Pharmacologic class (EPC) · 4 drug pages

Arteriolar vasodilator: adverse event reports filed with FDA

43,259 reports list a drug in this class as a suspect or interacting product, 2004–2026.

Read first · FDA's statement on these data

Adverse event reports submitted to FDA do not undergo extensive validation or verification. Therefore, a causal relationship cannot be established between product and reactions listed in a report. While a suspected relationship may exist, it is not medically validated and should not be the sole source of information for clinical decision making or other assumptions about the safety or efficacy of a product. Additionally, it is important to remember that adverse event reports represent a small percentage of total usage numbers of a product. Common products may have a higher number of adverse events due to the higher total number of people using the product. openFDA, FDA

FDA adds: "There is no certainty that the reported event (adverse event or medication error) was actually due to the product. FDA does not require that a causal relationship between a product and event be proven, and reports do not always contain enough detail to properly evaluate an event." The information in these reports "cannot be used to estimate the incidence of these events."

Do not rely on openFDA to make decisions regarding medical care. While we make every effort to ensure that data is accurate, you should assume all results are unvalidated.

Not medical advice. This site counts what was reported to FDA. Questions about a medicine or device belong with a pharmacist or clinician.

43,259
reports across the class: 0.2% of all reports; 1,943
reports, 12 months to June 2026: 2,852 in the 12 months before; 10.6%
marked serious by the reporter: 57.4% across all reports; 4
drugs with a page: brand and generic names counted separately

Arteriolar vasodilator is a pharmacologic class (an FDA Established Pharmacologic Class) with 4 drug pages on this site. Together those drugs are listed as a suspect or interacting product in 43,259 adverse event reports received by FDA, 0.2% of the database, from January 2004 to June 2026.

1,943 reports arrived in the 12 months to June 2026, down 32% from 2,852 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. 10.6% of the class's reports are marked serious, 1.1% record death among the outcomes and 4.5% record hospitalisation, as reported.

Across the class the reactions recorded most often are adverse drug reaction (19.8%), drug ineffective (18%) and alopecia (8.4%). The class median share shown beside each term is the middle value across the member drugs; it is the comparison used on every drug page in this class.

The members table is 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."

Drugs in the class

Drug	Name type	Reports	Latest 12 months	Marked serious	Top term recorded
Minoxidil	generic	28,593	1,277	6.2%	Adverse drug reaction
Womens Rogaine UnscentedMinoxidil	brand	11,409	334	0.7%	Alopecia
Hydralazine hydrochloride	generic	2,488	260	85.6%	Anti-neutrophil cytoplasmic antibody positive vasculitis
Biotin	generic	769	72	78.8%	Dyspnoea

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."

Reports by month, five years

FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases.

Reactions recorded across the class

share of class reports recording the termmedian drug in the class

Adverse drug reactiona harmful or unpleasant reaction reported to a medicine19.8%8,571
Drug ineffectivethe medicine did not work as expected18%7,791
Alopeciahair loss8.4%3,628
Application site pruritusitching where the product was applied6.7%2,908
Off label useused for a purpose or in a way not on the label5.3%2,285
Application site irritation3.3%1,418
Application site pain3.3%1,409
Overdosea dose above the recommended amount3.3%1,406
Hair texture abnormal3.2%1,378
Headachehead pain3%1,288
Incorrect dose administeredthe wrong dose was given2.9%1,276
Product use in unapproved indicationused for a purpose not on the label2.6%1,143
Wrong technique in product usage processthe product was used in the wrong way2.6%1,129
Inappropriate schedule of product administrationthe product was taken at the wrong times2.6%1,127
Pruritusitching2%878
Rashskin rash1.9%819
Application site dryness1.9%818
Product formulation issue1.8%798
Application site erythemaredness where the product was applied1.8%761
Product use issuea problem in how the product was used1.8%759
Condition aggravatedthe condition being treated got worse1.7%755
Dizzinesslight-headedness or unsteadiness1.7%715
Inappropriate schedule of drug administrationthe medicine was taken at the wrong times1.6%704
Hair colour changes1.6%697
Product administered at inappropriate site1.6%693

Solid bar: share of all class reports. Hollow bar: the median share across the 4 member drugs, the reference used on each member's page. One report can record several terms.

Outcomes, patients and reporters

Outcomes recorded

Death1.1%494

Life-threatening0.9%408

Hospitalisation (initial or prolonged)4.5%1,946

Disability0.6%270

Congenital anomaly0.2%99

Other serious7.5%3,265

Not serious89.4%38,675

Patient age

Under 20.3%126

2 to 110.2%98

12 to 170.1%62

18 to 445%2,178

45 to 649.2%3,969

65 to 747.3%3,153

75 and over5.6%2,410

Age not given72.3%31,263

Who reported

Physician2.9%1,247

Pharmacist1%419

Other health professional5.5%2,376

Lawyer0%8

Consumer or non-health professional90.1%38,981

Not given0.5%228

Grey bar: all 20,646,523 reports in the database. Outcome flags are as the reporter set them and are not verified by FDA.

Questions about Arteriolar vasodilator reports

Which drugs are in the Arteriolar vasodilator class on this site?

Minoxidil, Womens Rogaine Unscented, Hydralazine hydrochloride and Biotin. Class membership comes from the pharmacologic class (EPC) on the drug's FDA label.

How many reports does the class have?

43,259 reports through June 2026, 1,943 of them in the latest 12 months. A report listing two drugs of the class counts once for each.

What reactions are recorded most often?

adverse drug reaction (19.8%), drug ineffective (18%), alopecia (8.4%), application site pruritus (6.7%) and off label use (5.3%).

Can the members table be used to rank the drugs?

No. 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." Drugs differ in how many people take them, in the conditions they treat, in time on the market and in how diligently reports are collected.

How do I report an adverse event?

Through FDA MedWatch (Form FDA 3500, or 1-800-FDA-1088) or to the manufacturer. 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 class is the Established Pharmacologic Class most often attached to a drug's reports by openFDA's label harmonisation, or from the NDC Directory where reports carry none. 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.