Diphenhydramine vs Loratadine: side effects in FDA adverse event reports
At a glance
| Diphenhydramine | Loratadine | |
|---|---|---|
| Drug class | – | – |
| Brand names | Nightime Sleep Aid | – |
| FAERS reports | 164,753 | 106,935 |
| Serious | 71% | 47% |
| Death outcome | 22,785 | 4,661 |
| Boxed warning | No | No |
Signals both drugs share
| Reaction | Diphenhydramine | Loratadine | Label screen (A / B) |
|---|---|---|---|
| Infusion site swelling | 897 · PRR 21.6 | 164 · PRR 5.3 | No label text to screen / No label text to screen |
| Infusion site pruritus | 641 · PRR 32.8 | 99 · PRR 6.4 | No label text to screen / No label text to screen |
| Infusion site haemorrhage | 438 · PRR 19.8 | 100 · PRR 6.2 | No label text to screen / No label text to screen |
| Infusion site discharge | 366 · PRR 34.5 | 74 · PRR 8.8 | No label text to screen / No label text to screen |
Labeled signals distinctive to Diphenhydramine
- None stood out among the strongest labeled signals.
Labeled signals distinctive to Loratadine
- None stood out among the strongest labeled signals.
Common questions
Which has more reported side effects, Diphenhydramine or Loratadine?
Diphenhydramine has 164,753 FAERS reports and Loratadine 106,935. More reports does not mean more dangerous: volume follows how widely and how long a drug has been used, prescription vs over-the-counter status, and publicity. The seriousness share (71% vs 47%) is a better like-for-like signal of the kind of problems reported.
Which side effects do Diphenhydramine and Loratadine share?
Both drugs carry disproportionality signals for infusion site swelling, infusion site pruritus, infusion site haemorrhage, infusion site discharge. Shared signals often reflect a shared drug class or the condition both are used for.
Is Diphenhydramine or Loratadine safer?
FAERS cannot answer that: it has no denominator and no comparator. Use this page to see which risks are already on each label and which signals are unlabeled, then check the prescribing information and your clinician for your situation.
Sources: openFDA FAERS pair statistics (OpenPV build 2026-09-14), FDA labels via openFDA, openFDA count queries for seriousness and deaths. Pair chosen because it is a commonly searched comparison. Generated 2026-10-08.