Off-Label Drug Use

Off-Label Clinical Use of Drugs

• The FDA approves drugs for specific health conditions, but doctors often prescribe them for off-label use, which accounts for around 20% of all prescriptions in the US.
• Off-label use can be safe and effective, but it also carries certain risks.

Dexamethasone

• Used off-label during pregnancy to treat congenital adrenal hyperplasia (CAH) in female babies.
• Accelerates fetal lung maturation, decreases respiratory distress syndrome, and improves survival in preterm neonates.

Thiazide

• Used off-label to treat osteoporosis.

Metformin

• Used off-label for weight loss and breast cancer treatment.

Silymarin

• Used off-label as a liver supplement and iron chelating agent in thalassemia.
• Decreases oxidative stress and frequency of blood transfusions.

Salbutamol

• On-label use: Relieves symptoms of asthma and chronic obstructive pulmonary disease (COPD).
• Off-label use: Second-line management in treating hyperkalemia.
• Mechanism of action: Reduces serum potassium levels by increasing the shift of extracellular potassium into the intracellular space.

Lactulose

• On-label use: Treats constipation.
• Off-label use: Treats hepatic coma.
• Mechanism of action:
  • On-label: Not absorbed in the small intestine, broken down in the colon, and increases fecal bulk, leading to bowel movements.
  • Off-label: Acidifies colonic contents, converting ammonia to its ionized form, which is less readily absorbed, reducing blood ammonia levels and improving neurological symptoms.

Domperidone (Motilium)

• On-label use: Treats nausea, vomiting, indigestion, and gastric reflux.
• Off-label use: Increases milk supply in lactating women.
• Mechanism of action: Stimulates gastric muscle contraction, releasing prolactin, which stimulates breast milk production.

Colchicine

• On-label use: Treats and prevents gout.
• Off-label use: Treats acute pericarditis, preventing recurrent episodes, and other conditions like actinic keratosis, amyloidosis, Peyronie's disease, and psoriasis.
• Mechanism of action: Inhibits microtubule self-assembly, decreasing leucocyte motility and phagocytosis.

Spironolactone

• On-label use: Treats heart failure, hypertension, and hypokalemia.
• Off-label use: Treats acne vulgaris and hirsutism in female patients.
• Mechanism of action: Affects androgen receptors in the sebaceous glands, reducing sebum production, and blocks the conversion of weaker androgens to more potent androgens in peripheral tissues.

Viagra (Sildenafil)

• On-label use: Treats erectile dysfunction.
• Off-label use: Treats high-altitude pulmonary edema (HAPE).
• Mechanism of action: Dilates blood vessels in the lungs, improving oxygenation.

Warfarin

• On-label use: Treats and prevents hypercholesteremia, atherosclerosis, and reduces the risk of heart disease and stroke.
• Off-label use: Treats certain types of cancer.

Azathioprine

• On-label use: Prevents kidney transplant rejection.
• Off-label use: Treats inflammatory bowel disease, active rheumatoid arthritis, multiple sclerosis, myasthenia gravis, and autoimmune hepatitis.
• Mechanism of action: Inhibits purine synthesis, disrupting DNA function and triggering cell death.

Statin

• On-label use: Treats and prevents hypercholesteremia, atherosclerosis, and reduces the risk of heart disease and stroke.
• Off-label use: Treats certain types of cancer, neurological diseases like Alzheimer's and Parkinson's, and autoimmune diseases like HIV and tuberculosis.

Propranolol

• On-label use: Treats hypertension, angina, arrhythmias, and anxiety.
• Off-label use: Treats essential tremor, ventricular fibrillation, and pulseless ventricular tachycardia.

Semaglutide (Wegovy)

• On-label use: Treats type 2 diabetes.
• Off-label use: Treats obesity.
• Mechanism of action: Increases insulin secretion and reduces glucagon secretion, mimicking the effects of glucagon-like peptide-1.

Adrenaline

• On-label use: Treats type 1 hypersensitivity reactions, including anaphylaxis, acute asthmatic attacks, and symptomatic bradycardia.
• Off-label use: Treats ventricular fibrillation, pulseless ventricular tachycardia, cardiac arrest, and pulseless electrical activity.

Aspirin (Antiplatlets)

• On-label use: Treats pain, fever, rheumatic disease, coronary syndrome, cerebrovascular disease, and angina.
• Off-label use: Treats preeclampsia in gynecology and obstetrics outpatients.
• Mechanism of action: Inhibits the activity of cyclooxygenase, leading to the formation of prostaglandins that cause inflammation, swelling, pain, and fever.

Quetiapine (Atrolak, Sondate)

• On-label use: Treats schizophrenia, bipolar disorder, and major depressive disorder.
• Off-label use: Treats insomnia.
• Mechanism of action: Antagonizes the D2 receptor in the mesolimbic pathway, relieving positive symptoms, and antagonizes 5HT2A receptors, relieving negative symptoms of schizophrenia.