Fentanyl

Limits on what this shows

• Key negative or null findings: Lamprecht 2018 [11] (40 opioid users with oral or transdermal opioids versus 25 controls): male testosterone was inversely correlated with BMI (P=0.001) but not with opioid exposure. Fentanyl is not named in the abstract, so hydrocodone-versus-fentanyl detail cannot be confirmed there (Tier C for this drug; CLASS EXTRAPOLATION). A 2025 narrative review of opioid-induced androgen deficiency [12] gives prevalence of 20 to 80% depending on drug, duration, age and criteria; fentanyl is not named in the abstract (Tier C).
• At-risk subgroups: Men on continuous long-term single-opioid therapy; the cohort excluded cancer pain. Women and premenopausal effects were not assessed in [8]. Two Daniell papers on sustained-action opioids in women and on DHEAS [13][14] were seen as OpenAlex metadata only (abstracts null) and are not used for any claim.
• Counter-evidence and confounders: The comparator is another opioid, not non-use: hydrocodone itself suppresses testosterone dose-dependently in [8], so the odds ratio measures fentanyl against an active drug and does not give the absolute risk. Chronic pain, obesity, age and co-medication lower testosterone independently. Wide interval: the lower bound of 2.82 is the only firm statement.

Regulatory status

Duragesic label section 6.2: "Cases of androgen deficiency have occurred with chronic use of opioids" [1]. Fentanyl citrate injection label section 12.2: opioids inhibit secretion of ACTH, cortisol and luteinizing hormone, and "use of opioids for an extended period may influence the hypothalamic-pituitary-gonadal axis, leading to androgen deficiency" [2]. Both read through a summarizing fetch tool.

Population evidence, this drug in cohort

Rubinstein and Carpenter [8]: retrospective cohort in a large integrated health system, 1,159 men aged 18 to 80 on a stable single opioid for non-cancer pain for at least 90 days; morning total testosterone; logistic regression adjusted for dose, obesity, age, hypertension, hyperlipidemia and diabetes; hydrocodone was the referent. Fentanyl OR 25.7 (95% CI 2.82 to 234.97), methadone OR 7.33 (3.29 to 16.33), oxycodone OR 3.15 (1.87 to 5.33). The abstract (reconstructed from OpenAlex, read through a summarizing fetch tool) concludes that transdermal fentanyl and methadone carried the highest risk. The number of fentanyl users was not in the text read; the interval width implies a small group. Fentanyl is in the cohort (Tier A for the hormone outcome); the nutrient question is not addressed because the outcome is a hormone.

Mechanism

Named in the labels: opioid inhibition of LH and the hypothalamic-pituitary-gonadal axis with extended use [2]. No fentanyl-specific hormone assay study beyond [8] was opened.

Boundary stated for the orange grade

Men, stable single-opioid regimens of at least 90 days, hydrocodone-referent odds ratio, one cohort, fentanyl subgroup size unknown. A second independent cohort naming fentanyl would be needed to approach red, and the outcome would remain a hormone rather than a nutrient.

Counter-evidence held on record

Framing caution for the consumer surface This is a hormone effect of long-term opioid therapy that may occur with this drug. It is not a nutrient deficiency, and no vitamin, mineral or testosterone supplement is indicated by this entry. Testing and treatment belong with a clinician.

Limits on what this shows

• Key negative or null findings: The review [10] notes it is not known whether adrenal insufficiency is more or less associated with specific opioids or routes; the label says the same [1]. No fentanyl cohort measuring cortisol was opened.
• At-risk subgroups: Patients on more than one month of continuous therapy (label wording [1]). Symptoms listed in the label are non-specific: nausea, vomiting, anorexia, fatigue, weakness, dizziness and low blood pressure.
• Counter-evidence and confounders: Underlying illness, glucocorticoid co-treatment, and the single-patient nature of the fentanyl report.

Regulatory status

Duragesic label section 5.12: "Cases of adrenal insufficiency have been reported with opioid use, more often following greater than one month of use"; management is physiologic corticosteroid replacement with opioid weaning, and "The information available does not identify any particular opioids as being more likely to be associated with adrenal insufficiency" [1]. Read through a summarizing fetch tool.

Population evidence, this drug in cohort

Int J Mol Sci 2023 narrative review [10] (opened): reports a 46-year-old woman treated for non-cancer pain for four years with a transdermal fentanyl patch (90 to 120 morphine milligram equivalents per day) who developed fatigue, reduced energy and loss of appetite in the second year and was diagnosed with opioid-induced adrenal insufficiency by laboratory testing. This is a case report cited as reference 37 of the review; the original report could not be identified because the review reference list was truncated in the fetch, so it is Tier B at second hand. Not a cohort.

CLASS EXTRAPOLATION: cohort test

Lamprecht 2018 [11]: 40 opioid users on oral or transdermal opioids versus 25 controls; secondary adrenal insufficiency in 22.5% versus 0% (P=0.01), more often with higher morphine-equivalent dose (P=0.037). Fentanyl is NOT named in the abstract, although transdermal opioids appear in the title: Tier C for this drug, held at yellow. The review [10] reports 9.2% HPA suppression among intrathecal morphine or hydromorphone users: fentanyl not in that cohort.

Mechanism

Named in the injection label section 12.2: opioids inhibit ACTH and cortisol secretion [2].

Counter-evidence held on record

Framing caution for the consumer surface A hormone-axis monitoring point, not a nutrient finding. Fatigue and low appetite are non-specific and should be evaluated by a clinician. No supplement is implied.

Limits on what this shows

• Key negative or null findings: None located; no sodium measurement in fentanyl users was found.
• At-risk subgroups: Patients on diuretics (label interaction) are the only subgroup the label names [1]. Others are inferred, not documented, for fentanyl.
• Counter-evidence and confounders: Surgery, heart or liver disease, thiazides, SSRIs and fluid replacement all alter sodium independently.

Regulatory status

Duragesic label section 7: "Opioids can reduce the efficacy of diuretics by inducing the release of antidiuretic hormone" [1]; the same sentence is in the injection label table of interactions [2]. No hyponatremia or SIADH wording was found in the text of either label or of the SpecGx patch label as returned by the summarizer [1][2][3]. Absence from a summary is not proof of absence.

Population evidence, this drug in cohort

None opened. Searches of PubMed, Europe PMC, OpenAlex and Crossref for fentanyl with hyponatremia or SIADH were rate-limited (429) and could not be run; the web search budget was also exhausted. The only evidence is the label mechanism statement (Tier B, established pharmacology). The tramadol hyponatremia cohort literature is a different, serotonergic mechanism and was not used.

Mechanism

Named in the label: opioid-induced ADH release [1][2].

Counter-evidence held on record

Framing caution for the consumer surface Retention or dilution risk, not a deficiency. Supplemental sodium or salt loading would be the hazard. Any sodium concern is a clinician decision.

Limits on what this shows

• Key negative or null findings: No 25(OH)D measurement in fentanyl users was found; database searches were rate-limited.
• Counter-evidence and confounders: Confounding by indication is presumed (Hard Rule 6): chronic pain, immobility and obesity are linked to low vitamin D independent of any drug, and no before-and-after data exist.

Regulatory status

No vitamin D wording in the label text read [1][2][3].

CLASS EXTRAPOLATION: cohort test

Frontiers in Nutrition 2024 [15] (opened): NHANES 2001 to 2018, 1,856 long-term (at least 90 days) prescription opioid users, defined as use of narcotic analgesics; 67.2% had insufficient 25(OH)D (below 75 nmol/L). The text names no individual opioid (methadone, naloxone and buprenorphine users were excluded), so fentanyl is NOT confirmed in the cohort: Tier C. No opioid-free comparison group was in the findings read, so the 67.2% cannot be attributed to any drug.

Direction check (Hard Rule 4)

The papers that connect vitamin D and opioids run from vitamin D to opioid response. Kemeny 2021 [16] (abstract read via OpenAlex): low vitamin D signaling amplified opioid responses in mice, and vitamin D insufficiency was more prevalent in opioid use disorder; fentanyl is not named. A Mayo Clinic news release on a 2010 chronic pain study [17] says narcotic drugs "such as morphine, fentanyl or oxycodone" were taken by these patients and that those with insufficient vitamin D needed about double the narcotic dose; the underlying study was not opened, and the direction is vitamin D status affecting opioid need.

Mechanism

Absent for fentanyl. No absorption, catabolism or renal mechanism was found. Indirect routes (hypogonadism, reduced mobility and sun exposure) are condition-linked.

Counter-evidence held on record

Framing caution for the consumer surface High vitamin D insufficiency in the opioid-treated population is not evidence that fentanyl causes it. Any testing decision belongs in the monitoring panel and with a clinician.

Limits on what this shows

• Key negative or null findings: Active-comparator trials do not test fentanyl against non-use; the lower rate is relative to oral morphine only.
• At-risk subgroups: Not defined in the text read; reduced mobility and low fluid intake are general contributors.
• Counter-evidence and confounders: Cancer, diet, dehydration, immobility and co-medication drive constipation independently.

Regulatory status

Duragesic label: constipation is among the most common adverse reactions (5% or more), 9% on DURAGESIC versus 1% on placebo in the section 6.1 table as returned by the summarizer, with nausea 41% and vomiting 26% [1]; contraindicated in known or suspected gastrointestinal obstruction including paralytic ileus (5.18) [1]. Injection label section 12.2: fentanyl reduces motility with increased smooth muscle tone, and propulsive peristaltic waves in the colon are decreased [2].

Population evidence, this drug in cohort

Cochrane review of transdermal fentanyl for cancer pain, Hadley 2013 [9] (abstract reconstructed from OpenAlex): 9 randomized trials, 1,244 participants in classical designs (1,197 evaluable) plus 138 in enriched-enrolment trials, comparators including oral morphine formulations, methadone and paracetamol-codeine. Constipation 28% with transdermal fentanyl versus 46% with oral morphine, RR 0.61 (95% CI 0.47 to 0.78), number needed to treat 5.5. Tier A for the clinical outcome, fentanyl in cohort, but the outcome is not a nutrient.

Mechanism

Named: mu-opioid receptor reduction of gut motility [2].

Counter-evidence held on record

Framing caution for the consumer surface A bowel effect to manage with the prescriber, not a sign of a nutrient shortage. No fiber, magnesium or other supplement recommendation is made.

Limits on what this shows

• Key negative or null findings: No fentanyl-specific grapefruit pharmacokinetic study was opened, and the transdermal route partly bypasses first-pass metabolism, so the magnitude for patches is not documented in the text read.
• At-risk subgroups: Patients also taking azole antifungals, macrolides or protease inhibitors, per the label [1].
• Counter-evidence and confounders: None; the label statement is class-wide for CYP3A4 inhibitors.

Regulatory status

Duragesic label section 7, Table 6, CYP3A4 inhibitor examples as returned by the summarizer: macrolide antibiotics, azole antifungals, protease inhibitors and "grapefruit juice"; "concomitant use of DURAGESIC and CYP3A4 inducers can decrease the plasma concentration of fentanyl"; discontinuing a CYP3A4 inducer may raise fentanyl concentration (5.6) [1]. Injection label 5.4: CYP3A4 inhibitors may increase and inducers may lower fentanyl concentrations [2]. St. John's wort was not found in the Duragesic text read [1].

Population evidence, this drug in cohort

A consumer drug-interaction page [34] (Tier D, not used to support the grade) lists alcohol (additive CNS depression) and grapefruit (CYP3A4 inhibition) as the only food interactions. StatPearls [6] states fentanyl is hepatically metabolized via CYP3A4.

Mechanism

Named: CYP3A4 inhibition raising fentanyl exposure [1][6].

Counter-evidence held on record

Framing caution for the consumer surface This is not a deficiency. Whether to avoid grapefruit juice is a prescriber or pharmacist decision. No timing interval is established in the text read, and no supplement is implied.

Why no ungraded entry

The dual condition in Step 7 (no Tier B or C evidence and no circulating claim) was not met for any entry. The weakest yellow entries are sodium (label mechanism only), oxygen delivery (label pharmacology only) and the six class extrapolations (vitamin D, microbiome, oxidative stress, ATP, copper, iron), where no fentanyl-specific data were opened.

Channels tried

Drugs.com label mirrors for Duragesic, fentanyl citrate injection and Fentora (opened at several offsets); DailyMed SPL index listing (one call worked), DailyMed label pages for the SpecGx patch (opened; sections 12.2 and 12.3 not returned); WHO ATC page; StatPearls; single-record OpenAlex lookups by PMID or DOI (worked for about 20 records); De Gruyter, Nature, Frontiers, MDPI, Springer, eNeuro, a university repository PDF and a journal abstract page (worked); PubMed listing and record pages (429, not retried), Europe PMC (429), OpenAlex search endpoints (429), Crossref title and DOI queries (one returned unrelated records, others 429), Semantic Scholar (429); journal search pages at Springer, MDPI and PLOS were disallowed by robots rules and not circumvented; WebSearch reported its shared budget exhausted; DailyMed original Duragesic search returned zero results.

Gap type

Tooling-limited for fentanyl-specific microbiome, oxidative stress, hyponatremia, vitamin D, iron and hemoglobin searches; these should be re-run when PubMed and Europe PMC are reachable. Genuine literature gaps were not established.