Drug Guide
Technetium Tc-99m Tetrofosmin
Classification
Therapeutic: Diagnostic radiopharmaceutical agent for myocardial perfusion imaging
Pharmacological: Radiotracer for nuclear medicine imaging
FDA Approved Indications
- Myocardial perfusion imaging to evaluate patients with known or suspected coronary artery disease
Mechanism of Action
emits gamma radiation detectable by a gamma camera as it accumulates in the myocardium, allowing assessment of myocardial blood flow and viability.
Dosage and Administration
Adult: Typically 10-30 mCi (370-1110 MBq) intravenously, adjusted based on clinical protocol.
Pediatric: Use is not well established; consult specialized guidelines.
Geriatric: Dose adjustments are generally not necessary but should consider renal function and overall health.
Renal Impairment: Adjustment may be needed; caution advised.
Hepatic Impairment: No specific adjustment required.
Pharmacokinetics
Absorption: Injected intravenously; rapid distribution.
Distribution: Primarily myocardial uptake with initial blood pool activity.
Metabolism: Not significantly metabolized; remains as Tc-99m tetrofosmin.
Excretion: Renal clearance is predominant.
Half Life: Approximately 6 hours for Tc-99m radionuclide; biological half-life depends on tissue uptake.
Contraindications
- Hypersensitivity to technetium or its components.
Precautions
- Use with caution in pregnant or breastfeeding women; consult with healthcare provider.
Adverse Reactions - Common
- Pain or discomfort at injection site (Rare)
- Nausea or headache (Rare)
Adverse Reactions - Serious
- Allergic reactions including rash, difficulty breathing (Very rare)
- Radiation exposure with potential for adverse effects (Depends on dose and exposure)
Drug-Drug Interactions
- None specific; caution with other radiopharmaceuticals or radiotherapy.
Drug-Food Interactions
- None established
Drug-Herb Interactions
- None established
Nursing Implications
Assessment: Ensure proper patient identification, verify absence of contraindications, assess renal function.
Diagnoses:
- Impaired tissue perfusion related to myocardial ischemia.
Implementation: Administer VIA injection as per protocol; monitor for allergic reactions.
Evaluation: Assess imaging results for myocardial perfusion patterns and abnormalities.
Patient/Family Teaching
- Explain the procedure, purpose, and radiation safety precautions.
- Advise on the importance of remaining still during imaging.
Special Considerations
Black Box Warnings:
- None specifically for this agent.
Genetic Factors: None specified.
Lab Test Interference: Radiopharmaceuticals can interfere with certain blood tests temporarily.
Overdose Management
Signs/Symptoms: Overexposure to radiation, local injection site reactions.
Treatment: Supportive care; no specific antidote; discontinue use and provide symptomatic treatment.
Storage and Handling
Storage: Store lyophilized kit at recommended temperatures (2-8°C).
Stability: Refer to manufacturer's instructions; generally stable until expiration date when stored properly.