Amlodipine

Limits on what this shows

• Key negative or null findings: No study reviewed found amlodipine impairing mitochondrial structure, membrane potential, or biogenesis under normal (non-ischemic) conditions in any tissue. No case reports of amlodipine-associated mitochondrial myopathy, mitochondrial DNA depletion, or a statin-like coenzyme Q10-mediated mitochondrial toxicity were located; amlodipine does not inhibit HMG-CoA reductase (see the Direction-reversed interactions entry above), which is the mechanism statins use to impair the mitochondrial electron transport chain.
• At-risk subgroups: None identified. The protective effect was demonstrated only under experimentally induced ischemic injury, not as a baseline effect in healthy tissue.

Regulatory status

Not addressed by the FDA label. Mitochondrial function is not a monitored parameter for amlodipine.

Population evidence

In vitro study, rodent embryonic neural stem cells (five independent experiments per assay) subjected to oxygen-glucose deprivation (an ischemia model), with and without 0.1-1 uM amlodipine camsylate. Amlodipine-treated cells showed higher survival, mitochondrial membrane potential restored to near-normal (JC-1 assay), reduced intracellular and mitochondrial calcium influx (Fura-2-AM/Fluo-4-AM), reduced reactive oxygen species production (DCFH-DA, concentration-dependent), and increased expression of mitochondrial biogenesis proteins (PGC-1alpha, NRF-1, Mfn1/2). A separate rabbit study (see the Oxidative stress entry below) found amlodipine increased mitochondrial superoxide dismutase activity in heart tissue on a high-cholesterol diet. Both are Tier B, non-human, and neither represents a general, unstressed physiological condition.

Mechanism

This is amlodipine's own documented pharmacology, not a nutrient-status effect: blocking L-type voltage-gated calcium channels reduces calcium influx into the cell and into mitochondria, which under injury conditions prevents mitochondrial permeability transition pore opening and cytochrome c release (the trigger for apoptosis), and secondarily activates the PI3K/Akt survival pathway. Per this protocol's hard rule against filing a drug's intended pharmacological action as a nutrient finding, this is reported here as mechanism, not as evidence that amlodipine protects or depletes any specific nutrient's mitochondrial role.

Counter-evidence held on record

All located mitochondrial data on amlodipine point toward protection under stress, not burden, and the two supporting studies are non-human and injury-specific (ischemia, high-cholesterol diet), not evidence of an effect in an ordinary, unstressed person taking amlodipine for routine hypertension. This must not be marketed as amlodipine "boosting mitochondria" or as a reason to expect more cellular energy. It is calcium-channel pharmacology demonstrated in an injury model, not a nutrient-status finding, and it carries no dosing or supplement implication.

Limits on what this shows

• Key negative or null findings: A cross-sectional study of 30 hypertensive patients already on amlodipine versus 30 healthy controls found the amlodipine-treated group still had significantly higher salivary MDA and significantly lower salivary SOD than healthy controls, with no untreated-hypertensive comparison arm. This does not contradict the finding that amlodipine reduces oxidative stress relative to no treatment; it shows that treated hypertensive patients remain more oxidatively stressed than people who never had hypertension, which is a disease-severity and confounding-by-indication point, not evidence that amlodipine itself adds oxidative burden. A comparative trial of valsartan versus amlodipine in type 2 diabetic hypertensive patients, reported in a peer-reviewed nephrology journal, was located and its existence confirmed via indexing, but this review could not open its full text or abstract (automated access-verification block); no statistic from it is cited.
• At-risk subgroups: None identified as being placed at higher oxidative-stress risk by amlodipine specifically; the consistent direction across all verifiable sources is neutral to protective.

Regulatory status

Not addressed by the FDA label; oxidative stress markers are not a monitored parameter.

Population evidence

Randomized three-month trial, 40 men (30-50 years) with newly diagnosed essential hypertension, 20 on amlodipine 5 mg alone: malondialdehyde (MDA, lipid peroxidation) fell from 2.07 to 1.07 nmol/mL (p<0.001), superoxide dismutase (SOD) rose from 0.0704 to 0.1582 U/100 mL (p<0.001), and erythrocyte Na+K+ATPase activity rose (p<0.001), alongside the expected blood-pressure reduction. A separate rabbit study (n=36, 5 mg/kg/day amlodipine for 8 weeks) found amlodipine reversed high-cholesterol-diet-induced increases in blood TBARS/MDA and restored blood SOD and cardiac glutathione peroxidase and mitochondrial SOD activity (p<0.05). A stroke-prone spontaneously hypertensive rat study found 30 days of oral amlodipine reduced TBARS in four brain regions (p<0.05) and reduced urinary norepinephrine, alongside blood-pressure lowering.

Mechanism

Proposed as a direct chemical property of amlodipine, not a nutrient-sparing or nutrient-replenishing effect: its lipophilic dihydropyridine structure inserts into cell membranes near conjugated double bonds and donates protons to lipid peroxide radicals, chemically interrupting lipid peroxidation, independent of any vitamin or mineral cofactor. Blood-pressure lowering itself, and increased nitric-oxide bioavailability, were also proposed as contributing, indirect mechanisms.

Counter-evidence held on record

No Tier A or Tier B source located shows amlodipine increasing oxidative stress markers relative to an untreated or placebo comparator. The one study showing elevated markers in amlodipine users (versus healthy, never-hypertensive controls) lacked an untreated-hypertensive arm, so it cannot separate a drug effect from the underlying disease. This entry exists to document that no oxidative-stress depletion mechanism was found, not to promote amlodipine as an antioxidant therapy. It should not be used to suggest a consumer can skip dietary antioxidants, and no supplement dose is implied.

Limits on what this shows

• Key negative or null findings: A separate randomized, placebo-controlled, double-blind trial in 62 thalassemia major patients (59 completing) found the opposite tissue-level direction: amlodipine 5 mg/day (2.5 mg/day if body weight 30 kg or under) added to standard iron chelation for 12 months reduced myocardial iron concentration by MRI in iron-overloaded patients (median -0.26 mg/g, p=0.02), with no significant effect on liver iron or serum ferritin. The authors' proposed mechanism was L-type calcium-channel blockade preventing non-transferrin-bound iron from entering cardiomyocytes, a pathway that is only active when non-transferrin-bound iron is circulating, which happens in iron overload, not in the general population. This trial did not measure and does not directly contradict serum iron, hemoglobin, or hematocrit; it shows amlodipine's iron-related effects are tissue- and context-dependent rather than a single uniform mechanism.
• At-risk subgroups: Hemodialysis patients on erythropoiesis-stimulating therapy, and heart-failure patients with pre-existing iron deficiency. Neither study establishes a signal in iron-replete, non-CKD, non-HF adults taking amlodipine for uncomplicated hypertension.

Regulatory status

Not addressed by the FDA label. No iron-related warning, precaution, or laboratory finding is listed for amlodipine.

Population evidence

(1) Retrospective multicenter observational study, hemodialysis patients: 27 patients on amlodipine for 6 or more months versus 61 not on amlodipine, groups balanced for sex, age, dialysis vintage, and comorbidity. Intravenous iron was prescribed to 81.5% of amlodipine users versus 34.4% of non-users, at a median dose of 200 mg/month versus 50 mg/month; continuous erythropoietin receptor activator (CERA) use was 92.6% versus 70.5%, at 85 mcg/month versus 50 mcg/month. Hemoglobin did not differ significantly between groups, meaning the amlodipine group needed substantially more iron and erythropoiesis-stimulating therapy to reach the same hemoglobin target. (2) Prospective observational study, 128 heart-failure patients with iron deficiency, 36 (28.1%) on amlodipine: amlodipine use was associated with significantly lower serum iron (p=0.038), hemoglobin (p=0.018), and hematocrit (p=0.003), with an inverse correlation between amlodipine use and both hematocrit and iron.

Mechanism

Three mechanisms proposed by the authors, none directly tested against the others in either paper: reduced duodenal DMT-1 (divalent metal transporter-1) expression lowering dietary non-heme iron absorption (mechanism class A, absorption interference); blunted erythropoietin-stimulated erythropoiesis, since red-cell precursor proliferation partly depends on the same calcium influx amlodipine blocks (increased functional demand on the same iron pool); and a class-level association between calcium channel blockers and increased gastrointestinal bleeding risk cited from a separate meta-analysis, which would increase iron loss.

Counter-evidence held on record

Both supporting studies are observational, not randomized, so confounding by indication is presumed and not excluded: amlodipine is disproportionately used in patients with more resistant hypertension, more edema, or more comorbidity, any of which could independently associate with anemia or iron deficiency in CKD and HF populations. Neither study excludes the possibility that sicker patients were simply more likely to be prescribed both amlodipine and higher iron/ESA doses. The thalassemia RCT is the strongest-design amlodipine-specific iron study located and shows no effect on serum ferritin or liver iron, the two most standard systemic iron-status markers, demonstrating that amlodipine's iron-channel effect is tissue-restricted rather than systemic. This is not evidence that amlodipine causes iron deficiency in a general, otherwise-healthy user. The signal is confined to two disease populations (dialysis-dependent kidney failure and heart failure with pre-existing iron deficiency) where confounding by the underlying disease is a live, unexcluded explanation. It should not be generalized to "amlodipine depletes iron," and no supplement dose is recommended here; anyone in these specific populations with unexplained anemia or rising iron/ESA requirements should discuss it with their nephrologist or cardiologist.

Limits on what this shows

• Why no grade: Under this protocol, UNGRADED applies when there is neither Tier B mechanistic nor Tier C class-extrapolation evidence to support even a yellow grade, and no circulating consumer claim to rebut as white. Both conditions are met here: the one located human data point is confounded by two co-administered drugs and points in the opposite direction from a depletion claim, so it supports neither a yellow theoretical-depletion grade nor a white rebuttal of one; a direct drug-supplement interaction reference (HelloPharmacist) was checked and explicitly reports no known copper-amlodipine interaction, confirming no claim exists in circulation to rebut. This is printed as a gap, not as reassurance: the absence of a claim and the absence of drug-specific data are not evidence that amlodipine has no effect on copper, only that the question has not been studied.
• What would fill it: An amlodipine-monotherapy arm (not combined with an ARB or thiazide) with serum copper and ceruloplasmin measured before and after treatment initiation, or an in vitro/animal study testing amlodipine specifically against a copper-dependent enzyme or transporter (for example ceruloplasmin, cytochrome c oxidase, or the copper transporters ATP7A/ATP7B).

Regulatory status

Not addressed by the FDA label. Copper is not mentioned.

Population evidence

One study was located that reports copper status alongside amlodipine use: a three-year longitudinal study of 115 (92 completing) geriatric hypertensive patients on a fixed triple combination of amlodipine, valsartan, and hydrochlorothiazide (10/320/25 mg daily) found serum copper rose from 8.2 to 12.3 micromol/L (p<0.01) over three years. Amlodipine was never given or measured alone in this study, so its individual contribution, if any, cannot be isolated from valsartan or hydrochlorothiazide, and the direction found (an increase) does not support a depletion claim in any case.

Limits on what this shows

• Key negative or null findings: Two additional amlodipine-and-microbiome studies were located by title, one reporting S-amlodipine caused liver inflammation via intestinal microbiome alteration in rats, and one reporting amlodipine alleviates non-alcoholic fatty liver disease by modulating gut microbiota in a different rodent model, an opposite direction from the first. This review could not open either paper's full text after repeated attempts (automated access blocks across the publisher site and mirrors), so no statistic from either is cited; their titles alone show the amlodipine-and-microbiome literature does not agree on direction, which argues for caution rather than for a confident depletion or protection claim.
• At-risk subgroups: None established in humans. Confounding by indication is a live concern for any human amlodipine-and-microbiome comparison: hypertension itself is independently associated with gut dysbiosis in the literature, so a microbiome difference in treated hypertensive patients cannot be attributed to the drug without an untreated-hypertensive comparison arm, which none of the located studies provide.

Regulatory status

The FDA label lists gastrointestinal effects (including abdominal pain and, less commonly, altered bowel habits) among amlodipine's recognized adverse reactions; it does not address the gut microbiome.

Population evidence

18 male Sprague-Dawley rats, three groups of six (saline control, amlodipine alone, amlodipine plus a probiotic blend), oral gavage for approximately four weeks. Amlodipine produced GI complications described as constipation and inflammation, elevated serum corticosterone (HPA-axis activation), and a distinct serum lipid metabolome (higher phosphatidylcholines, lysophosphatidylcholines, sphingomyelins, and cholesterol esters; lower polyunsaturated triglycerides) compared to control. The co-administered probiotic blend normalized the lipid profile and reduced the GI and corticosterone changes, which the authors used to argue that amlodipine-induced gut-microbiome change is a causal step in the drug's own GI and inflammatory side effects, not an incidental finding.

Mechanism

Not fully characterized. The authors' own framing treats this as downstream of amlodipine's known GI motility effect (dihydropyridine calcium-channel blockade relaxes intestinal smooth muscle, slowing transit; mechanism class A, altered transit time), with the resulting change in gut transit time plausibly reshaping the microbial community, which the paper then links to systemic lipid and inflammatory changes. This is presented as explaining a recognized amlodipine side effect via the microbiome, not as a new nutrient-depletion pathway.

Counter-evidence held on record

No human, amlodipine-specific gut-microbiome study was located at any tier. The rat literature itself is directionally inconsistent across the three studies found (one showing GI harm linked to microbiome change, one showing liver inflammation via microbiome change, one showing a beneficial NAFLD effect via microbiome change), which is itself evidence against treating any single rat finding as a settled mechanism. This is not a nutrient-deficiency finding. Amlodipine's recognized GI side effects (constipation-type symptoms in a minority of users) are a known clinical effect of the drug's smooth-muscle relaxation, not evidence of an endogenous-synthesis nutrient loss, and no probiotic or supplement dose is recommended here.

Limits on what this shows

• Key negative or null findings: No study located measured whole-body oxygen utilization (VO2, exercise capacity, tissue hypoxia markers) in amlodipine users in a way that isolated a nutrient-mediated mechanism from the drug's known hemodynamic effects; amlodipine is well documented to improve, not worsen, exertional capacity in angina populations via its vasodilatory action, which further argues against a distinct oxygen-utilization depletion mechanism.
• At-risk subgroups: Same as the Iron entry: heart-failure patients with pre-existing iron deficiency. No subgroup is defined for a delivery-side (blood-flow) risk, because the located evidence for that side of the mechanism is entirely in the beneficial direction.

Regulatory status

Amlodipine's vasodilatory action is its labeled mechanism of action for treating hypertension and angina; the label does not address tissue oxygenation or oxygen-carrying capacity as a safety parameter.

Population evidence

An animal study (title and existence confirmed via indexing; full text could not be opened, so no statistic is cited here) reports amlodipine increasing coronary blood flow through adenosine- and nitric-oxide-dependent mechanisms in ischemic hearts, consistent with amlodipine's established vasodilatory and anti-anginal action. Separately, the heart-failure cohort already discussed under the Iron entry (n=128, 36 on amlodipine) found significantly lower hemoglobin (p=0.018) and hematocrit (p=0.003) in amlodipine users, which is a blood oxygen-carrying-capacity finding, not a delivery (blood flow) finding.

Mechanism

Two mechanisms operate in opposite senses and must not be merged: (1) improved regional blood flow via L-type calcium-channel blockade in vascular smooth muscle, amlodipine's own intended pharmacological action, which is a delivery-side effect and not a nutrient mechanism under this protocol's hard rules; (2) lower hemoglobin/hematocrit correlating with amlodipine use in iron-deficient heart-failure patients, a carriage-side effect that is the same finding already graded and counted under Iron, not a separate mechanism.

Counter-evidence held on record

Amlodipine's vasodilatory, blood-flow-improving action is well established and consistently in the beneficial direction; it is excluded from grading here as a known pharmacological effect, not a nutrient finding, per this protocol's rule against filing a drug's intended action as a deficiency mechanism. Do not present amlodipine as improving "oxygen levels" in a nutrient or wellness sense. Where a real carriage-side signal exists, it is the hemoglobin/hematocrit finding already presented under Iron; this entry exists to state plainly that no separate oxygen-delivery depletion mechanism was found, and to keep the vasodilation mechanism from being mistaken for one.

Limits on what this shows

• Key negative or null findings: No study reviewed found amlodipine lowering ATP production in any tissue or model, injured or otherwise. No case reports of exertional fatigue or exercise intolerance specifically attributed to an amlodipine-induced energy-production defect were located; amlodipine's well-documented fatigue and dizziness adverse effects in its label are attributed to blood-pressure lowering and vasodilation, not to impaired ATP synthesis, and must not be relabeled as such.
• At-risk subgroups: None identified. The single supporting data point is from an induced-ischemia cell model, not a baseline human physiological measurement.

Regulatory status

Not addressed by the FDA label; cellular ATP production is not a monitored parameter.

Population evidence

Same in vitro neural-stem-cell, oxygen-glucose-deprivation study cited under Mitochondrial burden above (five independent experiments per assay): ATP concentration, measured by luminescence assay, was markedly higher in amlodipine-camsylate-treated, injured cells than in injured cells without amlodipine.

Mechanism

Same calcium-channel mechanism as the mitochondrial-burden entry: reduced calcium influx prevents mitochondrial permeability transition pore opening, which under injury conditions preserves the mitochondrial membrane potential that drives ATP synthesis. This is reported here as the specific ATP-concentration endpoint from that study, distinct from the ultrastructure and reactive-oxygen-species endpoints reported under Mitochondrial burden; both entries draw on the same paper because it measured multiple distinct outcomes, not because the same statistic is being counted twice.

Counter-evidence held on record

The evidence base for this entry is one in vitro paper in a non-cardiovascular, non-muscle cell type (neural stem cells) under an injury condition that does not represent ordinary use. It is included because it is the only amlodipine-specific ATP measurement located, not because it is strong or generalizable evidence. This must not be presented as amlodipine increasing energy or ATP in a wellness sense for a typical user. It is a single injury-model finding explained by calcium-channel pharmacology, and it carries no dosing or supplement implication.