What the label lists and what reports show

Promethazine side effects

Promethazine's FDA label lists its adverse reactions in its own words. FAERS holds 18,478 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is pain (1,473 reports).

Generic listed
In shortage

Check it at the source: the promethazine FDA label on DailyMed (effective March 13, 2026, KVK-Tech, Inc.); the FDA FAERS public dashboard.

What does the label list?

From the label: adverse reactions
Central Nervous System: Drowsiness is the most prominent CNS effect of this drug. Sedation, somnolence, blurred vision, dizziness; confusion, disorientation, and extrapyramidal symptoms such as oculogyric crisis, torticollis, and tongue protrusion; lassitude, tinnitus, incoordination, fatigue, euphoria, nervousness, diplopia, insomnia, tremors, convulsive seizures, excitation, catatonic-like states, hysteria. Hallucinations have also been reported. Cardiovascular: Increased or decreased blood pressure, tachycardia, bradycardia, faintness. Dermatologic: Dermatitis, photosensitivity, urticaria. Hematologic: Leukopenia, thrombocytopenia, thrombocytopenic purpura, agranulocytosis. Gastrointestinal: Dry mouth, nausea, vomiting, jaundice. Respiratory: Asthma, nasal stuffiness, respiratory depression (potentially fatal) and apnea (potentially fatal). (See WARNINGS: Respiratory Depression). …

Source: FDA drug label, KVK-Tech, Inc., effective March 13, 2026 (SPL set 7a137adf-39b7-4b14-80da-c3cac9ad562a), via openFDA; the full label on DailyMed

What do FAERS reports show?

18,478 reports list promethazine among the medicines taken, each a report of something that happened, not proof the medicine caused it; 1,793 are coded as a death and 7,330 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 21 reactions below, 3 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.

Reports received each year

The 25 most reported reactions

Nausea (a use or a product term, not a reaction)2,588
Vomiting (a use or a product term, not a reaction)1,774
Pain1,473
Fatigue (named in the label)1,443
Diarrhoea1,298
Headache1,217
Dyspnoea1,104
Drug Ineffective (a use or a product term, not a reaction)880
Anxiety (named in the label)874
Asthenia813
Pneumonia813
Abdominal Pain792
Pyrexia781
Dizziness (named in the label)773
Malaise744
Off Label Use (a use or a product term, not a reaction)738
Arthralgia700
Weight Decreased698
Drug Hypersensitivity674
Fall642
Depression607
Dehydration582
Back Pain572
Chest Pain564
Decreased Appetite555

Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms

What next?

Promethazine: the full record: label, generics, price, shortages, recalls
Report a side effect to the FDA: MedWatch
Side effects hub: the most reported medicines and reactions