Medical Editor: John P. Cunha, DO, FACOEP
What Is Rayos?
Rayos (prednisone) is a corticosteroid prescribed for several diseases and conditions including atopic dermatitis, seasonal or perennial allergic rhinitis, congenital adrenal hyperplasia, treatment of acute leukemia and aggressive lymphomas, asthma, psoriatic arthritis, and more.
What Are Side Effects of Rayos?
Common side effects of Rayos include:
- fluid retention,
- elevated blood sugar,
- increased blood pressure,
- behavioral and mood changes,
- increased appetite,
- weight gain,
- trouble sleeping (insomnia),
- nervousness,
- fast or slow heart rate,
- lightheadedness and fainting,
- acne,
- facial redness,
- increased sweating,
- rash,
- stretch marks,
- hives,
- bloating,
- nausea,
- feeling unwell (malaise),
- muscle weakness,
- depression,
- headache,
- spinning sensation (vertigo), and
- vision problems.
Dosage for Rayos
The dosage of Rayos depends upon the severity of the disease and the response of the patient. Rayos comes in 1 mg, 2 mg, and 5 mg prednisone delayed-release tablets.
What Drugs, Substances, or Supplements Interact with Rayos?
Rayos may interact with phenytoin, diuretics, digitalis, digoxin, rifampin, amphotericin B, cyclosporine, insulin or diabetes medicines, ketoconazole, birth control pills and hormone replacement therapy, blood thinners, aspirin or other NSAIDS, or barbiturates. Tell your doctor all medications and supplements you use.
Rayos During Pregnancy and Breastfeeding
Rayos should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Caution should be exercised when Rayos is administered to a nursing woman. If Rayos must be prescribed to a breastfeeding mother, the lowest dose should be prescribed to achieve the desired clinical effect.
Additional Information
Our Rayos (prednisone) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

SLIDESHOW
Fungal Skin Infections: Types, Symptoms, and Treatments See SlideshowSIDE EFFECTS
Common adverse reactions for corticosteroids include fluid retention, alteration in glucose tolerance, elevation in blood pressure, behavioral and mood changes, increased appetite and weight gain.
Allergic Reactions: Anaphylaxis, angioedema
Cardiovascular: Bradycardia, cardiac arrest, cardiac arrhythmias, cardiac enlargement, circulatory collapse, congestive heart failure, fat embolism, hypertension, hypertrophic cardiomyopathy in premature infants, myocardial rupture following recent myocardial infarction, pulmonary edema, syncope, tachycardia, thromboembolism, thrombophlebitis, vasculitis
Dermatologic: Acne, allergic dermatitis, cutaneous and subcutaneous atrophy, dry scalp, edema, facial erythema, hyper or hypo-pigmentation, impaired wound healing, increased sweating, petechiae and ecchymoses, rash, sterile abscess, striae, suppressed reactions to skin tests, thin fragile skin, thinning scalp hair, urticaria
Endocrine: Abnormal fat deposits, decreased carbohydrate tolerance, development of Cushingoid state, hirsutism, manifestations of latent diabetes mellitus and increased requirements for insulin or oral hypoglycemic agents in diabetics, menstrual irregularities, moon facies, secondary adrenocortical and pituitary unresponsiveness (particularly in times of stress, as in trauma, surgery or illness), suppression of growth in children
Fluid and Electrolyte Disturbances: Fluid retention, potassium loss, hypertension, hypokalemic alkalosis, sodium retention
Gastrointestinal: Abdominal distention, elevation in serum liver enzymes levels (usually reversible upon discontinuation), hepatomegaly, hiccups, malaise, nausea, pancreatitis, peptic ulcer with possible perforation and hemorrhage, ulcerative esophagitis
General: Increased appetite and weight gain
Metabolic: Negative nitrogen balance due to protein catabolism
Musculoskeletal: Osteonecrosis of femoral and humeral heads, charcot-like arthropathy, loss of muscle mass, muscle weakness, osteoporosis, pathologic fracture of long bones, steroid myopathy, tendon rupture, vertebral compression fractures
Neurological: Arachnoiditis, convulsions, depression, emotional instability, euphoria, headache, increased intracranial pressure with papilledema (pseudo-tumor cerebri) usually following discontinuation of treatment, insomnia, meningitis, mood swings, neuritis, neuropathy, paraparesis/paraplegia, paresthesia, personality changes, sensory disturbances, vertigo
Ophthalmic: Exophthalmos, glaucoma, increased intraocular pressure, posterior subcapsular cataracts, and central serous chorioretinopathy
Reproductive: Alteration in motility and number of spermatozoa
Clinical Trials Experience
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.
The safety of RAYOS was evaluated in 375 rheumatoid arthritis patients in two controlled trials. Patients treated with RAYOS ranged in age from 20 to 80 years (median age 56 years), with 85% female, 99% Caucasian, 1% African-American, and < 1% Asian.
Patients received RAYOS 3 mg to 10 mg once daily at 10 pm; the majority (84%) received ≥ 5 mg. The clinical trial experience did not raise new safety concerns beyond those already established for immediate-release prednisone.
Postmarketing Experience
Adverse reactions have been identified during post approval use of RAYOS. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. The postmarketing experience has not raised new safety concerns beyond those already established for immediate-release prednisone.
Read the entire FDA prescribing information for Rayos (Prednisone Delayed-Release Tablets)
