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MyDeficiencies

Loperamide

peripheral mu-opioid agonist antidiarrheal (antipropulsive)

Also sold as Imodium.

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Findings for this medication

Research about this medication, graded for how strongly each finding can be attributed to it. Nothing here describes your own levels.

Loperamide has almost no classical depletion machinery. At labeled doses it is cleared mainly by oxidative N-demethylation (CYP2C8 and CYP3A4 "thought to play an important role"), unchanged drug and metabolites leave mainly in feces, plasma levels of unchanged drug stay below 2 ng/mL after a 2 mg capsule, and it is a P-glycoprotein substrate [1]. The retrieved label sections describe no CYP induction, no renal tubular effect and no nutrient interaction; the only electrolyte statement is that fluid and electrolyte depletion often occurs in patients who have diarrhea, which is the indication, not the drug [1]. Of the mechanism classes screened, altered transit time (class A) is the one that applies, and it also reaches the gut microbiome (class G): a randomized cross-over in healthy volunteers measured stool microbiome shifts during a 6-day loperamide course [15]. No source retrieved measured a nutrient effect from slowed transit.

peripheral mu-opioid agonist antidiarrheal (antipropulsive) · ATC A07DA03 (WHO ATC/DDD Index [3]) · also sold as Imodium; many generics and store brands · reviewed 2026-10-04. This describes research about the medication. It does not say anything about your own levels or health.

How to read the evidence grades

These colours describe how strongly a finding can be attributed to the medication in the research. They are not a severity score and they say nothing about your own health.

Grades describe how strongly a finding can be attributed to Loperamide in the research — not how common it is, how serious it would be, and not anything about you personally.

Red — Severe
Two or more independent Tier A sources, this drug in the cohort, the nutrient directly measured, consistent direction, clinically meaningful magnitude, a named mechanism, no substantial contradicting Tier A evidence.
Orange — Moderate
At least one Tier A source with this drug in the cohort showing a real but bounded deficit: an exposure window, a subgroup, low frequency, or a functional rather than circulating deficit.
Yellow — Low
Mechanistic plausibility only (Tier B), or class extrapolation (Tier C) with no drug-specific human status data; also used for context flags and interactions running the other direction.
Not graded — disclosed evidence gap
Nothing has been measured here, so this finding cannot be graded. That does not establish either safety or harm, and it is not the same as a White result.Source definition: Not gradeable under the rules above because nothing has been measured. Published as a documented gap, never as reassurance that there is no effect.

What the research found

Potassium and magnesium: indication-linked context flag; QT effect is the drug's own

Yellow — Low

See study details

Diarrhea itself loses fluid and electrolytes, and low potassium or magnesium would add to the QT risk loperamide already carries at high doses, but no study retrieved shows loperamide lowering either mineral.

Full detail and limits

What the grade means here: Mechanistic plausibility only (Tier B), or class extrapolation (Tier C) with no drug-specific human status data; also used for context flags and interactions running the other direction. Yellow

Limits on what this shows

  • Null findings: No controlled comparison of potassium or magnesium in loperamide users was located. No electrolyte values were present in the case and review text read [5][7][8][9], so those sources neither show nor exclude a mineral deficit.
  • At-risk subgroups: People with ongoing diarrhea, people exceeding labeled doses, and people on other QT-prolonging drugs or P-gp inhibitors that raise loperamide exposure 2 to 3 fold [1]. These are context groups, not loperamide-depletion findings.

Regulatory status

The Rx label states that "fluid and electrolyte depletion often occur in patients who have diarrhea" and that replacement is very important; potassium and magnesium are not named [1]. The OTC label carries a heart alert about doses above those directed [2].

Population evidence

No comparative measurement of potassium or magnesium in loperamide users was retrieved. Lammoglia 2022 [5], integrative review of 29 cardiotoxicity cases (doses 12 to 600 mg): QTc prolongation in 27, QRS prolongation in 12, torsades de pointes in 5; it advises evaluating reversible QTc risk factors "such as electrolyte abnormalities such as hypokalemia and hypomagnesemia" but gives no individual electrolyte values in the text read. BMJ case [8]: recurrent polymorphic ventricular tachycardia with more than 100 tablets daily for a year; intravenous magnesium was part of treatment, and no electrolyte values were in the abstract metadata. Jackson 2021 [7]: torsades after up to 100 tablets of 2 mg daily; no electrolyte values in the abstract metadata. Tier B (case reports and review, this drug).

Mechanism

The QT effect has a named mechanism that is not a mineral deficit: blockade of hERG, Nav1.5 and L-type calcium channels by loperamide itself [5]. A mineral loss from loperamide has no demonstrated mechanism; the plausible source of electrolyte loss is the diarrheal illness [1].

Class cohort test

Not applicable: no class extrapolation is used. All sources name loperamide. Data from the same-batch opioid-class antidiarrheal diphenoxylate/atropine are not borrowed.

Counter-evidence held on record

Counter-evidence and confounding Confounding by indication is presumed (Hard Rule 6): the people taking loperamide have diarrhea, which loses fluid and electrolytes regardless of the drug. Torsades and QT prolongation are the drug's own cardiac toxicity (Hard Rule 2) and must not be relabeled as potassium or magnesium deficiency. Framing caution This is a monitoring prompt for people with diarrhea or high-dose exposure, not a deficiency caused by loperamide. Do not recommend potassium or magnesium supplements from this entry; no supplement dose is given. Emergency electrolyte management belongs to treating clinicians.

The five body-system areas

Each finding is counted once, in a single area. Where a study is mentioned in a second area it is context only.

Mitochondrial Burden

Each finding below is counted once, in this area only.

Mitochondrial burden: one mouse constipation-model abstract, attribution unresolved

Yellow — Low

See study details

In mice made constipated with loperamide, colonic smooth muscle showed mitochondrial damage, but the design cannot tell a direct loperamide effect from the effect of being constipated, and no human data were found.

Full detail and limits

What the grade means here: Mechanistic plausibility only (Tier B), or class extrapolation (Tier C) with no drug-specific human status data; also used for context flags and interactions running the other direction. Yellow

Limits on what this shows

  • Null findings: Two other loperamide-model records surfaced by a PubMed mitochondria listing were opened at abstract level and do not support the claim: one neferine study does not mention loperamide [11], and one Cistanche rat study only notes electron-microscopy observation of colonic mitochondria without findings [12].
  • At-risk subgroups: None defined.

Regulatory status

No mitochondrial statement in the label sections retrieved [1][2].

Population evidence

None in humans. Yao 2026 [10]: loperamide-induced functional constipation mouse model; the abstract reports downregulated UPRmt-related genes in colonic smooth muscle cells accompanied by mitochondrial damage, with HSF1 overexpression and knockdown altering the pathway and motility. Read as abstract-level text through the OpenAlex record, summarized by a fetch tool; the full text was not opened, and the abstract text seen does not state loperamide dose, duration or the control group. Tier B (animal study using this medication).

Mechanism

The authors frame mitochondrial dysfunction as associated with the disease state of functional constipation. Loperamide served as the tool that induces the state. A direct mitochondrial action of loperamide on tissue is not demonstrated in the text read.

Counter-evidence held on record

Counter-evidence and confounding The intended pharmacologic effect of loperamide is reduced intestinal transit. Changes found in constipated tissue are a downstream state, not evidence of a mitochondrial toxicity independent of that state. Human therapeutic plasma levels of unchanged drug are very low [1]. Framing caution Not a claim that loperamide damages mitochondria in people. No supplement is implied.

Oxidative Stress

Each finding below is counted once, in this area only.

Oxidative stress: tissue ROS in a mouse constipation model, same single source

Yellow — Low

See study details

The same loperamide-constipation mouse study reports elevated reactive oxygen species in colonic smooth muscle; no human systemic redox marker was found, and the effect cannot be separated from the constipated state.

Full detail and limits

What the grade means here: Mechanistic plausibility only (Tier B), or class extrapolation (Tier C) with no drug-specific human status data; also used for context flags and interactions running the other direction. Yellow

Limits on what this shows

  • Null findings: The hemp-seed loperamide-constipation abstract [13] does not discuss oxidative stress. No human redox study with loperamide was located.

Regulatory status

No oxidative-stress statement in the label sections retrieved [1][2].

Population evidence

None in humans. Yao 2026 [10], abstract level: mitochondrial damage "accompanied by" reduced ATP production and elevated ROS in colonic smooth muscle of the loperamide-induced constipation model. The ROS measure is a local tissue finding; no glutathione, malondialdehyde or total antioxidant capacity values were in the text seen. Tier B.

Mechanism

Not demonstrated for the drug itself; ROS rise is reported alongside mitochondrial dysfunction in the disease model [10].

Counter-evidence held on record

Counter-evidence Shares its only source with the mitochondrial and ATP entries, so it is not independent confirmation (see Overlap map). Direction and size in humans are unknown. Framing caution Do not describe loperamide as depleting antioxidants or causing oxidative damage. No antioxidant supplement is implied.

Copper and Iron Balance

Copper and iron are assessed separately. Nothing here is counted twice.

Copper

Not graded — disclosed evidence gap

See study details

No evidence on loperamide and copper status or copper handling was retrieved.

Full detail and limits

What the grade means here: Nothing has been measured here, so this finding cannot be graded. That does not establish either safety or harm, and it is not the same as a White result. Ungraded

Limits on what this shows

  • Why no grade: Dual condition met: no Tier B or C source was found to support even a yellow grade, and no circulating copper claim for loperamide was located to rebut. This is a disclosed gap, not a finding of safety. Kept independent of Iron (Hard Rule 7). Re-check with a second phrasing when access improves.

What was searched

DailyMed Rx label (no copper mention in the sections read) [1]; PubMed listing "loperamide copper" (opened; six unrelated records, mostly copper sulphate emesis models in ferrets and a P-gp imaging review, none about copper status in loperamide users); one consumer depletion-page URL for loperamide (404). Only one copper phrasing was run on PubMed. Second pass 2026-10-04: the Rx and OTC labels were re-read through a summarizing fetch tool and returned "not present" for copper [1][2]; Europe PMC title lists for "loperamide iron" and "loperamide anemia" (20 records each, opened as lists only) contained no copper or iron-status study of loperamide users. A dedicated Europe PMC copper query was not completed because of repeated 429 responses.

Channel outcomes

Web search budget exhausted (200 of 200). Crossref, Europe PMC, Semantic Scholar, direct PubMed eutils and accessdata.fda.gov were blocked by policy and not routed around. Mixed result: a clean zero on the channels that worked, with thin coverage. Tooling-limited rather than a proven literature gap.

Iron

Not graded — disclosed evidence gap

See study details

No evidence that loperamide changes iron absorption or iron status was retrieved.

Full detail and limits

What the grade means here: Nothing has been measured here, so this finding cannot be graded. That does not establish either safety or harm, and it is not the same as a White result. Ungraded

Limits on what this shows

  • Why no grade: Dual condition met: no Tier B or C source supports loperamide altering iron handling, and no circulating iron claim for loperamide was found (the one iron statement retrieved concerns a different agent, see Fails verification). Anemia would be an outcome, not an iron finding (Hard Rule 2). This is not a finding of safety.

What was searched

DailyMed Rx label (iron not named) [1]; PubMed listing "loperamide iron absorption" (opened; two records). A 2013 Belgian review of acute diarrhea treatment [14] attributes "diminished iron absorption" and anemia risk to gelatin tannate, not loperamide. A second record, a pediatric surgical case in which some patients had iron deficiency at follow-up, was seen as a title and summary only and not opened; it is confounded by surgery and was not used. Second pass 2026-10-04: Rx and OTC labels returned "not present" for iron, anemia, hemoglobin and hematologic adverse reactions [1][2]; Europe PMC "loperamide iron" (20 records) and "loperamide anemia" (20 records) title lists were opened and none concerned iron absorption or iron status in loperamide users (hits were constipation-model studies, reviews, oncology toxicity papers and unrelated cases).

Channel outcomes

One iron phrasing succeeded; a hemoglobin phrasing returned 429 and was not retried. Other database hosts blocked. Tooling-limited, with a likely thin literature.

Gut Microbiome Risk

Each finding below is counted once, in this area only.

Gut microbiome risk: composition and function shift during a 6-day course in 18 healthy volunteers, reversed within 16 days, transit-mediated

Orange — Moderate

See study details

In a randomized cross-over of healthy volunteers, 6 days of loperamide slowed whole gut transit and shifted the stool microbiome (higher species richness, more bile salt hydrolase genes), and the shift reverted within 16 days. The authors attribute it to slowed transit, the drug's intended effect. It is a change in composition, not a demonstrated harm, and long-term or patient data were not found.

Full detail and limits

What the grade means here: At least one Tier A source with this drug in the cohort showing a real but bounded deficit: an exposure window, a subgroup, low frequency, or a functional rather than circulating deficit. Orange

Limits on what this shows

  • Null findings: The mouse study found no significant difference in alpha diversity or in the phylum-level Firmicutes/Bacteroidetes ratio between loperamide-only and control animals [13], so the human richness increase [15] was not replicated in that model. No human loperamide study of small intestinal bacterial overgrowth or of C. difficile risk was retrieved; a Europe PMC listing for loperamide with iron returned a 2026 pharmacopoeia-wide C. difficile case-cohort title (PMID 41830216) that could not be opened (429) and is not cited.
  • At-risk subgroups: None defined by the sources. Evidence covers short exposure in healthy adults; chronic use, children, inflammatory bowel disease and people with infectious diarrhea were not studied in the sources read.

Regulatory status

No microbiome statement in the labels retrieved. The Rx label lists infection-related contraindications that are the drug's own hazard when transit is slowed in an infected or inflamed bowel: "bacterial enterocolitis caused by invasive organisms including Salmonella, Shigella, and Campylobacter", "pseudomembranous colitis associated with the use of broad-spectrum antibiotics", acute ulcerative colitis, and "possible risk of significant sequelae including ileus, megacolon and toxic megacolon" [1]. Clostridium difficile is not named in the Rx text, and none of these topics appear in the 2026 OTC label, which warns only about bloody or black stool [2]. Label text re-read 2026-10-04 through a summarizing fetch tool, so wording is as relayed. These are outcomes of the drug's action, not microbiome measurements.

Population evidence

Tier A: Hillman 2025 [15], randomized cross-over, healthy volunteers (n = 18). Loperamide "to decrease bowel movement frequency" and senna were each given for 6 days in random sequence with at least 16 days between treatments; stool microbiome by shotgun sequencing. Reported: loperamide increased whole gut transit time; "Increasing WGTT with loperamide led to an increase in bile salt hydrolase genes, along with elevated bacterial species richness (p = 0.04)"; thirty-six species showed significant differences (the abstract does not say which treatment contrast that count refers to); transit time correlated negatively with total primary and secondary fecal bile acids; "Treatment-induced changes in microbiome composition and bile acid metabolism reverted back to baseline within 16 days." Abstract level only: loperamide dose, any placebo or baseline period, effect sizes, confidence intervals and taxa names were not seen (PMC full text not opened, 429). Tier B: Huang 2024 [13], BALB/c mice, 10 per group, loperamide 10 mg/kg by gavage daily for 2 weeks versus saline controls, 16S sequencing: Shannon and evenness indexes and the Firmicutes/Bacteroidetes ratio (1.14 versus 0.99) did not differ significantly; Bacteroides and Odoribacter proportions were significantly lower and Roseburia and Lachnospiraceae enriched in the loperamide group; constipation was confirmed by lower fecal water, later first defecation and slower small-intestinal transit.

Mechanism

Slowed colonic transit (mechanism classes A and G): the human study's conclusion is that whole gut transit time changes fecal microbiome composition and function, with senna, which shortened transit, associated with higher fecal bile acids and lower serum FGF19, and the mouse authors describe microbiota disturbance as a feature of constipation [13][15]. A direct action of loperamide on microbes was not tested in either source.

Class cohort test

Not applicable: no class extrapolation. Loperamide was the administered drug in both [13] and [15]. Data from the senna arm of [15] are not used for loperamide.

Counter-evidence held on record

Counter-evidence and confounding The microbiome shift follows from the drug's intended antipropulsive effect (Hard Rule 2), so it is a downstream state of slowed transit, not evidence of microbial toxicity; the mouse comparison cannot separate loperamide from the constipated state. Confounding by indication applies to patients, because diarrheal illness itself alters the microbiome (Hard Rule 6), and neither source studied patients. Richness rose in the human study, which is not by itself an adverse change, and no functional outcome such as infection or short-chain fatty acid output was measured in the abstract read. Framing caution Do not present this as dysbiosis, gut damage or a deficiency, and do not imply a probiotic or supplement is needed; no supplement dose is given. The infection-related labeled warnings are about using loperamide during invasive or antibiotic-associated colitis, which is a prescriber and pharmacist question.

Oxygen and ATP Output

Oxygen delivery and ATP production are assessed separately. Nothing here is counted twice.

ATP production: reduced ATP in mouse colonic smooth muscle, same single source

Yellow — Low

See study details

The loperamide-constipation mouse study reports reduced ATP production in colonic smooth muscle; this is a tissue finding in a disease model and not evidence of reduced cellular energy output in people taking loperamide.

Full detail and limits

What the grade means here: Mechanistic plausibility only (Tier B), or class extrapolation (Tier C) with no drug-specific human status data; also used for context flags and interactions running the other direction. Yellow

Limits on what this shows

  • Null findings: None located.

Regulatory status

No energy-metabolism statement in the label sections retrieved [1][2].

Population evidence

None in humans. Yao 2026 [10], abstract level: reduced ATP production in the colonic smooth muscle of the loperamide-induced constipation model. The assay used and the comparison group were not stated in the abstract text seen. Tier B.

Mechanism

Linked by the authors to impaired mitochondrial stress response in the constipated tissue; not shown as a direct effect of loperamide [10].

Counter-evidence held on record

Counter-evidence Kept as its own entry per Hard Rule 7, but it rests on the same abstract as Mitochondrial burden and Oxidative stress. Reduced intestinal muscle ATP in a stasis model is not a "low energy" claim for people. Framing caution Not a fatigue or low-energy claim. No supplement is implied.

Oxygen delivery/utilization

Not graded — disclosed evidence gap

See study details

No evidence that loperamide reduces hemoglobin, red-cell mass or tissue oxygen delivery was retrieved.

Full detail and limits

What the grade means here: Nothing has been measured here, so this finding cannot be graded. That does not establish either safety or harm, and it is not the same as a White result. Ungraded

Limits on what this shows

  • Why no grade: Dual condition met: no Tier B or C evidence on oxygen carrying or utilization and no circulating claim found. Any anemia effect would route through the iron entry and is not double-counted. Kept independent of ATP production (Hard Rule 7). This is not a finding of safety.

What was searched

DailyMed Rx label adverse reactions as summarized (allergic reactions, paralytic ileus, megacolon, drowsiness, urinary retention; no hematologic effect listed) [1]. PubMed listing "loperamide hemoglobin anemia" returned 429 and was not retried. Overdose CNS depression and cardiac arrhythmia are the drug's own toxicity and are not oxygen-delivery findings (Hard Rule 2). Second pass 2026-10-04: Rx and OTC labels re-read, hemoglobin, anemia and hematologic adverse reactions "not present" [1][2]; Europe PMC "loperamide anemia" title list (20 records) held no study of loperamide and hemoglobin, red-cell mass or tissue oxygenation (one 2026 case of overdose cardiac arrest, a drug-toxicity report, was seen as a title only).

Channel outcomes

One phrasing blocked; web search exhausted; database hosts blocked. Tooling-limited.

Claims checked and not supported

These circulate online for this medication. They are listed here only so they can be answered, never as findings, and they are not graded.

A claim with no supporting evidence is not necessarily disproven. Where evidence actually argues against a claim, that is stated below.

  • Circulating-claim audit status (not a claim)

    Where it comes from: Step 6 audit. Web search budget was exhausted; one consumer depletion-page URL for loperamide returned 404; no consumer page was opened.

    Why it fails: No circulating consumer claim was traced, so none is rebutted here. Claims may exist elsewhere, and a re-check should query consumer depletion lists and retailer pages for loperamide.

  • Cardiac toxicity filed as potassium or magnesium deficiency

    Where it comes from: Not a retrieved consumer claim. Included as a Hard Rule 2 clarification because the cardiac literature [5] discusses electrolytes as risk modifiers.

    Why it fails: QT prolongation and torsades at high doses follow from loperamide's own hERG, Nav1.5 and L-type calcium channel blockade [5][6]. Electrolytes modify the risk; they are not shown to be lowered by the drug. See the yellow potassium and magnesium entry.

  • Labeled infection or megacolon warnings filed as microbiome damage

    Where it comes from: Not a retrieved consumer claim. Included as a clarification because the Rx label lists enterocolitis, pseudomembranous colitis and megacolon in its contraindications and warnings [1].

    Why it fails: These are the drug's own hazard when transit is slowed in an infected or inflamed bowel, not a measured change in the microbiome. The microbiome entry rests on [13][15], not on these label statements.

  • Iron malabsorption and anemia

    Where it comes from: Not a loperamide claim. A retrieved 2013 review of diarrhea treatments [14] states "diminished iron absorption" with risk of anemia for gelatin tannate.

    Why it fails: The statement is attributed to gelatin tannate in the abstract read, not to loperamide. Shown so that it is not misattributed to loperamide. Loperamide iron status is ungraded.

How the body handles this medication

Metabolism and enzymes
Elimination mainly by oxidative N-demethylation; CYP2C8 and CYP3A4 are "thought to play an important role." An integrative review describes intestinal and hepatic CYP3A4 and CYP2C8 metabolism to inactive metabolites. No CYP induction or inhibition by loperamide appears in the label sections retrieved.[1] DailyMed Rx label, Clinical Pharmacology; [5]
Elimination
Unchanged loperamide and metabolites are excreted mainly in feces. Apparent elimination half-life 10.8 hours (range 9.1 to 14.4) in the label; 9 to 30 hours in the review. No renal dose adjustment is stated.[1][5]
Absorption and transporter
Peak plasma level about 5 hours after a capsule and 2.5 hours after liquid. Unchanged drug stays below 2 ng/mL after a 2 mg capsule. It is a P-glycoprotein substrate; P-gp efflux limits brain penetration, and at high doses P-gp saturation allows central effects. A numeric oral bioavailability figure was not present in the label text retrieved.[1][5]
Interactions
P-gp inhibitors (quinidine, ritonavir) raise loperamide plasma levels 2 to 3 fold. No food, mineral or antacid interaction is listed in the sections retrieved. The OTC caplet lists calcium 15 mg as an ingredient per caplet, which is a formulation content, not an interaction.[1][2]
Hepatic, renal, special groups
Use with caution in hepatic impairment because of reduced first-pass metabolism. No renal adjustment. Not recommended below 24 months (Rx label) or under 2 years (OTC label). The Rx label gives pregnancy category C.[1][2]
Fluid, electrolytes and cardiac channels
Label: fluid and electrolyte depletion often occurs in diarrhea and replacement is important. Cardiac toxicity at supratherapeutic doses involves hERG (Kv11.1), Nav1.5 and L-type calcium channel blockade. Naloxone does not reverse the hERG effect in a reported case. The 2026 OTC label warns that taking more than directed can cause serious heart problems or death.[1][2][5][6]

What the research says is worth watching

General information from the medication label and the studies above. It is not personal medical advice, and any change belongs with your prescriber.

  • Cardiac / dose

    Stay within labeled doses

    OTC label: adults and children 12 and over, no more than 4 caplets in 24 hours; the Rx label states a daily maximum of 16 mg [1][2]. Reported cardiac events involved 12 to 600 mg single ingestions and 64 to 1600 mg daily, with serum levels of 22 to 210 ng/mL [5][9]. Syncope, palpitations or dizziness after high or repeated use warrants urgent ECG evaluation of QTc; naloxone does not reverse the hERG effect [6].

  • Lab / context

    Potassium and magnesium

    Worth checking when diarrhea is ongoing, when QT-prolonging drugs are co-prescribed, or after high-dose exposure [1][5]. This is a risk-modifier check, not evidence that loperamide lowers either mineral. No supplement dose is recommended.

  • Interactions

    P-gp inhibitors and liver function

    Quinidine and ritonavir raise loperamide plasma levels 2 to 3 fold [1]. Caution in hepatic impairment because of reduced first-pass metabolism [1].

  • Fluid status

    Rehydration in diarrhea

    The label emphasizes fluid and electrolyte replacement during diarrhea [1]. Persistent diarrhea beyond 2 days or bloody or black stool is a stop-and-seek-care signal on the OTC label [2].

  • Timing

    Supplement separation

    No separation interval or mineral interaction is listed in the sections retrieved [1][2]. No supplement dose appears anywhere in this dossier, so no upper-limit comparison was needed.

  • Special populations

    Pregnancy, pediatrics, renal

    Rx label (2005 text): pregnancy category C, not recommended below 24 months, no renal dose adjustment [1]. The OTC label advises professional guidance in pregnancy or nursing and no use under 2 years [2]. Current pregnancy labeling was not verified.

Overlap map, to prevent double counting

  • Mitochondrial burden

    Shares evidence with: Oxidative stress; ATP production

    Note: All three rest on the single abstract of Yao 2026 [10], one mouse model of loperamide-induced constipation. Treat as one line of evidence and one caveat (state versus drug effect), not three confirmations.

  • Potassium and magnesium

    Shares evidence with: Cardiac toxicity sources [5][6][7][8][9]

    Note: The same reviews and cases that document the QT effect supply the electrolyte discussion. They show a risk modifier, not independent evidence of a mineral deficit.

  • Copper

    Shares evidence with: Iron

    Note: No shared evidence source. Both ungraded after the same blocked-channel search conditions; graded separately per Hard Rule 7.

  • Oxygen delivery/utilization

    Shares evidence with: Iron; ATP production

    Note: Any oxygen-carrying effect would be mediated by iron; ATP evidence [10] is a tissue finding and is not used for oxygen delivery. Entries kept separate per Hard Rule 7.

  • Gut microbiome risk

    Shares evidence with: Oxidative stress (citation only, [13])

    Note: Evidence is Hillman 2025 [15] (Tier A, human) and Huang 2024 [13] (Tier B, mouse); both rest on slowed transit, so they are two models of one effect, not independent confirmations. [13] is also cited as a null finding in the Oxidative stress entry but supplies no evidence there. The entry is independent of Yao 2026 [10], though both mouse models share the loperamide-constipated state as a confounder; no data are borrowed between them.

  • All entries

    Shares evidence with: Diphenoxylate/atropine (same-batch sibling)

    Note: Cross-reference only. No diphenoxylate or atropine data were retrieved or borrowed for any entry; the opioid-class antidiarrheal comparison fails the cohort test because no loperamide source above included diphenoxylate. Compare the sibling dossier for its own findings.

All references used above
  1. IMODIUM (loperamide hydrochloride) capsule, Rx, DailyMed label. — Regulatory label (Tier A). Text revised 1996, 1998, 2004, approved October 2005; contains no cardiac or QT warning. Clinical Pharmacology, Precautions, Adverse Reactions, Drug Interactions read via a summarizing fetch tool, so wording is as relayed by that tool. Numeric bioavailability not seen.Older label text; superseded safety communications not seen. Read via summarizing fetch tool.
  2. LOPERAMIDE HCL tablet, OTC, DailyMed label. — Regulatory label (Tier A). Revision date shown July 10, 2026. Heart alert, maximum dose, ingredient calcium 15 mg per caplet. Read via summarizing fetch tool.
  3. WHO Collaborating Centre, ATC/DDD Index: loperamide, A07DA03, DDD 10 mg oral. — Reference index. Parent group A07DA antipropulsives.
  4. ClinCalc DrugStats: Loperamide. — Usage statistics, 2024 data: rank 238 of the Top 300, about 1.77 million estimated prescriptions. Reference only.
  5. Lammoglia BC, et al. Risk of cardiac lesion with chronic and acute use of loperamide, an integrative review. J Cardiovasc Dev Dis 2022;9(12):431. — Integrative review, 29 cases (doses 12 to 600 mg). DOI 10.3390/jcdd9120431. PMID 36547428. Full text opened through the MDPI page via a summarizing fetch tool; abstract confirmed via the OpenAlex record (which states 27 cases with QTc prolongation).Narrative synthesis of case reports; no comparator or nutrient measurement.
  6. Isang E, Shali L, Morris CB, Mahlow J. Loperamide-induced torsades de pointes. Cureus 2021. — Case report, one patient, 96 mg; QTc 560 then 656 ms; torsades. DOI 10.7759/cureus.20299. PMID 35028205. Abstract via the OpenAlex record, summarized by a fetch tool.
  7. Jackson GG, et al. Loperamide induced recurrent torsades de pointes: a case report. J Pharm Pract 2021. — Case report, one patient, up to 100 tablets of 2 mg daily for 5 years. DOI 10.1177/08971900211004832. PMID 33779357. Abstract via the OpenAlex record; electrolyte values not present in that metadata.
  8. Iqbal S, Fayyaz SM, Saeed Y, Aqeel M. Loperamide-induced cardiotoxicity: a case overlooked? BMJ Case Rep 2021. — Case report, one patient, more than 100 tablets daily for a year; intravenous magnesium given. DOI 10.1136/bcr-2021-243325. PMID 34290024. Abstract via the OpenAlex record; electrolyte values not present in that metadata.
  9. de Lemos ML, Guenter J, Kletas V. Loperamide and cardiac events: is high-dose use still safe for chemotherapy-induced diarrhea? J Oncol Pharm Pract. — Narrative pharmacy review. Cases at 64 to 1600 mg daily, serum levels 22 to 210 ng/mL. DOI 10.1177/1078155217718384. PMID 28714380. Year shown as 2017 by OpenAlex and 2018 in the PubMed listing. Abstract via the OpenAlex record.
  10. Yao J, Wang W, Zhang W, Dong H, Hou Y, Zheng Q, Li Y, Zeng F. Dysregulation of the HSF1-mediated UPRmt pathway in colonic smooth muscle cells drives motility dysfunction in functional constipation. Biomolecules 2026 (June 12). — Mouse study, loperamide-induced functional constipation model. DOI 10.3390/biom16060868. PMID 42352334. Abstract only, via the OpenAlex record summarized by a fetch tool; full text not opened.Loperamide used as the constipation inducer; drug effect not separated from disease state.
  11. Chen T-Y, et al. Neferine ameliorates slow-transmitting constipation by inducing PINK1/Parkin-mediated mitophagy in protective enteric glial cells. J Microbiol Biotechnol 2025. — Rat/cell study. DOI 10.4014/jmb.2412.12022. PMID 40295194. Abstract via OpenAlex.Excluded: the abstract read does not mention loperamide. Not used as evidence.
  12. Zhang X, Zheng F-J, Zhang Z. Therapeutic effect of Cistanche deserticola on defecation in senile constipation rat model through stem cell factor/C-kit signaling pathway. World J Gastroenterol 2021. — Rat study. DOI 10.3748/wjg.v27.i32.5392. PMID 34539140. Abstract via OpenAlex; mitochondria observed by electron microscopy, no findings stated.Excluded as evidence: abstract states no mitochondrial finding, and the constipation-induction agent was not stated in the abstract read.
  13. Huang H, Wang Y, Ding X, et al. Hemp seeds attenuate loperamide-induced constipation in mice. Front Microbiol 2024;15:1353015. — Mouse intervention study, 4 groups of 10 female BALB/c mice; loperamide 10 mg/kg by gavage daily for 2 weeks in the model group versus saline controls; 16S rRNA sequencing (NovaSeq 6000, QIIME2). DOI 10.3389/fmicb.2024.1353015. PMID 38638898. Abstract first read via OpenAlex; full text opened on 2026-10-04 on the Frontiers page through a summarizing fetch tool, so wording is as relayed. Tier B for the microbiome entry (loperamide-only versus control arm).Loperamide was used to induce constipation, so the microbiome difference between loperamide-only and control animals cannot be separated from the constipated state. The abstract read did not discuss oxidative stress; the full text was not searched for it. First-author initials listed earlier as "Hua H" were corrected to Huang H on opening the full text.
  14. Leemans L. The treatment of acute diarrhea [in French/Dutch]. J Pharm Belg 2013. — Narrative review. PMID 24804407. Abstract via OpenAlex. Iron absorption and anemia statement attributed to gelatin tannate.Excluded cohort: statement does not concern loperamide. Abstract read through OpenAlex, not the PubMed page.
  15. Hillman EBM, Baumgartner M, Carson D, Amos GCA, Wazir I, Khan HA, Khan MA, Rijpkema S, Walters JRF, Wellington EMH, Arasaradnam R, Lewis SJ. Changing gastrointestinal transit time alters microbiome composition and bile acid metabolism: a cross-over study in healthy volunteers. Neurogastroenterol Motil 2025;37(10). — Randomized cross-over, 18 healthy volunteers; loperamide and senna 6 days each, at least 16 days apart; shotgun stool metagenomics and bile acid profiling. Tier A (loperamide in the cohort). DOI 10.1111/nmo.70075. PMID 40394972. PMCID PMC12435802. Funding: DHSC Policy Research Programme (NIBSC Regulatory Science Research Unit). Abstract read verbatim from the Europe PMC record through a summarizing fetch tool on 2026-10-04.Not opened beyond the abstract: the Wiley page returned 403 and the PMC page returned 429. Loperamide dose, placebo or baseline design, effect sizes, confidence intervals and taxa names unverified.