Prescription medication · Phenothiazine Antiemetic / Antihistamine
promethazine
Also sold as Phenergan. This medicine can treat allergy symptoms like a runny nose or itchy eyes.
Data updated 2026-05-15
- 17,969
- FDA reportsModerately reported
- 3
- InteractionsFew interactions
- In shortage
- FDA status
What the data shows
promethazine (Phenergan) is a prescription Phenothiazine Antiemetic / Antihistamine, reported at a middle-of-the-pack volume (17,969 FDA reports), with 3 documented drug interactions.
Reporting volume reflects how widely a drug is used and studied, not how dangerous it is, a FAERS report documents a temporal association, never proof of cause.
promethazine (Phenergan) is a prescription Phenothiazine Antiemetic / Antihistamine. This medicine can treat allergy symptoms like a runny nose or itchy eyes.
Promethazine suppositories are a medicine that can help with allergies, motion sickness, nausea, vomiting, and sleep problems. It works by blocking certain natural substances in your body.
Verify with FDA → · CMS NADAC pricing →
Drug Shortage Alert
promethazine is currently listed as in shortage by the FDA. Affected manufacturer: Hikma Pharmaceuticals USA, Inc.. Status: Available.
View all drug shortages →Drug Pricing (NADAC)
Generic Price
$2.24/unit
Generic Available
Yes (26 manufacturers)
Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →
NADAC price trail: PROMETHAZINE 12.5 MG SUPPOS
Same CMS presentation as the headline generic unit price above (2 effective dates). Adjacent % compares consecutive NADAC releases for this description only, not a patient out-of-pocket quote. Latest step: -8% vs prior release.
| Effective | NADAC / unit | vs prior | NDCs |
|---|---|---|---|
| April 17, 2024 | $2.44/EA | - | 1 |
| December 18, 2024 | $2.24/EA | -8% | 3 |
What it does
This medicine can treat allergy symptoms like a runny nose or itchy eyes.
Common side effects
Drowsiness, Dry mouth, Blurred vision
Key warnings
Promethazine suppositories should not be used in children under 2 years old because it can cause serious breathing problems, which can be fatal.
The sections below are summarized in plain English from promethazine's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.
How It Works
Promethazine belongs to a class of drugs called antihistamines and antiemetics. It works by blocking histamine, a substance in the body that causes allergic symptoms. It also affects the part of the brain that controls nausea and vomiting.
Side Effects (from patient reports)
Based on 17,969 FDA adverse event reports.
Most-reported reactions
Adverse reactions in FAERS for promethazine, by number of reports
- Nausea
Nausea
2,530 reports
- Vomiting
Vomiting
1,734 reports
- Pain
Pain
1,453 reports
- Fatigue
Fatigue
1,408 reports
- Diarrhoea
Diarrhoea
1,271 reports
- Headache
Headache
1,191 reports
- Dyspnoea
Dyspnoea
1,063 reports
- Anxiety 864
Anxiety
864 reports
- Asthenia 804
Asthenia
804 reports
- Pneumonia 791
Pneumonia
791 reports
What this shows Bars show how often each reaction was reported, not how likely it is to happen, a report records a temporal association, never proof that the drug caused it.
Reports over time
Adverse-event reports filed for promethazine each year to the FDA Adverse Event Reporting System (FAERS).
Year-to-year volume tracks usage, prescribing, and scrutiny, not a change in per-patient risk. Source: FDA FAERS.
Where promethazine sits
promethazine has more FDA adverse-event reports than 52% of the drugs FAERS tracks. A high position reflects how widely a drug is used and watched, not how dangerous it is.
Percentile across all drugs PlainMeds tracks by FAERS report volume. The dot is promethazine; the line is the median (50th percentile).
FDA Adverse Event Report Analysis
Detailed analysis of 17,969 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 1996–2025.
Total Reports
17,969
Reports Mentioning Death
1,754
9.8% of reports — not proof of cause
Hospitalization Reports
7,143
Top Indication
Product Used For Unknown Indication
Gender Distribution
Age Distribution
Most Reported Adverse Reactions (FAERS)
| # | Reaction | Reports |
|---|---|---|
| 1 | NAUSEA | 2,530 |
| 2 | VOMITING | 1,734 |
| 3 | PAIN | 1,453 |
| 4 | FATIGUE | 1,408 |
| 5 | DIARRHOEA | 1,271 |
| 6 | HEADACHE | 1,191 |
| 7 | DYSPNOEA | 1,063 |
| 8 | ANXIETY | 864 |
| 10 | ASTHENIA | 804 |
| 11 | PNEUMONIA | 791 |
| 12 | ABDOMINAL PAIN | 776 |
| 13 | PYREXIA | 768 |
| 14 | DIZZINESS | 752 |
| 15 | MALAISE | 733 |
| 17 | WEIGHT DECREASED | 686 |
Reactions in Death Reports
Reactions in Hospitalization Reports
Source: FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation
Serious Warnings
Promethazine suppositories should not be used in children under 2 years old because it can cause serious breathing problems, which can be fatal. Use with caution in children 2 years and older, and use the lowest effective dose. Avoid giving this medicine with other drugs that can also cause breathing problems.
Known Drug Interactions
Epinephrine - Because of the potential for promethazine HCl to reverse epinephrine's vasopressor effect, epinephrine should NOT be used to treat hypotension associated with Promethazine HCl Suppositories overdose.
Mechanism: Promethazine can block the way epinephrine normally raises blood pressure, which might cause blood pressure to drop even lower.
7.2 Potential for Other Drugs to Affect Penciclovir No clinically significant alterations in penciclovir pharmacokinetics were observed following single-dose administration of 500 mg famciclovir after pretreatment with multiple doses of allopurinol, cimetidine, theophylline, zidovudine, promethazine, when given shortly after an antacid (magnesium and aluminum hydroxide), or concomitantly with emtricitabine. Clinical interaction studies of famciclovir with cimetidine and promethazine, in vitro inhibitors of aldehyde oxidase, did not show relevant effects on the formation of penciclovir.
Mechanism: Promethazine does not significantly affect how famciclovir is processed or activated by the body.
Promethazine: Coadministration of a single dose of zaleplon and promethazine (10 and 25 mg, respectively) resulted in a 15% decrease in maximal plasma concentrations of zaleplon, but no change in the area under the plasma concentration-time curve. However, the pharmacodynamics of coadministration of zaleplon and promethazine have not been evaluated.
Mechanism: Promethazine slightly reduces the highest level of zaleplon in your blood, but the total amount in your body remains about the same.
This is a plain-language summary of FDA-label interaction records and does not provide individual medication-combination directions.
Common Questions
Can I use this for my baby's cold?
Will this medicine make me sleepy?
Can I drink alcohol while using this?
How long does it take for this medicine to work?
What should I do if I feel dizzy?
Can I drive after using this medicine?
Can I use this for asthma?
What if I have an allergic reaction?
Can I use this with other medicines?
How often can I use this medicine?
What are the common side effects of promethazine?
Does promethazine interact with other medications?
What drug class is promethazine?
What pregnancy or breastfeeding source fields are listed for promethazine?
Is promethazine currently in shortage?
Related Medications in Phenothiazine Antiemetic / Antihistamine
Other drugs grouped near promethazine - same-class peers and common alternatives.
alosetron
Lotronex
Alosetron (Lotronex) is a medicine for women with severe diarrhea-predominant irritable bowel syndrome (IBS).
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aprepitant
Emend
Aprepitant (Emend) is a medicine that helps prevent nausea and vomiting.
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bisacodyl
Dulcolax
Bisacodyl is a medicine that helps you have a bowel movement.
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bismuth subsalicylate
Pepto-Bismol
Bismuth subsalicylate (Pepto-Bismol) is a medicine that can treat diarrhea and upset stomach.
Compare with promethazine →
cimetidine
Tagamet
Cimetidine (Tagamet) reduces stomach acid.
Compare with promethazine →
Compare beyond drug class
Nationwide peers by FAERS volume & death-report share
Two PlainMeds-derived comparison paths for promethazine: nearest FDA FAERS report volume and nearest death-report share among drugs with at least 1,000 logged reports, excluding same-class neighbors listed above. Counts reflect reporting volume, not proven individual harm.
Similar FAERS report volume
Nearest drugs by total FAERS reports. This record: 17,969.
Similar death-report share
Nearest drugs by FAERS death-report share. This record: 9.76%.
- nebivolol Δ 0.00 pts · 14,997 reports · Beta-1 Selective Blocker 9.76%death share
- doxycycline Δ 0.00 pts · 64,488 reports · Tetracycline Antibiotic 9.76%death share
- sarilumab Δ 0.01 pts · 23,683 reports · IL-6 Receptor Antagonist 9.77%death share
- cyanocobalamin Δ 0.02 pts · 31,083 reports · Vitamin B12 Supplement 9.78%death share
Medication Guides
Understanding Drug Interactions
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Generic vs Brand Name Drugs
FDA requirements, cost savings, and when the difference matters
Narrow Therapeutic Index Drugs
FDA bioequivalence and label-record context for narrow therapeutic index medicines
Common Drug Interactions
Dangerous medication combinations and how to protect yourself
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What the FDA Data Shows for promethazine
The FDA label for promethazine (sold under brand names such as Phenergan) classifies it as a prescription-only medication in the Phenothiazine Antiemetic / Antihistamine class. This medicine can treat allergy symptoms like a runny nose or itchy eyes. Official labeling lists 4 commonly reported side effects, including Drowsiness, Dry mouth, Blurred vision.
Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 17,969 voluntary reports. The database also lists 3 documented drug interactions derived from FDA labeling, with the top-flagged interaction rated minor severity. NADAC pricing from CMS shows a generic unit cost of $2.24.
Report counts do not establish causation, a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history, and patent information are separate source-record fields. This page is a public FDA/CMS registry and does not provide medical, treatment, substitution, or medication-change directions.
Data Sources
Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Pricing: CMS National Average Drug Acquisition Cost (NADAC). Shortage status: FDA Drug Shortages Database.
FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. This registry does not provide medication decisions.
Last updated: June 30, 2023
PlainMeds is rendered directly from FDA openFDA/FAERS extracts, DailyMed labels, and CMS drug-pricing files, no number is typed in by an editor. FAERS counts, recalls, shortages, and price figures on this page are queried live from those federal extracts. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2026-05-15. Primary sources: openFDA / FAERS, DailyMed and CMS Part B ASP.
Read our methodology - how this data is sourced, computed, and verified.
Data currency: FDA FAERS adverse-event reports through 2025, CMS NADAC acquisition-cost pricing effective December 2024, compiled from the source snapshot dated . See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a data issue.
All federal data sources used on this page
- FDA Orange Book - approved drug products with therapeutic equivalence. accessdata.fda.gov/cder/ob
- FDA DailyMed - NIH-hosted drug labeling for FDA-approved meds. dailymed.nlm.nih.gov
- FDA Adverse Event Reporting System (FAERS) - post-marketing safety surveillance. fda.gov/drugs/faers
- NLM RxNorm - standardized clinical drug nomenclature. nlm.nih.gov/research/umls/rxnorm
- CMS Medicare Part B Drug Average Sales Price Files - federal drug pricing data. cms.gov/medicare/part-b-drugs/asp
- FDA Drug Shortages Database - current and resolved drug shortage tracking. accessdata.fda.gov/drugshortages