Loperamide

Loperamide

Clinical data
Pronunciation	/loʊˈpɛrəmaɪd/
Trade names	Imodium, others[1]
Other names	R-18553, Loperamide hydrochloride (USAN US)
AHFS/Drugs.com	Monograph
MedlinePlus	a682280
License data	US DailyMed: Loperamide
Pregnancy category	AU: B3
Routes of administration	By mouth
ATC code	A07DA03 (WHO) A07DA05 (WHO) (oxide)
Legal status
Legal status	AU: S2 (Pharmacy medicine) BR: Class C1 (Other controlled substances) [2] CA: OTC UK: General sales list (GSL, OTC) US: OTC / Rx-only[3][4] SE: OTC
Pharmacokinetic data
Bioavailability	<1%[5]
Protein binding	~95-97%[6]
Metabolism	Liver (extensive)
Metabolites	N-Desmethyloperamide, Loperamide-N-oxide, Loperamide carbinolamide metabolite[7]
Onset of action	~1 hour[8]
Elimination half-life	9–14 hours[9]
Duration of action	Up to 3 days[10]
Excretion	Feces (30–40%), urine (1%)
Identifiers
IUPAC name 4-[4-(4-Chlorophenyl)-4-hydroxypiperidin-1-yl]-N,N-dimethyl-2,2-diphenylbutanamide
CAS Number	53179-11-6
PubChem CID	3955
IUPHAR/BPS	7215
DrugBank	DB00836
ChemSpider	3818
UNII	6X9OC3H4II
KEGG	D08144
ChEBI	CHEBI:6532
ChEMBL	ChEMBL841
CompTox Dashboard (EPA)	DTXSID6045165
ECHA InfoCard	100.053.088
Chemical and physical data
Formula	C29H33ClN2O2
Molar mass	477.05 g·mol−1
3D model (JSmol)	Interactive image
Solubility in water	The water solubility of loperamide is approximately 0.14 g/100 mL at room temperature.CID Loperamide from PubChem
SMILES ClC1=CC=C(C2(CCN(CC2)CCC(C3=CC=CC=C3)(C(N(C)C)=O)C4=CC=CC=C4)O)C=C1
InChI InChI=1S/C29H33ClN2O2/c1-31(2)27(33)29(24-9-5-3-6-10-24,25-11-7-4-8-12-25)19-22-32-20-17-28(34,18-21-32)23-13-15-26(30)16-14-23/h3-16,34H,17-22H2,1-2H3 Key:RDOIQAHITMMDAJ-UHFFFAOYSA-N

Loperamide hydrochloride (Brand nameː Imodium)^[11][12] is a man-made (synthetic) drug that treats diarrhoea and irritable bowel syndrome (IBS). It is taken orally, as tablets or capsules, liquid suspension (1mg/7.5mL)^[13] and also comes in formations that melt on the tongue.^[11] The tablets are 2mg each.^[11][13] It is available OTC (over the counter)^[13] in most countries including the UK and USA.

The drug is taken to treat diarrhoea short-term but can be used long-term to treat symptoms of some bowel conditions, in Crohn's disease, ulcerative colitis, and short bowel syndrome, for example.^[11] It is also given to patients after some types of surgery, for example it is used in high doses after a colonoscopy to make the bowel movements (poo) less runny. Imodium is also indicated for treating high amounts of fecal discharge in ileostomies.^[11] It reduces symptoms normally around 1 hour after taking it.^[12]

Loperamide does not treat underlying causes. This means it only treats symptoms, but does not make what is causing diarrhoea go away,^[11] if there is an underlying cause. There may be side-effects from the underlying cause not related to the medicine, but using loperamide can causeː^[12]

• Constipation
• Nausea (feeling sick)
• Headaches
• Gas (farting)
• Abdominal distension^[12]
• Ileus^[12]
• Dry mouth^[11]

When it is used with children, the drug has many different effects, or a high range of results or side effects, and is not safe to use in children.^[11] People with AIDS treated with loperamide for diarrhea may see abdominal distension and should stop therapy if this happens.^[12]

The IUPAC name for loperamide is 4-(p-chlorophenyl)-4-hydroxy-N, N-dimethyla, a-diphenyl-1-piperidinebutyramide, and can be attached to a monohydrochloride (one hydro-chloride) salt or base.

Loperamide can be sold as a combination medication, under the brand name simeticone, to treat flatulence (farting). When it is in this form it is combined with a soap to treat two symptoms at once. As simethicone its structure has a silicon dioxide attached, which is not physiologically active.