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Midazolam Hydrochloride side effects: what 26,764 FDA adverse event reports show

Midazolam Hydrochloride · Nayzilam · 1,202 reaction terms · 102,037 drug–reaction co-reports · data 2026-09-14
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Drug class

Benzodiazepine

FDA label (Established Pharmacologic Class) · compare the class

Brand names

Nayzilam

openFDA label

Who reports

26,764 reports · 93% serious · 5,139 with death outcome · 48% female

openFDA FAERS counts, all years, deduplication not applied

Used for

NAYZILAM is indicated for the acute treatment of intermittent, stereotypic episodes of frequent seizure activity (i.e., seizure clusters, acute repetitive seizures) that are distinct from a patient's usual seizure pattern in patients with epilepsy 12 years of age and older.

FDA label, Indications and Usage

What it is

NAYZILAM contains midazolam, a compound of the benzodiazepine class. Midazolam is chemically designated as 8-Chloro-6-(ο-fluorophenyl)-1-methyl-4H-imidazo[1,5-a][1,4]benzodiazepine, and it has the following structure:

FDA label, Description section

Boxed warning

RISKS FROM CONCOMITANT USE WITH OPIOIDS; ABUSE, MISUSE, AND ADDICTION; and DEPENDENCE AND WITHDRAWAL REACTIONS Concomitant use of benzodiazepines and opioids may result in profound sedation, respiratory depression, coma, and death . Reserve concomitant prescribing of these drugs for patients for whom alternative treatment options are inadequate.

FDA label
How to read this page. FAERS is a spontaneous-reporting system: counts are not incidence rates and a signal is not proof of causation. Each reaction below is run through an automated screen — is the term in the FDA label (known), in the indications (the disease being treated), an administrative/coding term, or none of these (unlabeled)? That screen is mechanical text matching, not a causality assessment. The 30 hand-written Bradford Hill assessments are on the causality assessment page. Not medical advice.

Causality screen of the 40 strongest signals

Labeled (related wording) 3Likely indication confounding 2Reporting / coding artifact 1Lab value / disease marker 6Not in label — unassessed 28
What the badges mean

Strongest disproportionality signals

Flagged terms (PRR ≥ 2, χ² ≥ 4, n ≥ 10), ranked by PRR; infinite PRRs (no comparator reports) excluded. The EBGM column is a second, shrinkage-based estimate (MGPS) with its 5th percentile EB05 and the BCPNN IC025; a pair flagged by PRR alone is marked PRR-only and should be read as fragile. The strata column recomputes the PRR on serious reports only (and, for the 300 most-reported drugs, adjusted for age band), and flags pairs whose reports are unusually skewed by sex or come mostly from consumers. Each row also shows the PRR against the other drugs of the same FDA class, which removes most confounding by the condition being treated, and a calibrated p-value: on validation, known non-causes average an ROR of about 2, so significance is judged against that empirical null (✓ = p < 0.05 after calibration). 1,162 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.

Show:
ReactionReportsPRR 95% CI · ROR · χ²/pEBGM EB05 · IC025Label screenSerious-only & strataTrial cross-check
Vaginal flatulence1751,063.9
846.8–1,336.5ROR 1,070.9 · calibrated p 3e-17 ✓
427.0 EB05 376.5 · IC025 +7.4
3/3 methods agree
vs other Benzodiazepines: PRR 247.8 (209.7–292.8)
Not in label — unassessedserious n=175 · ♀ 100% (drug 48%)no trial data cached
Mitochondrial dna mutation38624.2
407.1–957.1ROR 625.1 · calibrated p 7e-14 ✓
294.4 EB05 223.9 · IC025 +5.4
3/3 methods agree
vs other Benzodiazepines: PRR 243.7 (165.5–358.8)
Not in label — unassessedserious n=38 · ♀ 100% (drug 48%)no trial data cached
New onset refractory status epilepticus40475.1
320.5–704.3ROR 475.8 · calibrated p 7e-13 ✓
258.2 EB05 197.8 · IC025 +5.5
3/3 methods agree
vs other Benzodiazepines: PRR 315.0 (211.9–468.3)
Likely indication confounding
shares a disease stem with the indications wording
serious n=40 · ♀ 0% (drug 48%) · 100% clinicianno trial data cached
Trigemino-cardiac reflex27386.0
243.3–612.6ROR 386.4 · calibrated p 9e-12 ✓
218.1 EB05 157.4 · IC025 +4.9
3/3 methods agree
vs other Benzodiazepines: PRR 448.9 (264.9–760.7)
Not in label — unassessedserious n=27 · ♀ 0% (drug 48%) · 100% clinicianno trial data cached
Chest wall rigidity20350.9
206.9–595.3ROR 351.2 · calibrated p 4e-11 ✓
196.5 EB05 134.3 · IC025 +4.4
3/3 methods agree
vs other Benzodiazepines: PRR 498.7 (265.1–938.2)
Not in label — unassessedserious n=20 · 100% clinicianno trial data cached
Myoglobin urine present62258.7
194.1–344.9ROR 259.3 · calibrated p 9e-11 ✓
183.2 EB05 148.0 · IC025 +5.8
3/3 methods agree
vs other Benzodiazepines: PRR 299.2 (219.2–408.6)
Lab value / disease markerserious n=61 · ♀ 100% (drug 48%) · 95% clinicianno trial data cached
Intra-abdominal pressure increased35225.2
154.6–328.1ROR 225.5 · calibrated p 5e-10 ✓
159.5 EB05 119.9 · IC025 +5.1
3/3 methods agree
vs other Benzodiazepines: PRR 604.3 (366.0–997.5)
Lab value / disease markerserious n=35 · ♀ 100% (drug 48%)no trial data cached
Propofol infusion syndrome156222.6
186.4–265.9ROR 223.9 · calibrated p 2e-10 ✓
169.5 EB05 148.3 · IC025 +6.5
3/3 methods agree
vs other Benzodiazepines: PRR 355.5 (292.6–431.8)
Not in label — unassessedserious n=156 · 95% clinicianno trial data cached
Csf oligoclonal band present25201.1
129.5–312.2ROR 201.2 · calibrated p 2e-9 ✓
142.6 EB05 101.5 · IC025 +4.6
3/3 methods agree
vs other Benzodiazepines: PRR 244.0 (150.9–394.5)
Lab value / disease markerserious n=25 · ♀ 100% (drug 48%)no trial data cached
Burkholderia test positive23177.6
112.9–279.4ROR 177.7 · calibrated p 6e-9 ✓
129.3 EB05 90.7 · IC025 +4.5
3/3 methods agree
vs other Benzodiazepines: PRR 516.2 (285.0–935.0)
Lab value / disease markerserious n=23 · 100% clinicianno trial data cached
Intensive care unit acquired weakness61149.0
113.3–196.0ROR 149.4 · calibrated p 9e-9 ✓
120.4 EB05 97.1 · IC025 +5.5
3/3 methods agree
vs other Benzodiazepines: PRR 355.6 (256.5–492.9)
Not in label — unassessedserious n=61 · 100% clinicianno trial data cached
Anal prolapse19148.2
90.7–242.1ROR 148.3 · calibrated p 3e-8 ✓
110.9 EB05 75.0 · IC025 +4.1
3/3 methods agree
vs other Benzodiazepines: PRR 448.9 (238.8–843.6)
Not in label — unassessedserious n=19no trial data cached
Airway peak pressure increased23139.8
89.7–218.0ROR 139.9 · calibrated p 4e-8 ✓
108.1 EB05 75.9 · IC025 +4.4
3/3 methods agree
vs other Benzodiazepines: PRR 573.6 (311.1–1,057.4)
Lab value / disease markerserious n=23 · 100% clinicianno trial data cached
Necrosis ischaemic60116.7
89.0–153.0ROR 116.9 · calibrated p 6e-8 ✓
98.4 EB05 79.2 · IC025 +5.4
3/3 methods agree
vs other Benzodiazepines: PRR 598.5 (410.0–873.7)
Not in label — unassessedserious n=60no trial data cached
Unwanted awareness during anaesthesia39105.7
75.6–147.6ROR 105.8 · calibrated p 2e-7 ✓
89.1 EB05 68.0 · IC025 +4.9
3/3 methods agree
vs other Benzodiazepines: PRR 473.1 (303.9–736.7)
Not in label — unassessedserious n=35 · ♀ 100% (drug 48%) · 100% clinicianno trial data cached
Myocardial depression28103.4
69.7–153.4ROR 103.5 · calibrated p 2e-7 ✓
86.1 EB05 62.5 · IC025 +4.5
3/3 methods agree
vs other Benzodiazepines: PRR 196.4 (126.9–304.0)
Not in label — unassessedserious n=28 · ♀ 100% (drug 48%) · 100% clinicianno trial data cached
Neuromuscular block prolonged4299.8
72.4–137.6ROR 99.9 · calibrated p 2e-7 ✓
85.2 EB05 65.6 · IC025 +4.9
3/3 methods agree
vs other Benzodiazepines: PRR 523.7 (337.9–811.6)
Not in label — unassessedserious n=38 · 100% clinicianno trial data cached
Female genital tract fistula19097.2
83.6–113.0ROR 97.9 · calibrated p 2e-7 ✓
85.7 EB05 76.0 · IC025 +5.9
3/3 methods agree
vs other Benzodiazepines: PRR 241.6 (206.4–282.8)
Not in label — unassessedserious n=190 · ♀ 100% (drug 48%)no trial data cached
Anaesthetic complication neurological9591.1
73.7–112.7ROR 91.4 · calibrated p 3e-7 ✓
80.3 EB05 67.7 · IC025 +5.5
3/3 methods agree
vs other Benzodiazepines: PRR 453.7 (344.9–596.6)
Not in label — unassessedserious n=94 · 100% clinicianno trial data cached
Hepatic ischaemia3289.5
62.1–129.1ROR 89.6 · calibrated p 6e-7 ✓
76.8 EB05 56.9 · IC025 +4.6
3/3 methods agree
vs other Benzodiazepines: PRR 495.3 (301.6–813.6)
Not in label — unassessedserious n=32 · ♀ 100% (drug 48%) · 100% clinicianno trial data cached
Postoperative delirium1987.8
54.7–141.2ROR 87.9 · calibrated p 1e-6 ✓
73.4 EB05 49.6 · IC025 +3.9
3/3 methods agree
vs other Benzodiazepines: PRR 501.7 (262.0–960.6)
Not in label — unassessedserious n=19no trial data cached
Multiple-drug resistance30385.0
75.6–95.7ROR 86.0 · calibrated p 4e-7 ✓
76.3 EB05 69.4 · IC025 +5.9
3/3 methods agree
vs other Benzodiazepines: PRR 84.2 (76.6–92.4)
Reporting / coding artifactserious n=238 · 98% clinicianno trial data cached
Hyperthermia malignant13880.7
67.8–96.1ROR 81.1 · calibrated p 6e-7 ✓
72.5 EB05 62.9 · IC025 +5.6
3/3 methods agree
vs other Benzodiazepines: PRR 472.9 (377.4–592.5)
Not in label — unassessedserious n=135 · ♀ 20% (drug 48%) · 97% clinicianno trial data cached
Neuromuscular blockade2179.5
50.7–124.5ROR 79.5 · calibrated p 2e-6 ✓
67.9 EB05 46.8 · IC025 +4.0
3/3 methods agree
vs other Benzodiazepines: PRR 471.3 (256.8–865.0)
Not in label — unassessedserious n=19no trial data cached
Airway complication of anaesthesia2376.2
49.7–116.9ROR 76.3 · calibrated p 2e-6 ✓
65.8 EB05 46.2 · IC025 +4.1
3/3 methods agree
vs other Benzodiazepines: PRR 491.6 (273.5–883.6)
Not in label — unassessedserious n=22 · 100% clinicianno trial data cached
Delayed recovery from anaesthesia8274.1
59.1–93.0ROR 74.4 · calibrated p 1e-6 ✓
66.7 EB05 55.5 · IC025 +5.2
3/3 methods agree
vs other Benzodiazepines: PRR 557.7 (407.3–763.7)
Not in label — unassessedserious n=80 · 100% clinicianno trial data cached
Carcinoid crisis1763.1
38.5–103.4ROR 63.1 · calibrated p 1e-5 ✓
55.0 EB05 36.4 · IC025 +3.7
3/3 methods agree
vs other Benzodiazepines: PRR 448.9 (230.2–875.1)
Not in label — unassessedserious n=17no trial data cached
Pneumatosis3362.8
44.0–89.5ROR 62.8 · calibrated p 6e-6 ✓
56.3 EB05 42.0 · IC025 +4.4
3/3 methods agree
vs other Benzodiazepines: PRR 617.2 (367.0–1,038.0)
Not in label — unassessedserious n=33 · ♀ 100% (drug 48%)no trial data cached
Proctitis20461.4
53.3–70.8ROR 61.9 · calibrated p 4e-6 ✓
56.7 EB05 50.5 · IC025 +5.4
3/3 methods agree
vs other Benzodiazepines: PRR 248.8 (213.8–289.6)
Not in label — unassessedserious n=204 · ♀ 95% (drug 48%)no trial data cached
Radiculopathy18358.4
50.3–67.8ROR 58.8 · calibrated p 5e-6 ✓
54.1 EB05 47.8 · IC025 +5.3
3/3 methods agree
vs other Benzodiazepines: PRR 177.0 (152.1–206.0)
Not in label — unassessedserious n=183 · ♀ 100% (drug 48%)no trial data cached
Local anaesthetic systemic toxicity6552.4
40.8–67.3ROR 52.5 · calibrated p 1e-5 ✓
48.5 EB05 39.4 · IC025 +4.8
3/3 methods agree
vs other Benzodiazepines: PRR 463.1 (330.5–649.0)
Not in label — unassessedserious n=65 · 100% clinicianno trial data cached
Status epilepticus69351.1
47.3–55.1ROR 52.4 · calibrated p 1e-5 ✓
47.9 EB05 45.0 · IC025 +5.4
3/3 methods agree
vs other Benzodiazepines: PRR 83.2 (81.7–84.6)
Likely indication confounding
shares a disease stem with the indications wording
serious PRR 29.6 · 95% clinicianno trial data cached
Diabetes insipidus14750.6
42.8–59.8ROR 50.9 · calibrated p 1e-5 ✓
47.3 EB05 41.2 · IC025 +5.1
3/3 methods agree
vs other Benzodiazepines: PRR 360.6 (294.6–441.4)
Not in label — unassessedserious n=147 · 92% clinicianno trial data cached
Renal ischaemia3249.0
34.3–70.1ROR 49.1 · calibrated p 3e-5 ✓
45.0 EB05 33.4 · IC025 +4.2
3/3 methods agree
vs other Benzodiazepines: PRR 798.0 (450.4–1,413.9)
Not in label — unassessedserious n=32 · ♀ 100% (drug 48%)no trial data cached
Pseudopolyp2148.5
31.2–75.4ROR 48.6 · calibrated p 4e-5 ✓
44.0 EB05 30.4 · IC025 +3.8
3/3 methods agree
vs other Benzodiazepines: only this drug
Not in label — unassessedserious n=21no trial data cached
Po2 increased2845.3
31.0–66.3ROR 45.4 · calibrated p 5e-5 ✓
41.7 EB05 30.3 · IC025 +4.0
3/3 methods agree
vs other Benzodiazepines: PRR 698.2 (388.3–1,255.6)
Not in label — unassessedserious n=27 · ♀ 100% (drug 48%)no trial data cached
Blood gases abnormal2944.9
30.9–65.2ROR 44.9 · calibrated p 5e-5 ✓
41.4 EB05 30.2 · IC025 +4.0
3/3 methods agree
vs other Benzodiazepines: PRR 241.1 (154.6–375.9)
Lab value / disease markerserious n=28 · ♀ 100% (drug 48%)no trial data cached

Trial evidence (ClinicalTrials.gov)

Trial cross-check not yet run for this drug (ClinicalTrials.gov pull covers the 800 most-reported drugs first).

Most frequently reported reactions

By raw co-report count, regardless of disproportionality. Common terms here are often the illness itself or generic outcomes.

ReactionReportsPRR 95% CI · ROR · χ²/pEBGM EB05 · IC025Label screenSerious-only & strataTrial cross-check
Drug ineffective (drug did not work)3,4052.0
2.0–2.1ROR 2.2 · calibrated p 0.962
2.0 EB05 2.0 · IC025 +1.0
vs other Benzodiazepines: PRR 24.7 (24.7–24.7)
Reporting / coding artifactserious PRR 3.2 · 92% clinicianno trial data cached
Off label use (used outside approved label)2,5572.3
2.2–2.4ROR 2.5 · calibrated p 0.834
2.3 EB05 2.2 · IC025 +1.1
3/3 methods agree
vs other Benzodiazepines: PRR 27.8 (27.8–27.8)
Reporting / coding artifactserious PRR 2.4no trial data cached
Hypotension (low blood pressure)1,5756.2
5.9–6.5ROR 6.5 · calibrated p 0.120
6.2 EB05 5.9 · IC025 +2.5
3/3 methods agree
vs other Benzodiazepines: PRR 35.7 (35.7–35.7)
Labeled adverse reaction
exact term
serious PRR 4.4 · 93% clinicianno trial data cached
Drug interaction1,2476.2
5.9–6.5ROR 6.5 · calibrated p 0.124
6.1 EB05 5.9 · IC025 +2.5
3/3 methods agree
vs other Benzodiazepines: PRR 21.5 (21.5–21.5)
Reporting / coding artifactserious PRR 4.1 · 94% clinicianno trial data cached
Seizure1,1988.3
7.8–8.7ROR 8.6 · calibrated p 0.053
8.2 EB05 7.8 · IC025 +2.9
3/3 methods agree
vs other Benzodiazepines: PRR 27.6 (27.6–27.6)
Likely indication confounding
term in indications; also in warnings
serious PRR 5.2no trial data cached
Pyrexia (fever)9602.2
2.0–2.3ROR 2.2 · calibrated p 0.942
2.2 EB05 2.1 · IC025 +1.0
3/3 methods agree
vs other Benzodiazepines: PRR 19.4 (19.4–19.4)
Not in label — unassessedserious PRR 1.7no trial data cached
Toxicity to various agents9374.4
4.1–4.7ROR 4.5 · calibrated p 0.295
4.4 EB05 4.1 · IC025 +2.0
3/3 methods agree
vs other Benzodiazepines: PRR 9.6 (9.6–9.6)
Not in label — unassessedserious PRR 2.8 · 95% clinicianno trial data cached
Cardiac arrest (heart stopping)9378.9
8.4–9.5ROR 9.2 · calibrated p 0.042 ✓
8.8 EB05 8.4 · IC025 +3.0
3/3 methods agree
vs other Benzodiazepines: PRR 32.9 (32.9–32.9)
Labeled adverse reaction
exact term
serious PRR 5.5 · 90% clinicianno trial data cached
Acute kidney injury (sudden kidney damage)9284.8
4.5–5.1ROR 4.9 · calibrated p 0.242
4.8 EB05 4.5 · IC025 +2.1
3/3 methods agree
vs other Benzodiazepines: PRR 29.5 (29.5–29.5)
Not in label — unassessedserious PRR 2.9 · 95% clinicianno trial data cached
Death7330.7
0.6–0.7ROR 0.7 · calibrated p 0.110
0.7 EB05 0.6 · IC025 -0.7
PRR-only: not supported by EBGM or IC
vs other Benzodiazepines: PRR 11.3 (11.3–11.3)
Outcome field, not a reaction
boxed warning mentions mortality
serious PRR 0.4no trial data cached
Respiratory failure7047.6
7.1–8.2ROR 7.8 · calibrated p 0.072
7.5 EB05 7.1 · IC025 +2.8
3/3 methods agree
vs other Benzodiazepines: PRR 47.5 (47.5–47.5)
Not in label — unassessedserious PRR 4.6 · 91% clinicianno trial data cached
Nausea6980.7
0.6–0.7ROR 0.7 · calibrated p 0.123
0.7 EB05 0.7 · IC025 -0.7
PRR-only: not supported by EBGM or IC
vs other Benzodiazepines: PRR 6.1 (6.1–6.1)
Not in label — unassessedserious PRR 0.8 · ♀ 72% (drug 48%)no trial data cached
Condition aggravated6971.8
1.7–1.9ROR 1.8 · calibrated p 0.849
1.8 EB05 1.7 · IC025 +0.7
vs other Benzodiazepines: PRR 14.9 (14.9–14.9)
Reporting / coding artifactserious PRR 1.7 · 91% clinicianno trial data cached
Status epilepticus69351.1
47.3–55.1ROR 52.4 · calibrated p 1e-5 ✓
47.9 EB05 45.0 · IC025 +5.4
3/3 methods agree
vs other Benzodiazepines: PRR 83.2 (81.7–84.6)
Likely indication confounding
shares a disease stem with the indications wording
serious PRR 29.6 · 95% clinicianno trial data cached
Tachycardia (fast heart rate)6705.9
5.5–6.4ROR 6.1 · calibrated p 0.146
5.9 EB05 5.5 · IC025 +2.4
3/3 methods agree
vs other Benzodiazepines: PRR 28.0 (28.0–28.0)
Not in label — unassessedserious PRR 3.9no trial data cached

Unlabeled candidate signals

These flagged terms were not found in the FDA label text and do not match an artifact pattern. They are the pairs that would merit a structured assessment (temporality, dose-response, biological plausibility, consistency across databases, trial or cohort evidence). The screen has not done that; string-matching misses label wording, and a strong PRR can still be stimulated reporting, co-medication, or the disease itself.

✓ A hand-written Bradford Hill causality assessment exists for this drug: Oxycodone Hydrochloride ↔ Drug Dependence.

Want to assess one of these properly? The runbook describes the Bradford Hill / trial-evidence workflow used on the assessment page, and handoff_top1000_signals.csv lists the strongest unassessed pairs across all drugs.

Common questions

What are the most reported side effects of Midazolam?

In FDA FAERS, the most frequently co-reported reaction terms for Midazolam are hypotension, seizure, pyrexia, toxicity to various agents, cardiac arrest, acute kidney injury. These are report counts, not rates: FAERS has no denominator, reporting is voluntary and uneven, and a term can be reported because of the illness being treated rather than the drug.

Does Midazolam have an FDA boxed warning?

Yes. The current FDA label carries a boxed warning: RISKS FROM CONCOMITANT USE WITH OPIOIDS; ABUSE, MISUSE, AND ADDICTION; and DEPENDENCE AND WITHDRAWAL REACTIONS Concomitant use of benzodiazepines and opioids may result in profound sedation, respiratory depression, coma, and death . Reserve concomitant prescribing of these drugs for patients for whom alternative treatment options are inadequate.

Do FAERS signals prove that Midazolam causes these side effects?

No. A disproportionality signal (PRR, ROR) means a reaction is reported more often with this drug than with others in the database. That can reflect a real effect, but also the disease being treated, stimulated reporting after news or litigation, co-medications, or how reports are coded. Causality needs temporality, dose-response, biological plausibility, consistency across data sources and, ideally, trial or cohort evidence. This page screens each term against the FDA label and ClinicalTrials.gov results; it does not establish causation.

Sources & methods

Page generated 2026-10-14. Label and PubChem text are retrieved automatically and may lag the current label; always check the current prescribing information. OpenPV is a beta research tool of the Open Source Medicine Foundation.