oxymetholone

Action and Spectrum

Oxymetholone is a synthetic anabolic-androgenic steroid derived from testosterone. Its primary action involves stimulating protein synthesis and muscle growth by activating androgen receptors in target tissues. Once inside the cell, oxymetholone or its active metabolites bind to these receptors, forming a complex that moves into the cell nucleus. There, it interacts with specific DNA sequences known as hormone response elements, regulating the expression of genes responsible for anabolic effects. Additionally, some of its actions may occur through its conversion to dihydrotestosterone (DHT) or estradiol, which further modulate androgenic and estrogenic pathways. 

Drug Interaction

Adverse Reaction

Frequency undefined: 

Depression 

Excitation 

Habituation 

Insomnia 

Acne 

Gynecomastia 

Change in libido 

Diarrhea 

Nausea 

Vomiting 

Electrolyte & water retention 

Decreased glucose tolerance 

Increased LDL 

Decreased HDL 

Cholestatic jaundice 

Muscle cramps 

Increased serum CPK 

Black Box Warning

Use of anabolic-androgenic steroids has been linked to peliosis hepatis, a condition where the liver (and sometimes the spleen) develops blood-filled cysts that can go unnoticed until severe liver failure or internal bleeding occurs; stopping the steroid often leads to resolution. Liver cell tumors, usually benign and hormone-dependent but sometimes malignant, have also been reported. These tumors can regress or stop growing once the steroid is discontinued but can remain undetected until they cause dangerous internal bleeding due to their high vascularity. 

In addition, anabolic steroids may significantly alter blood lipid levels by lowering HDL and sometimes raising LDL cholesterol, which can increase the risk of atherosclerosis and coronary artery disease. 

Contraindication / Caution

Contraindications 

Anabolic-androgenic steroids should not be used in males with known or suspected prostate or breast cancer, or in females with breast cancer accompanied by high blood calcium levels. They are also contraindicated in women who are pregnant or may become pregnant. Use is not advised in patients with nephrotic conditions, significant liver impairment, or known hypersensitivity to the drug. 

Cautions 

Anabolic-androgenic steroids can cause serious liver problems, including benign or malignant tumors, and may accelerate bone growth in children, affecting final height. They can lead to cholestatic hepatitis and jaundice even at low doses; stopping treatment usually reverses this, but continued use may cause liver failure or coma, so liver function should be monitored regularly. 

In breast cancer patients, these drugs can raise blood calcium levels by increasing bone breakdown. They may also cause fluid retention and worsen heart, kidney, or liver conditions, especially if combined with adrenal steroids, though this can often be managed with diuretics. 

Older men face a higher risk of prostate enlargement or cancer, while women may develop signs of masculinization (such as deep voice, hair growth, or enlarged clitoris), which may become permanent if treatment isn’t stopped early. Menstrual cycle changes are also possible. 

Diabetics may need to adjust their diabetes medication, and these steroids can affect blood clotting factors, which might increase bleeding risk. 

Pregnancy / Lactation

Pregnancy consideration:  

Category X 

Breastfeeding warnings:  

Not recommended as excretion of the drug in breastmilk is unknown 

Pregnancy category: 

• Category A: Satisfactory and well-controlled studies show no risk to the fetus in the first or later trimester. 

• Category B: No evidence shown of risk to the fetus found in animal reproduction studies, and there are not enough studies on pregnant women    

• Category C: Adverse effects on the fetus found with evidence in animal reproduction studies and no adequate evidence for a product in humans; Pregnant women must take care of the potential risks. 

• Category D: There is adequate data available with sufficient evidence of human fetal risk from various platforms. However, despite potential dangers may be used only in emergency cases for potential benefits. 

• Category X: Drugs listed in this category outweigh risks over benefits. The drug is not for pregnant women. 

• Category N: No data is available for the drug under this category. 

Pharmacology

 Pharmacology 

Oxymetholone is a synthetic androgen derived from dihydrotestosterone, chemically modified with a hydroxymethylidene group and a 17-alpha methyl group. It was primarily used to treat certain types of anemia but has largely been replaced by safer alternatives due to its side effect profile. 

Pharmacodynamics 

Oxymetholone is a potent anabolic-androgenic steroid that promotes protein synthesis and increases red blood cell production. Its primary effect is to stimulate the growth of muscle tissue and bone marrow activity by binding to androgen receptors in target tissues. This enhances nitrogen retention, leading to an increase in muscle mass and strength. Oxymetholone also stimulates erythropoiesis by boosting the production of erythropoietin, which helps treat certain forms of anemia. 

Pharmacokinetics 

Absorption 

Oxymetholone is well absorbed when taken orally, thanks to its 17α-alkylation, which allows it to survive first-pass liver metabolism. 

Distribution 

It is widely distributed throughout the body, binding moderately to plasma proteins. 

Metabolism 

Oxymetholone is metabolized primarily in the liver. Its structural modifications slow hepatic breakdown, contributing to its potent anabolic effects but also its risk for hepatotoxicity. 

Elimination/Excretion 

The drug and its metabolites are mainly excreted through the urine. Its elimination half-life is variable but generally ranges from 8 to 9 hours. 

Adminstartion

Oxymetholone is taken orally, usually in tablet form, and is typically dosed once or twice daily depending on the condition being treated. It should be used at the lowest effective dose for the shortest duration necessary to minimize the risk of side effects. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: oxymetholone 

Pronounced: Oxy-meth-o-lone 

Why do we use oxymetholone? 

Oxymetholone is mainly prescribed to treat certain types of anemia by boosting red blood cell production. It has also been used in the management of osteoporosis and to promote weight gain and muscle growth in patients who are malnourished or have underdeveloped muscle mass.