Indication

Diphenhydramine for Allergic reaction

156 sources134 named agencies44 statesas of 2026-10-31

Adult dosing has a median of 37.5 mg across 149 published protocols, with the middle half between 25 and 50.

156sources

134named agencies

44states

436entries

130named here

Doses far off from what other protocols give are likely misreads, so they are left out until checked. How that works.

Adultmg

149sources

129named agencies

44states

206entries

0kept as written

min	p25	median	p75	max
12.5	25	37.5	50	50

Values in mg. One value per source (that source's median), so a document listing a medication five times still gets one vote.

Routes

IV/IO/IM 35%
IV/IM 20%
PO 15%
IM 7%
IV 6%
IV/IO/IM/PO 6%
IV/IM/PO 6%
IV/IO 3%
IV/IO/PO 1%
IV/PO 1%

United States EMS Protocol Census, n=149 protocols from 129 named agencies / 44 states, updated Oct 2026

Pediatric, weight-basedmg/kg

146sources

128named agencies

42states

204entries

0kept as written

min	p25	median	p75	max
0.5	1	1	1	2

Values in mg/kg. One value per source (that source's median), so a document listing a medication five times still gets one vote.

Routes

IV/IO/IM 34%
IV/IM 22%
PO 14%
IM 7%
IV 7%
IV/IO/IM/PO 7%
IV/IM/PO 5%
IV/IO 3%
IV/PO 1%

United States EMS Protocol Census, n=146 protocols from 128 named agencies / 42 states, updated Oct 2026

Adult, weight-basedmg/kg

11sources

9named agencies

9states

18entries

0kept as written

min	p25	median	p75	max
1	1	1	1	1

Values in mg/kg. One value per source (that source's median), so a document listing a medication five times still gets one vote.

Routes

IV/IM 33%
PO 28%
IM 11%
IV 11%
IV/IO/IM/PO 11%
IV/IO/IM 6%

United States EMS Protocol Census, n=11 protocols from 9 named agencies / 9 states, updated Oct 2026

Pediatricmg

7sources

6named agencies

6states

8entries

0kept as written

min	p25	median	p75	max
6.25	12.5	12.5	18.75	25

Values in mg. One value per source (that source's median), so a document listing a medication five times still gets one vote.

Routes

PO 88%
IV/IM 13%

United States EMS Protocol Census, n=7 protocols from 6 named agencies / 6 states, updated Oct 2026

Named agencies with a page130

Agencies whose protocols are a public record are named here. Their own doses are on their own pages; this list carries no values.