Drugs › Central alpha-2 adrenergic agonist
Generic name
Clonidine hydrochloride: adverse event reports filed with FDA
1,842 reports list it as a suspect or interacting product, 2005–2026. Class: Central alpha-2 adrenergic agonist. Also reported as Clonidine Hydrochloride Tablets Usp, Clonidine Hcl Injection, Clonidine Hcl Tablets.
- 1,842
- reports as suspect product
- 0% of all reports · about 86 a year
- 260
- reports, 12 months to June 2026
- 363 in the 12 months before
- 77.8%
- marked serious by the reporter
- 75.5% across the class
- 31.9%
- record death among outcomes, as reported
- 587 reports · not verified by FDA
Between March 2005 and June 2026, 1,842 adverse event reports received by FDA list clonidine hydrochloride, a generic name as a suspect or interacting product. Reports that mention it only as a concomitant medication (3,777) are left out of every figure here.
In the 12 months to June 2026, 260 reports listed it, down 28% from 363 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. Over its reporting history that is about 86 reports a year and 0% of the 20,646,523 reports in the database, and 5.8% of the reports for the central alpha-2 adrenergic agonist class. How many people take it is not in the data, so a count is not a rate of occurrence.
The MedDRA terms listed most often are hypertension (27.8%), headache (22.9%) and hypersensitivity (22.2%). A report can list several reactions, so shares add to more than 100%; 580 different terms appear across these reports. Hypertension is recorded in 27.8% of these reports, a larger share than in the median central alpha-2 adrenergic agonist drug (2.3%).
77.8% of the reports are marked serious by the reporter (75.5% across the class); 31.9% record death among the outcomes and 25.4% record hospitalisation, as reported. 50.4% of the reports came from other health professionals, and the largest patient age group is 45 to 64 (15.2%). FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event."
Reports by month, five years
Reports by the month FDA received them. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases.
By year received
2026 covers reports received through June 2026 only.
Reactions recorded in the reports
share of Clonidine hydrochloride reports recording the termmedian drug in central alpha-2 adrenergic agonist
- Hypertensionhigh blood pressure27.8%512
- Headachehead pain22.9%422
- Hypersensitivityan allergic-type reaction22.2%409
- Hepatic enzyme increasedraised liver enzymes20.1%371
- Infusion related reactiona reaction during or soon after an infusion20.1%370
- Off label useused for a purpose or in a way not on the label18.6%343
- Painpain, site not specified18.2%336
- Joint swellinga swollen joint17.8%328
- Prescribed overdose17.4%320
- Fatiguetiredness15.4%283
- Drug ineffectivethe medicine did not work as expected14.8%272
- Overdosea dose above the recommended amount14.6%269
- Upper respiratory tract infectiona cold or similar infection14.3%264
- Pyrexiafever13.5%249
- Rashskin rash13.5%249
- Rheumatoid arthritisrheumatoid arthritis, an inflammatory joint disease13.1%241
- Psoriasispsoriasis, a skin condition13%240
- Hyperhidrosisexcessive sweating12.9%238
- Product use issuea problem in how the product was used12.8%235
- Immunodeficiency12.4%229
- Infectionan infection, type not specified12.4%229
- Food allergy12.1%222
- Exposure during pregnancythe medicine was taken during pregnancy11.9%219
- Asthmaasthma11.8%218
- Intentional product misusedeliberate use not as intended11.2%207
- Hypoaesthesianumbness10.9%201
- Drug intolerancethe medicine was not tolerated10.5%194
- Hypercholesterolaemia10.5%193
- Nauseafeeling sick10.5%193
- Impaired healingslow healing9.4%173
Top 30 of 580 MedDRA preferred terms recorded across these reports, with a plain-language gloss where one is available. One report can record several terms. The hollow bar is the median share across the 13 drugs in the central alpha-2 adrenergic agonist class; it describes the reports, not the patients. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."
Outcomes recorded
Outcome flags as the reporter set them; a report can carry several, and "other serious" is FDA's own category for serious reports outside the named outcomes. Grey bar: all 31,745 reports in the class. FDA has not verified any outcome and states that the reports "cannot be used to estimate the incidence of these events."
Patients and reporters
Patient age
Patient sex
Who reported
Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 46.4% of reports give the United States as the country of the event or reporter.
Reason for use recorded
| Indication as recorded (MedDRA) | Reports | Share |
|---|---|---|
| Hypertension | 200 | 10.9% |
| Eczema | 108 | 5.9% |
| Blood pressure increased | 40 | 2.2% |
| Insomnia | 14 | 0.8% |
| Attention deficit hyperactivity disorder | 12 | 0.7% |
| Blood pressure measurement | 10 | 0.5% |
The indication field is filled in by the reporter and is often blank; shares are of all 1,842 reports.
In context
| Measure | Clonidine hydrochloride | Central alpha-2 adrenergic agonist | All reports |
|---|---|---|---|
| Reports as suspect product | 1,842 | 31,745 | 20,646,523 |
| Share of that pool | — | 5.8% | 0% |
| Reports, latest 12 months | 260 | — | 1,332,454 |
| Marked serious | 77.8% | 75.5% | 57.4% |
| Death recorded among outcomes, per 1,000 reports | 319 | 162 | 91 |
| Hospitalisation recorded, per 1,000 reports | 254 | 304 | 213 |
| Consumer-filed share | 27.6% | 27.5% | 45.8% |
| Top term, share of reports | Hypertension 27.8% | median 2.3% | 1% |
Shares are of reports, not of patients treated. The number of people taking a product is not in the data, so none of these figures is a rate, and differences between columns reflect who takes a product, who reports and how long it has been sold. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."
Other drugs in the central alpha-2 adrenergic agonist class
| Drug | Name type | Reports | Latest 12 months | Marked serious |
|---|---|---|---|---|
| Clonidine | generic | 11,712 | 713 | 79.2% |
| Tizanidine | generic | 4,259 | 376 | 69.8% |
| Methyldopa | generic | 2,659 | 138 | 95.8% |
| Intuniv | brand | 2,180 | 48 | 75.8% |
| Dexmedetomidine | generic | 1,653 | 160 | 93.2% |
| Guanfacine | generic | 1,445 | 214 | 61.7% |
| Dexmedetomidine hydrochloride | generic | 1,436 | 134 | 98% |
| Zanaflex | brand | 1,166 | 10 | 54.5% |
| Tizanidine hydrochloride | generic | 1,051 | 104 | 80.3% |
| Clonidine transdermal system | generic | 873 | 86 | 15% |
| Catapres-TTS-1 | brand | 871 | 0 | 18% |
| Precedex | brand | 598 | 20 | 78.1% |
Ordered by report count for navigation only. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic." A brand and its generic are separate rows because reporters name them separately.
Questions about Clonidine hydrochloride reports
How many adverse event reports has FDA received for Clonidine hydrochloride?
1,842 reports list Clonidine hydrochloride as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 260 of them arrived in the latest 12 months. Another 3,777 list it only as a concomitant medication.
What reactions are recorded in Clonidine hydrochloride reports?
hypertension (27.8%), headache (22.9%), hypersensitivity (22.2%), hepatic enzyme increased (20.1%) and infusion related reaction (20.1%). These are MedDRA preferred terms coded from what the reporter described; a report can list several, and a term's presence is not a finding that Clonidine hydrochloride was responsible.
How serious are the reports?
77.8% are marked serious by the reporter. Among the outcomes recorded, 31.9% of reports include death and 25.4% include hospitalisation. FDA has not verified these outcomes and states that the reports "cannot be used to estimate the incidence" of the events.
Who files these reports?
other health professional (50.4%), consumer or non-health professional (27.6%) and physician (12.7%). Most reports reach FDA through the manufacturer, which must forward reports it receives.
Are reports for Clonidine hydrochloride rising?
260 reports in the 12 months to June 2026, down 28% from 363 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. Counts also move with how many people take a product, its time on the market and publicity.
Do these reports show that Clonidine hydrochloride was responsible for these reactions?
No. FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event." The reaction may relate to the condition being treated, to other medicines, or to something else.
Is this a list of the side effects of Clonidine hydrochloride?
No. It is a count of what was reported to FDA. The adverse reactions observed in clinical studies are printed on the FDA-approved label, which a pharmacist or clinician can go through with you.
How do I report an adverse event?
Consumers and health professionals can report to FDA through MedWatch (Form FDA 3500 online, or 1-800-FDA-1088), or to the manufacturer, which must pass reports on. See the guide on how to report.
Where this comes from. Counts are built from the openFDA Drug Adverse Event (FAERS) bulk export released 28 Sep 2026, which holds reports FDA received through 30 Jun 2026. Drug names are as reported, resolved to the brand or generic name on the FDA label where openFDA's harmonisation matched them; classes are the pharmacologic class (EPC) from the label and the National Drug Code Directory of 17 Sep 2026. A report counts here when it lists Clonidine hydrochloride as a suspect or interacting product; reports listing it only as a concomitant medication (3,777) are excluded. No report narrative, lot number, patient detail or reporter identity is published. See the methodology and sources; FDA's record is authoritative, and corrections are handled within five working days.
Drug data (FAERS) through 30 Jun 2026; device data (MAUDE) through 31 Aug 2026. Not medical advice.