and active inflammatory bowel disease, where slowing motility risks serious complications including toxic megacolon.
It is for short-term symptomatic use and does not replace oral rehydration, and the loperamide dose must not be exceeded because of the cardiac risks seen in overdose.
Simeticone is essentially non-absorbed and inert, so the combination's cautions are driven principally by the loperamide component.

Monitoring

No routine monitoring is needed; review if symptoms persist beyond a short period or if blood, fever or abdominal distension develop.

Counselling the patient

This combination eases both the diarrhoea and the trapped wind and bloating that can come with it.
Keep up your fluid intake and stop and seek advice if you see blood in the stool, develop a fever, or the tummy becomes swollen.

Evidence & guidelines

The loperamide-simeticone combination is an established over-the-counter option for acute diarrhoea with associated bloating and gas.

Reference: Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways