Indication

Diphenhydramine for Allergic reaction

1,335 under review120 sources109 named agencies35 statesas of 2026-09-20

Adult dosing has a median of 37.5 mg across 115 published protocols, with the middle half between 25 and 50.

120sources

109named agencies

35states

333entries

105named here

1,335 rows are under review across the census and excluded from every number on this page. How that works.

Adultmg

115sources

105named agencies

34states

156entries

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 drug five times still gets one vote.

Routes

IV/IO/IM 31%
IV/IM 19%
PO 17%
IM 8%
IV/IO/IM/PO 8%
IV 6%
IV/IM/PO 5%
IV/IO 4%
IO/IM 1%
IV/PO 1%

United States EMS Protocol Census, n=115 protocols from 105 named agencies / 34 states, updated Sep 2026

Pediatric, weight-basedmg/kg

106sources

98named agencies

32states

153entries

0kept as written

min	p25	median	p75	max
0.5	1	1	1	1.5

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

Routes

IV/IO/IM 29%
IV/IM 21%
PO 16%
IM 10%
IV 8%
IV/IO/IM/PO 7%
IV/IM/PO 4%
IV/IO 4%
IO/IM 1%
IV/PO 1%

United States EMS Protocol Census, n=106 protocols from 98 named agencies / 32 states, updated Sep 2026

Adult, weight-basedmg/kg

14sources

13named agencies

10states

22entries

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 drug five times still gets one vote.

Routes

IV/IM 23%
PO 23%
IM 14%
IV 14%
IV/IO/IM/PO 14%
IV/IO/IM 9%
IV/IM/PO 5%

United States EMS Protocol Census, n=14 protocols from 13 named agencies / 10 states, updated Sep 2026

Pediatricmg

2sources

2named agencies

2states

2entries

1kept as written

Below 5 sources, so no distribution is published for this group — only the counts above.

Routes

PO 100%

United States EMS Protocol Census, n=2 protocols from 2 named agencies / 2 states, updated Sep 2026

Named agencies

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