Medication 7-143 - Benadryl (Diphenhydramine)

CMH EMS & MIH Protocols

Scope of Practice:

• Registered Nurse
• Paramedic
• Community Paramedic

Route(s):

• IM/SQ, IO, IV,

Pharmacodynamics (class and mechanism of action):

• Antihistamine (Blocks H1 histamine receptors).
• Has some sedative effects.

Pharmacokinetics:

• Half-life: 2.4-9.3 hours.
• Onset time: Immediate.
• Peak action time: 1-4 hours.
• Duration of action: 6-8 hours.

• Peak	1	2	3	4	5	6	7	8	hours
  Duration	1	2	3	4	5	6	7	8	hours

Dosing:

• Refer to specific protocol(s) below for dose(s).

Indications:

• Protocol 2-066 - Allergic Reaction.
• Protocol 2-110 - Behavioral.
• Protocol 2-660 - Pain Control.
• Protocol 2-990 - Vomiting.
• Medication 7-406 - Haldol.
• Medication 7-592 - Morphine.
• Medication 7-702 - Phenergan.
• Medication 7-801 - Reglan.

Contraindications:

• Asthma.
• Nursing mothers.

Pregnancy Risk Factor:

• Category B
• No risk in other studies: Animal reproduction studies have failed to demonstrate a risk to the fetus and there are no adequate and well-controlled studies in pregnant women, or animal studies have shown adverse effects, but adequate and well-controlled studies in pregnant women have failed to demonstrate a risk to the fetus in any trimester.

Potential Incompatibilities:

• Medication 7-823 - Sodium Bicarbonate.

Precautions and Adverse Effects:

• May prolong QT interval. 12-lead is indicated after administration.
• May cause dedation, drying and thickening of bronchial secretions, blurred vision, headache, palpitations, dizziness, excitability, wheezing, chest tightness, hypotension, dry mouth, Nausea, vomiting, and/or diarrhea.

Antidote:

• Physostigmine (Antilirium).

Controlled Substance Information:

• Not a scheduled drug
• The DEA and FDA have not identified this drug with a schedule classification.
• DEA number: NA.
• Narcotic: No.
• Street names: NA.

CMH Pre-Hospital Services Mission: "Provide safe, exceptional, and compassionate care to our communities with an emphasis on highly trained and empowered staff."

CMH Mobile Integrated Healthcare Mission: "Provide exceptional, compassionate, and patient-centered care by a mobile collaborative team to improve patient experience, improve quality outcomes, and reduce healthcare costs."

Polk, Hickory, Cedar, & St Clair County EMS Protocols is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.