Diphenhydramine vs Cetirizine: side effects in FDA adverse event reports
At a glance
| Diphenhydramine | Cetirizine | |
|---|---|---|
| Drug class | – | – |
| Brand names | Nightime Sleep Aid | Cetirizine Hydrochloride |
| FAERS reports | 164,753 | 163,560 |
| Serious | 71% | 55% |
| Death outcome | 22,785 | 10,788 |
| Boxed warning | No | No |
Signals both drugs share
| Reaction | Diphenhydramine | Cetirizine | Label screen (A / B) |
|---|---|---|---|
| Deep vein thrombosis postoperative | 318 · PRR 24.5 | 1,299 · PRR 255.4 | No label text to screen / Not in label — unassessed |
| Adjustment disorder with depressed mood | 335 · PRR 25.2 | 1,046 · PRR 138.8 | No label text to screen / Not in label — unassessed |
| Dislocation of vertebra | 352 · PRR 23.8 | 1,024 · PRR 109.4 | No label text to screen / Not in label — unassessed |
| Lupus vulgaris | 359 · PRR 54.8 | 785 · PRR 252.1 | No label text to screen / Not in label — unassessed |
| Retinitis | 384 · PRR 37.8 | 671 · PRR 86.0 | No label text to screen / Not in label — unassessed |
| Temperature regulation disorder | 482 · PRR 35.8 | 459 · PRR 33.9 | No label text to screen / Not in label — unassessed |
| Seronegative arthritis | 163 · PRR 21.5 | 329 · PRR 52.9 | No label text to screen / Not in label — unassessed |
| Vaginal flatulence | 200 · PRR 244.2 | 171 · PRR 163.5 | No label text to screen / Not in label — unassessed |
Labeled signals distinctive to Diphenhydramine
- None stood out among the strongest labeled signals.
Labeled signals distinctive to Cetirizine
- Glossodynia — n=8,134, PRR 73.1 Labeled (related wording)
- Muscle injury — n=3,851, PRR 113.5 Labeled (related wording)
Common questions
Which has more reported side effects, Diphenhydramine or Cetirizine?
Diphenhydramine has 164,753 FAERS reports and Cetirizine 163,560. 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 55%) is a better like-for-like signal of the kind of problems reported.
Which side effects do Diphenhydramine and Cetirizine share?
Both drugs carry disproportionality signals for deep vein thrombosis postoperative, adjustment disorder with depressed mood, dislocation of vertebra, lupus vulgaris, retinitis. Shared signals often reflect a shared drug class or the condition both are used for.
Is Diphenhydramine or Cetirizine 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.