What the label lists and what reports show
Diazoxide side effects
Diazoxide's FDA label: “The most common adverse reactions (10% or more and at least 2% greater than in placebo) in Study 1 were hypertrichosis, edema, hyperglycemia, and rash.” FAERS holds 1,254 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 oedema peripheral (121 reports).
- Generic listed
Check it at the source: the diazoxide FDA label on DailyMed (effective March 26, 2025, Soleno Therapeutics, Inc.); the FDA FAERS public dashboard.
What does the patient leaflet say about side effects?
From the patient leaflet: What are the possible side effects of VYKAT XR?See "What is the most important information I should know about VYKAT XR?" The most common side effects of VYKAT XR also include: increased hair growth all over the body rash These are not all of the possible side effects of VYKAT XR. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088. […] Tell your healthcare provider if you have trouble breathing or get any other signs or symptoms of fluid overload such as swelling of your legs, ankles, or feet, or unusual swelling anywhere in your body.
Source: FDA drug label, Soleno Therapeutics, Inc., effective March 26, 2025 (SPL set 0e745e85-9512-e360-e063-6394a90aebf1), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsThe most common adverse reactions (10% or more and at least 2% greater than in placebo) in Study 1 were hypertrichosis, edema, hyperglycemia, and rash.
Table 3: Adverse Reactions Occurring in ≥5% of Patients with PWS Receiving VYKAT XR and at Least 2% Greater than Placebo in Study 1
| Adverse Reaction | VYKAT XR (N=84) | Placebo (N=42) |
|---|---|---|
| Hypertrichosis | 36% | 14% |
| Edema Edema includes peripheral edema, periorbital edema, swelling face, pulmonary edema,… | 27% | 12% |
| Hyperglycemia Hyperglycemia includes type 2 diabetes mellitus. | 17% | 5% |
| Rash Rash includes contact dermatitis, erythema multiforme, maculo-papular rash, papular… | 12% | 2% |
| Pyrexia | 6% | 0% |
| Arthralgia | 5% | 2% |
| Influenza | 5% | 2% |
| Nasopharyngitis | 5% | 2% |
Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.
From the label: adverse reactions, continuedThe following clinically significant adverse reactions are discussed in greater detail in other sections of the labeling: Hyperglycemia [see Warnings and Precautions (5.1) ] Risk of Fluid Overload [see Warnings and Precautions (5.2) ] Adverse Reactions from Clinical Studies of VYKAT XR in Patients with PWS Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. In the clinical study development program for treatment of hyperphagia in patients aged 4 years and older with PWS, a total of 125 patients received at least 1 dose of VYKAT XR. Patients received dosages of VYKAT XR up to 5.8 mg/kg/day (up to a maximum dosage of 525 mg/day) for up to 4.86 years (median: 3.0 years) in the following studies: Study 1: 13-week, randomized, double-blind, placebo-controlled, parallel-arm study in which 126 patients were randomized in a 2:1 ratio to VYKAT XR or placebo and received at least one dose of VYKAT XR. Study 2-OLE: A long-term, open-label, maintenance treatment period in 115 patients (mean duration 2.6 years; maximum duration 4.3 years) who had previously been enrolled in Study 1. …
Source: FDA drug label, Soleno Therapeutics, Inc., effective March 26, 2025 (SPL set 0e745e85-9512-e360-e063-6394a90aebf1), via openFDA; the full label on DailyMed
What do FAERS reports show?
1,254 reports list diazoxide among the medicines taken, each a report of something that happened, not proof the medicine caused it; 104 are coded as a death and 379 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 18 reactions below, 7 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
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Diazoxide: 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