strontium 89 chloride

Action and Spectrum

Actions and Spectrum: 

Actions: 

strontium-89 chloride is a beta-emitting radiopharmaceutical. When administered to a patient, it selectively targets and accumulates in areas of active bone formation, such as sites affected by bone metastases. The beta particles emitted by the strontium-89 chloride penetrate the surrounding bone tissue, delivering localized radiation therapy to the cancerous areas. 

Spectrum: 

The radioactive decay of strontium-89 chloride produces beta particles. Beta particles are high-energy electrons or positrons that are emitted during the process of radioactive decay. The energy spectrum of the beta particles emitted by strontium-89 chloride ranges from a few kilo electronvolts (keV) up to a maximum energy of approximately 1.463 megaelectronvolts (MeV). 

Drug Interaction

Adverse Reaction

Frequency not defined 

Transient increase in bone pain 

Chills/fever 

Flushing after rapid injection 

Hot flush 

Septicemia 

Bone marrow toxicity 

Renal impairment 

Thrombocytopenia 

Black Box Warning

Black Box Warning: 

None 

Contraindication / Caution

Contraindication/Caution: 

• Pregnancy 
• Breastfeeding 
• Severe bone marrow suppression 
• Severe renal impairment 
• Pre-existing skeletal anomalies 
• Age 
• General health status 

Pregnancy / Lactation

Pregnancy consideration:  

Category D 

Breastfeeding warnings:  

The drug is excreted in breast milk.  

Pregnancy category: 

• Category A: well-controlled and Satisfactory studies show no risk to the fetus in the first or later trimester. 
• Category B: there was no evidence of risk to the fetus in animal studies, and there were not enough studies on pregnant women. 
• Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.    
• Category D: adequate data with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.    
• Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women. 
• Category N: There is no data available for the drug under this category 

Pharmacology

Pharmacology: 

strontium chloride-89 is a calcium analog that behaves similarly to calcium in the body. It is taken up by osteoblastic cells in the bone, particularly in areas of increased bone turnover, such as metastatic cancer sites. The radioactive emissions from Sr-89, specifically beta particles, damage the DNA of nearby cancer cells, leading to their destruction.  

Pharmacodynamics: 

• Activation or inhibition of receptors: Drugs can mimic the actions of endogenous molecules (agonists) or block their actions (antagonists) by binding to and activating or inhibiting specific receptors. 
• Enzyme inhibition: Drugs can inhibit specific enzymes involved in biochemical pathways, thereby altering the production or metabolism of specific molecules in the body. 
• Ion channel modulation: Drugs can affect the function of ion channels, which are proteins that control the flow of ions across cell membranes. By modulating ion channels, drugs can influence electrical signals and cellular excitability. 
• Altered gene expression: Certain drugs can interact with DNA or other cellular components to influence gene expression and protein synthesis. 

Pharmacokinetics: 

Absorption 

The drug is absorbed systemically. 

Distribution  

After intravenous administration, strontium chloride-89 rapidly distributes throughout the body and selectively accumulates in bone tissue.  

Metabolism 

It doesn’t get metabolized in the body and is excreted through the urine over several days, with most of the radioactivity being excreted within the first 48 hours. 

Elimination and Excretion 

It has a long physical half-life of approximately 50.5 days, allowing for sustained radiation therapy. The elimination of strontium chloride-89 occurs mainly through the feces, with minimal renal excretion. 

Adminstartion

Administration: 

strontium chloride-89 is administered as an intravenous injection. A healthcare professional needs to insert the needle into a vein, typically in the arm, and slowly inject the medication into the bloodstream. The injection process usually takes a few minutes. 

After the injection, the patient is monitored briefly to ensure no immediate adverse reactions or complications. Check the vital signs, such as heart rate and blood pressure be periodically. Patients are typically instructed to report any discomfort or adverse effects they experience during this period. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: strontium 89 chloride 

Pronounced: STRON-shee-um-KLOR-ide-Sr-89 

Why do we use strontium 89 chloride? 

strontium chloride-89 (Sr-89) is used in nuclear medicine to treat bone metastases. It helps relieve pain, palliative care, selective targeting, and sustained radiation. 

It’s important to note that strontium chloride-89 is typically considered when other treatment options, such as analgesic medications or radiation therapy, have not provided sufficient pain relief.