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Diphenhydramine Hydrochloride
Overview
Active ingredients
Source: NDC Directory| Ingredient | Strength | RxCUI | Monograph |
|---|---|---|---|
| Diphenhydramine Hydrochloride | 50 mg/mL | 1049630 | View |
Forms, strengths and routes
Source: NDC DirectoryPharmacologic classes are listed in the class section below.
Pharmacologic class
Source: NDC Directory| Class | Type | Browse |
|---|---|---|
| Histamine H1 Receptor Antagonists [MoA] | MoA | All 136 members |
| Histamine-1 Receptor Antagonist [EPC] | EPC | All 134 members |
Regulatory status
Source: Drugs@FDANDC Directory| Product | Trade name | Form | Strength | Ingredient | Status | TE | Flags |
|---|---|---|---|---|---|---|---|
| 205723-001 | DIPHENHYDRAMINE HYDROCHLORIDE | INJECTABLE | DIPHENHYDRAMINE HYDROCHLORIDE | Prescription | AP |
Therapeutic equivalence
Source: Orange BookWhat this rating means: Therapeutically equivalent — bioequivalence demonstrated (parenteral aqueous solutions)
Codes beginning with “A” indicate products the FDA considers therapeutically equivalent. Codes beginning with “B” indicate bioequivalence has not been established. See methodology.
Approval history
Source: Drugs@FDA| Type | No. | Action | Status | Date | Review |
|---|---|---|---|---|---|
| Supplement | 2 | Labeling | Approved | August 29, 2023 | Standard |
| Supplement | 1 | Manufacturing (CMC) | Approved | November 30, 2018 | Unknown |
| Original application | 1 | Approved | August 22, 2018 | Standard |
Prescribing information
Source: openFDA Drug LabelingReproduced verbatim from the Structured Product Labeling submitted to the FDA (effective 20260515). This is the manufacturer's labelling text, not a summary and not advice.
Indications and Usage
openFDA Drug LabelingINDICATIONS AND USAGE: Diphenhydramine hydrochloride in the injectable form is effective in adults and pediatric patients, other than premature infants and neonates, for the following conditions when diphenhydramine hydrochloride in the oral form is impractical. Antihistaminic For amelioration of allergic reactions to blood or plasma, in anaphylaxis as an adjunct to epinephrine and other standard measures after the acute symptoms have been controlled, and for other uncomplicated allergic conditions of the immediate type when oral therapy is impossible or contraindicated. Motion Sickness For active treatment of motion sickness. Antiparkinsonism For use in parkinsonism, when oral therapy is impossible or contraindicated, as follows: parkinsonism in the elderly who are unable to tolerate more potent agents; mild cases of parkinsonism in other age groups, and in other cases of parkinsonism in combination with centrally acting anticholinergic agents.
Antihistaminic For amelioration of allergic reactions to blood or plasma, in anaphylaxis as an adjunct to epinephrine and other standard measures after the acute symptoms have been controlled, and for other uncomplicated allergic conditions of the immediate type when oral therapy is impossible or contraindicated.
Motion Sickness For active treatment of motion sickness.
Antiparkinsonism For use in parkinsonism, when oral therapy is impossible or contraindicated, as follows: parkinsonism in the elderly who are unable to tolerate more potent agents; mild cases of parkinsonism in other age groups, and in other cases of parkinsonism in combination with centrally acting anticholinergic agents.
Dosage and Administration
openFDA Drug LabelingDOSAGE AND ADMINISTRATION THIS PRODUCT IS FOR INTRAVENOUS OR INTRAMUSCULAR ADMINISTRATION ONLY. Diphenhydramine hydrochloride in the injectable form is indicated when the oral form is impractical. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit. DOSAGE SHOULD BE INDIVIDUALIZED ACCORDING TO THE NEEDS AND THE RESPONSE OF THE PATIENT. Pediatric Patients, other than premature infants and neonates: 5 mg/kg/24 hr or 150 mg/m 2 /24 hr. Maximum daily dosage is 300 mg. Divide into four doses, administered intravenously at a rate generally not exceeding 25 mg/min, or deep intramuscularly. Adults: 10 mg to 50 mg intravenously at a rate generally not exceeding 25 mg/min, or deep intramuscularly, 100 mg if required; maximum daily dosage is 400 mg.
Contraindications
openFDA Drug LabelingCONTRAINDICATIONS: Use in Neonates or Premature Infants This drug should not be used in neonates or premature infants. Use in Nursing Mothers Because of the higher risk of antihistamines for infants generally, and for neonates and prematures in particular, antihistamine therapy is contraindicated in nursing mothers. Use as a Local Anesthetic Because of the risk of local necrosis, this drug should not be used as a local anesthetic. Antihistamines are also contraindicated in the following conditions: Hypersensitivity to diphenhydramine hydrochloride and other antihistamines of similar chemical structure.
Use in Neonates or Premature Infants This drug should not be used in neonates or premature infants.
Use in Nursing Mothers Because of the higher risk of antihistamines for infants generally, and for neonates and prematures in particular, antihistamine therapy is contraindicated in nursing mothers.
Use as a Local Anesthetic Because of the risk of local necrosis, this drug should not be used as a local anesthetic. Antihistamines are also contraindicated in the following conditions: Hypersensitivity to diphenhydramine hydrochloride and other antihistamines of similar chemical structure.
Warnings
openFDA Drug LabelingWARNINGS: Antihistamines should be used with considerable caution in patients with narrow-angle glaucoma, stenosing peptic ulcer, pyloroduodenal obstruction, symptomatic prostatic hypertrophy, or bladder-neck obstruction. Local necrosis has been associated with the use of subcutaneous or intradermal use of intravenous diphenhydramine hydrochloride. Use in Pediatric Patients In pediatric patients, especially, antihistamines in overdosage may cause hallucinations, convulsions, or death. As in adults, antihistamines may diminish mental alertness in pediatric patients. In the young pediatric patient, particularly, they may produce excitation. Use in the Elderly (approximately 60 years or older) Antihistamines are more likely to cause dizziness, sedation, and hypotension in elderly patients.
Use in Pediatric Patients In pediatric patients, especially, antihistamines in overdosage may cause hallucinations, convulsions, or death. As in adults, antihistamines may diminish mental alertness in pediatric patients. In the young pediatric patient, particularly, they may produce excitation.
Use in the Elderly (approximately 60 years or older) Antihistamines are more likely to cause dizziness, sedation, and hypotension in elderly patients.
Adverse Reactions
openFDA Drug LabelingADVERSE REACTIONS: To report SUSPECTED ADVERSE REACTIONS, contact Fresenius Kabi USA, LLC at 1-800-551-7176 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. The most frequent adverse reactions are underscored. 1. General: Urticaria, drug rash, anaphylactic shock, photosensitivity, excessive perspiration, chills, dryness of mouth, nose and throat. 2. Cardiovascular System: Hypotension, headache, palpitations, tachycardia, extrasystoles. 3. Hematologic System: Hemolytic anemia, thrombocytopenia, agranulocytosis. 4. Nervous System: Sedation , sleepiness , dizziness , disturbed coordination , fatigue, confusion, restlessness, excitation, nervousness, tremor, irritability, insomnia, euphoria, paresthesia, blurred vision, diplopia, vertigo, tinnitus, acute labyrinthitis, neuritis, convulsions. 5. GI System: Epigastric distress , anorexia, nausea, vomiting, diarrhea, constipation. 6. GU System: Urinary frequency, difficult urination, urinary retention, early menses. 7. Respiratory System: Thickening of bronchial secretions , tightness of chest or throat and wheezing, nasal stuffiness.
Drug Interactions
openFDA Drug LabelingDrug Interactions: Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). MAO inhibitors prolong and intensify the anticholinergic (drying) effects of antihistamines.
Description
openFDA Drug LabelingDESCRIPTION Diphenhydramine hydrochloride is an antihistamine drug having the chemical name 2 (Diphenylmethoxy)-N,N-dimethylethylamine hydrochloride. It occurs as a white, crystalline powder, is freely soluble in water and alcohol and has a molecular weight of 291.82. The molecular formula is C 17 H 21 NO·HCl and the structural formula is as follows: Diphenhydramine hydrochloride in the parenteral form is a sterile, pyrogen-free solution. Each mL contains a concentration of 50 mg of diphenhydramine hydrochloride and water for injection, for intramuscular or intravenous use. The solution for parenteral use has been adjusted to a pH between 4 and 6.5 with either sodium hydroxide or hydrochloric acid. Structural Formula
Overdosage
openFDA Drug LabelingOVERDOSAGE: Antihistamine overdosage reactions may vary from central nervous system depression to stimulation. Stimulation is particularly likely in pediatric patients. Atropine-like signs and symptoms; dry mouth; fixed, dilated pupils; flushing; and gastrointestinal symptoms may also occur. Stimulants should not be used. Vasopressors may be used to treat hypotension.
How Supplied / Storage and Handling
openFDA Drug LabelingHOW SUPPLIED Diphenhydramine Hydrochloride Injection, USP in parenteral form is supplied as: Sterile, pyrogen-free solution containing 50 mg diphenhydramine hydrochloride USP in a 1 mL amber color glass vial with yellow bands and white OPC mark, and available in packages of twenty-five packed and five packed in a PVC rondo tray in a single carton. Clear, colorless solution, free from any visible particles, no visible leaks or damage to the container closure system filled in tubular USP Type 1 glass vials. 1 mL fill in 2 mL Vial NDC 72485-101-01 Carton of 25 x 1 mL Vial NDC 72485-101-25 Carton of 5 x 1 mL Vial NDC 72485-101-05 Store at 20° to 25°C (68° to 77°F) [see USP Controlled Room Temperature]. Protect from freezing and light. Retain in carton until time of use. Rx only Keep this and all drugs out of the reach of children. HIGH POTENCY Latex Free Manufactured by: Micro Labs Limited Bangalore-560 099, India Distributed by: Armas Pharmaceuticals, Inc. Freehold, NJ 07728 (USA) M.L.No.: KTK/28/357/2006 Rev. 10/2022
Adverse event reports
Source: openFDA FAERSAttributed to this product's most-reported active ingredient: DIPHENHYDRAMINE HYDROCHLORIDE. Combination products with more than six active ingredients are not attributed, because a report count summed across a long ingredient list measures the list, not the medicine.
Packaging and NDCs
Source: NDC Directory| Package NDC | Product NDC | Labeler | Description | Marketing start |
|---|---|---|---|---|
| 72485-101-05 | 72485-101 | Armas Pharmaceuticals Inc. | 5 VIAL, SINGLE-DOSE in 1 CARTON (72485-101-05) / 1 mL in 1 VIAL, SINGLE-DOSE (72485-101-01) | May 5, 2023 |
| 72485-101-25 | 72485-101 | Armas Pharmaceuticals Inc. | 25 VIAL, SINGLE-DOSE in 1 CARTON (72485-101-25) / 1 mL in 1 VIAL, SINGLE-DOSE (72485-101-01) | May 1, 2019 |
| 55154-9363-5 | 55154-9363 | Cardinal Health 107, LLC | 5 VIAL, SINGLE-DOSE in 1 BAG (55154-9363-5) / 1 mL in 1 VIAL, SINGLE-DOSE | August 1, 2002 |
| 76045-102-10 | 76045-102 | Fresenius Kabi USA, LLC | 24 BLISTER PACK in 1 CARTON (76045-102-10) / 1 SYRINGE, GLASS in 1 BLISTER PACK (76045-102-00) / 1 mL in 1 SYRINGE, GLASS | March 26, 2013 |
| 76045-235-10 | 76045-235 | Fresenius Kabi USA, LLC | 24 BLISTER PACK in 1 CARTON (76045-235-10) / 1 SYRINGE, GLASS in 1 BLISTER PACK (76045-235-01) / 1 mL in 1 SYRINGE, GLASS | June 2, 2025 |
| 51662-1348-1 | 51662-1348 | HF Acquisition Co LLC, DBA HealthFirst | 1 mL in 1 VIAL (51662-1348-1) | November 26, 2018 |
| 51662-1374-3 | 51662-1374 | HF Acquisition Co LLC, DBA HealthFirst | 25 POUCH in 1 BOX (51662-1374-3) / 1 VIAL, SINGLE-DOSE in 1 POUCH (51662-1374-2) / 1 mL in 1 VIAL, SINGLE-DOSE (51662-1374-1) | August 1, 2002 |
| 71872-7180-1 | 71872-7180 | Medical Purchasing Solutions, LLC | 1 VIAL, SINGLE-DOSE in 1 BAG (71872-7180-1) / 1 mL in 1 VIAL, SINGLE-DOSE | October 9, 2019 |
| 84549-101-25 | 84549-101 | ProPharma Distribution | 1 mL in 1 VIAL, SINGLE-DOSE (84549-101-25) | August 27, 2025 |
| 25021-481-01 | 25021-481 | Sagent Pharmaceuticals | 25 VIAL in 1 CARTON (25021-481-01) / 1 mL in 1 VIAL | January 15, 2025 |
| 72485-101 | 72485-101 | Armas Pharmaceuticals Inc. | — | May 1, 2019 |
| 55154-9363 | 55154-9363 | Cardinal Health 107, LLC | — | August 1, 2002 |
| 76045-102 | 76045-102 | Fresenius Kabi USA, LLC | — | March 26, 2013 |
| 76045-235 | 76045-235 | Fresenius Kabi USA, LLC | — | June 2, 2025 |
| 51662-1348 | 51662-1348 | HF Acquisition Co LLC, DBA HealthFirst | — | November 26, 2018 |
| 51662-1374 | 51662-1374 | HF Acquisition Co LLC, DBA HealthFirst | — | August 1, 2002 |
| 71872-7180 | 71872-7180 | Medical Purchasing Solutions, LLC | — | May 1, 2019 |
| 84549-101 | 84549-101 | ProPharma Distribution | — | May 1, 2019 |
| 25021-481 | 25021-481 | Sagent Pharmaceuticals | — | January 15, 2025 |
Sources for this page
| Dataset | Agency | Used for |
|---|---|---|
| NDC Directory | FDA | Identity, ingredients, strengths, forms, routes, labelers, packages |
| Drugs@FDA | FDA | Application, sponsor, submissions, review documents, marketing status |
| Orange Book | FDA | Therapeutic equivalence codes, reference drug flags, patents, exclusivity |
| Drug Labeling | FDA / NLM | Prescribing information reproduced above |
| FAERS | FDA | Adverse event report counts |
Generated September 25, 2026 · 12 sections on this page.