How Do Radiopharmaceuticals Work?

Radiopharmaceuticals are a class of drugs used to treat metastatic pheochromocytoma (a small vascular tumor of the adrenal gland), paraganglioma (rare tumors that form near the carotid artery, along nerve pathways in the head and neck), and neuroendocrine tumors, to relieve pain in patients with osteoblastic metastatic bone lesions, and as a diagnostic agent in the uptake test to evaluate thyroid function and thyroid malignancies and for lymphatic mapping to locate lymph nodes draining a primary tumor site in patients with solid tumors.

Radiopharmaceuticals are drugs that contain radioactive isotopes, which are bound to biological molecules that can target specific organs, tissues, or cells within the human body and are used for diagnostic and therapeutic purposes. They emit radiation that involves targeting tumors with molecules carrying radioactive particles that bind to specific receptors expressed by the tumor.

Radiopharmaceuticals are used to produce images of organs or tissues, a process called “scintigraphy.” A type of medical device known as a gamma camera can detect the gamma rays emitted by the radioisotope and generate images in a noninvasive manner that reflect the function of the organ or tissue under investigation.

Radiopharmaceuticals are also known as radiotracers, as they are used to diagnose dysfunction in body tissues.

Radiopharmaceuticals are administered via injectable and oral routes.

Radiopharmaceuticals are used in conditions such as:

• Pheochromocytoma (a small vascular tumor of the adrenal gland)
• Paraganglioma (rare tumors that form near the carotid artery, along nerve pathways in the head and neck)
• Hyperthyroidism (overactive thyroid)
• Thyroid cancer
• Thyroid function diagnostic
• Neuroendocrine tumors (cancers that begin in specialized cells called neuroendocrine cells)
• Lymphatic mapping and node biopsy
• Bone pain from skeletal metastases
• Prostate cancer

Some of the common side effects include:

• Nausea
• Vomiting
• Constipation
• Abdominal pain
• Headache
• Diarrhea
• Decreased appetite
• Back pain
• Tiredness/weakness
• Dry mouth
• Dysgeusia (an altered sense of taste)
• Flushing

Other rare side effects include:

• Dizziness 
• Fatigue 
• Anemia (low red blood cell count)
• Thrombocytopenia (low blood platelet count)
• Weight loss
• Alopecia (unpredictable, patchy hair loss)
• Tachycardia (a heart rate over 100 beats per minute)
• Cough
• Dyspnea (shortness of breath)
• Rash/hives/itching
• Hyperhidrosis (abnormally excessive sweating)
• Increased creatinine (a waste product from the normal wear and tear of muscles in the body)
• Hyperglycemia (high blood glucose level)
• Hyperuricemia (an elevated uric acid level in the blood)
• Hypocalcemia (low blood glucose level)
• Increased liver enzymes
• Peripheral edema (swelling of lower legs or hands)
• Septicemia (a serious and life-threatening bloodstream infection)

Information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with your doctor or pharmacist to make sure these drugs do not cause any harm when you take them along with other medicines. Never stop taking your medication and never change your dose or frequency without consulting your doctor.

Generic and brand names of radiopharmaceuticals include:

• Azedra
• Hicon
• Iobenguane I 131
• Lutathera
• Lutetium Lu 177-dota-tate
• Lymphoseek
• Metastron
• Quadramet
• Radium-223 dichloride
• Samarium sm 153 lexidronam
• Sodium iodide I-131
• Strontium 89 chloride
• Technetium Tc 99m tilmanocept
• Xofigo