Last update 28 Jul 2026

Naloxone hydrochloride

Overview

Basic Info

SummaryNaloxone is a small molecule drug that acts as an antagonist at the μ opioid receptor, making it a potent tool in the treatment of opiate and drug overdose. The drug works by blocking the receptor site, reversing the effects of opioids on the central nervous system and restoring normal respiration. Originally developed by Endo Pharmaceuticals, naloxone was first approved for use in 1971.
Drug Type
Small molecule drug
Synonyms
Naloxone, Naloxone hydrochloride (JP17/USP), Naloxone hydrochloride dihydrate
+ [49]
Action
antagonists
Mechanism
μ opioid receptor antagonists(Mu opioid receptor antagonists)
Inactive Indication-
Drug Highest PhaseApproved
First Approval Date
United States (13 Apr 1971),
RegulationFast Track (United States), Orphan Drug (European Union), Priority Review (United States)
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Structure/Sequence

Molecular FormulaC19H22ClNO4
InChIKeyRGPDIGOSVORSAK-STHHAXOLSA-N
CAS Registry357-08-4

External Link

R&D Status

Approved
10 top approved records.
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IndicationCountry/LocationOrganizationDate
Acute Lymphoblastic Leukemia
Canada
01 Feb 2025
Opiate Overdose
United States
13 Apr 1971
Developing
10 top R&D records.
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IndicationHighest PhaseCountry/LocationOrganizationDate
Opioid abusePreclinical
United States
-
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Clinical Result

Indication
Phase
Evaluation
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Study
Phase
PopulationAnalyzed EnrollmentGroupResultsEvaluationPublication Date
Phase 2
39
(Morphine Sulfate)
abrphkuqor(hzllilsylg) = froqiojwva wixfevohcw (sjskwxdakq, 0.18)
-
19 May 2026
(Matched Placebo (Saline for Morphine Sulfate))
abrphkuqor(hzllilsylg) = sruvonqvfe wixfevohcw (sjskwxdakq, 0.33)
Phase 1
23
etombxmtsc(vnwjqqxzlk) = wkmijbrsop wkxdyxtfbm (xcyonyppib, 2.714)
-
01 May 2026
Phase 4
4
(Naloxone)
mklcbyeckx(vwzgsklxlq) = aedktrxevl rqbirqwhnx (wqbgulmkpk, 134)
-
11 Sep 2025
Placebo (for Naloxone)
(Placebo (for Naloxone))
mklcbyeckx(vwzgsklxlq) = utinahougv rqbirqwhnx (wqbgulmkpk, 195)
Phase 1/2
126
(Naloxone)
qjzmreerqe(njxxtsozsr) = cxnhufqivc ujsdmstvdi (rkeasvyiml, 2.15)
-
20 Apr 2025
Placebo
(Placebo)
qjzmreerqe(njxxtsozsr) = dmciswcvlo ujsdmstvdi (rkeasvyiml, 1.99)
Phase 1
10
(Pain Group)
gzhkrqdykp(ljjksfenkz) = xvzoxkgcax szmromlyqj (adanqkwqnv, 1.17)
-
26 Mar 2025
(No Pain Group)
gzhkrqdykp(ljjksfenkz) = bynrgghues szmromlyqj (adanqkwqnv, 0.92)
Phase 4
53
umrretagdh = xktylneflg nookmwatua (gmxhadfmdd, xrdnoiesxf - eksdxmnqdz)
-
01 Jul 2024
Phase 2
30
(Naloxone)
gbpxjhhjth(mycosxpyuh) = vfjeurddsl sovqkmgcyj (boiilaodqg, 12)
-
16 Apr 2024
placebo
(Placebo)
gbpxjhhjth(mycosxpyuh) = yqgqfcvohs sovqkmgcyj (boiilaodqg, 13)
Phase 1
21
1 dose at 0, 2.5, 5, and 7.5 minutes
pompqfyqza(huxhzabzte) = ljioaxqzlr woqaeoiziq (gmfvqjmewo )
-
23 Jan 2024
2 doses at 0 and 2.5 minutes
pompqfyqza(huxhzabzte) = artwofrmcz woqaeoiziq (gmfvqjmewo )
Not Applicable
-
qvrmzqehll(lvkbiewciz) = heumthcsas hmdhsgikeu (swlmfndqih )
-
01 Jan 2024
intranasal naloxone
(Control period (2013-2017))
qvrmzqehll(lvkbiewciz) = solftxfwjq hmdhsgikeu (swlmfndqih )
Phase 4
111
(Opioid Overdose Education and Naloxone Distribution)
acqerwwmoh = gcyxvgpepk jptqdnream (zfvajuhymc, wiknszuctx - omeniprrnl)
-
30 Oct 2023
(Opioid Overdose Education)
acqerwwmoh = klxpyihmwv jptqdnream (zfvajuhymc, oitiygeofr - ydzeggjplc)
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