Domain III(E): understand indications, contraindications, & administration of interventional & adjunct pharmaceutical agents

Dipyridamole (Persantine®) indications

- used as a pharmacologic stress agent for myocardial perfusion studies

- works to increase coronary blood flow within the heart

Dipyridamole (Persantine®) contraindications

- asthmatics with ongoing wheezing

- greater than 1st degree AV block

- systolic BP >90 mmHg

- use of dipyridamole or xanthine meds in 24 hours or caffeine in food for 12 hours

- profound sinus bradycardia <40 mmHg

- known hypersensitivity to adenosine or dipyridamole

- unstable acute myocardial infarction

Dipyridamole (Persantine®) administration

- IV

- 0.56 mg/kg over 4 minutes

- inject tracer at 7-9 minute mark

Adenosine indications

- used as a pharmacologic stress agent for myocardial perfusion studies

- works to increase coronary blood flow within heart

- increases endogenous levels of adenosine in the body

Adenosine contraindications

- asthmatics with ongoing wheezing

- greater than 1st degree AV block

- systolic BP < 90 mmHg

- use of dipyridamole or xanthine meds in 24 hours or caffeine in food for 12 hours

- profound sinus bradycardia <40 BPM

- known hypersensitivity to adenosine or dipyridamole

- unstable acute myocardial infarction

Adenosine administration

- IV

- 0.14 mg/kg/min for 6 minutes

- inject tracer at 3 minute mark

Dobutamine indications

- used to reverse any lingering symptoms from a pharmacologic stress test

- secondary pharmacologic stressor (vasodilator agents are primary stressors)

- used more extensively in echocardiograms

Dobutamine contraindications

- recent (< 1 week) MI

- unstable angina

- severe aortic stenosis / LV outflow tract obstruction

- uncontrolled hypertension (<200/110 mmHg)

- aortic dissection or large aortic aneurysm

- history of ventricular tachycardia

- patient on beta blockers

Dobutamine administration

- IV

- start infusion at 5 or 10 ucg/kg/min

- increase every 3 minutes (5, 10, 20, 30, 40) with maximum dose of 40 ucg/kg/min

- inject tracer at 1 minute into highest dobutamine dose & continue dobutamine infusion for remaining 2 minutes

Regadenoson (Lexiscan®) indications

- used as a pharmacologic stress agent for myocardial perfusion studies

- work to increase coronary blood flow within heart

- increase endogenous levels of adenosine in the body

Regadenoson (Lexiscan®) contraindications

- asthmatics with ongoing wheezing

- greater than 1st degree AV block

- systolic BP < 90 mmHg

- use of dipyridamole or xanthine meds in 24 hours or caffeine in food for 12 hours

- profound sinus bradycardia

- known hypersensitivity to adenosine or dipyridamole

- unstable acute myocardial infarction

Regadenoson (Lexiscan®) administration

- IV

- 0.4 mg bolus over 5-10 seconds

- inject tracer 20 seconds later

Captopril indications

- RVH (renovascular hypertension imaging)

- used to help determine if high blood pressure is due to reduced perfusion in the kidneys

Captopril contraindications

- known hypersensitivity to captopril or other ACE inhibitors

- history of angioedema related to previous ACE inhibitor use

- bilateral renal artery stenosis or stenosis in solitary functioning kidney (risk of acute renal failure)

severe hypotension or dehydration

- hyperkalemia

- pregnancy

Captopril administration

- 50 mg crushed tablet PO with water (up to 1L)

- administered 60 minutes before radiopharmaceutical

- monitor blood pressure before & after administration

Enalaprilat indications

- RVH (renovascular hypertension) imaging

- alternative to oral captopril

Enalaprilat contraindications

- hypersensitivity to enalapril or other ACE inhibitors

- bilateral renal artery stenosis or solitary kidney with stenosis

- severe hypotension or dehydration

- hyperkalemia

- aortic stenosis (can reduce perfusion further)

- pregnancy

Enalaprilat administration

- IV

- 0.04 mg/kg with maximum of 2.5 mg

- administered over 5 minutes, 15 minutes after enaliprat dose

Furosemide (Lasix®) indications

- used in diuretic renal imaging to evaluate for urinary tract obstruction

- helps differentiate between dilated but non-obstructed collecting systems & true obstructive uropathy

Furosemide (Lasix®) contraindications

- sulfa allergy

- severe dehydration or hypovolemia

- hypotension

- severe electrolyte imbalances

- anuria (no urine production)

- known hypersensitivity to furosemide

Furosemide (Lasix®) administration

- IV injection

- usually given over 1-2 minutes

- can be given 15 minutes prior, 20 minutes prior, or simultaneously with radiopharmaceutical

- ensure patient has voided bladder before imaging & is positioned supine

Insulin indications

- PET FDG imaging in diabetic patients

- ensures optimal tumor-to-background contrast by lowering serum glucose & minimizing FDG uptake in muscles

Insulin contraindications

- hypoglycemia

- non-diabetic patients

- patients who have not eaten recently

Insulin administration

- subcutaneous (most common)

- IV (hospital setting)

- imaging typically delayed for ~4 hours to allow insulin levels to drop

Acetazolamide (Diamox®) indications

- given to increase sensitivity for ischemia in brain perfusion studies with Tc-99m ECD (bicistate) or Tc-99m HMPAO (exametazime)

- induces vasodilation & increases blood flow in the brain to identify areas with impaired reserve

Acetazolamide (Diamox®) contraindications

- sulfa allergies

- active TIA (transient ischemic attack) syndrome or stroke

- severe hepatic or renal dysfunction

- electrolyte imbalances

Acetazolamide (Diamox®) administration

- IV

- typical dose: 1g over 2 minutes, administered 15-20 minutes prior to radiopharmaceutical injection

Cholecystokinin/sincalide/CCK indications

- hepatobiliary imaging

- causes gallbladder to contract (similar to fatty meal)

- used to rule out obstruction (avoid false positive) & to calculate GBEF

- can be used as a pretreatment in those who have been fasting for more than 24 hours

Cholecystokinin/sincalide/CCK contraindications

- pregnancy / nursing

- known allergy or hypersensitivity to CCK or sincalide

Cholecystokinin/sincalide/CCK administration

- IV

- 0.01 - 0.02 ug/kg body weight given over 1 - 3 minutes

- can cause spasm & contraction of other smooth muscle (GI tract) if given too fast

Morphine indications

- hepatobiliary imaging

- distinguishes chronic cholecystitis from acute cholecystitis

- increases intrabiliary pressure by contracting sphincter of Oddi

- delays or inhibits gallbladder emptying

Morphine contraindications

- morphine allergy

- acute pancreatitis

- respiratory depression

Morphine administration

- IV

- 0.04 mg/kg over 3 minutes

Cimetidine/famotidine indications

- histamine (H2) blockers given to improve sensitivity of Tc04- Meckel's diverticulum scan

- inhibits gastric secretion & reduce pertechnetate release from gastric mucosa

- reduce stomach acid production so that the diverticulum can be identified easily

- results in increased sensitivity & target-to-background ratio for detecting ectopic gastric mucosa

Cimetidine/famotidine contraindications

- known allergy or sensitivity to cimetidine or famotidine

- severe renal or hepatic impairment

- drug interactions with warfarin, theophylline, phenytoin

- pregnancy / nursing

Cimetidine/famotidine administration

- PO 2 days prior (dose: 300 mg cimetidine 3-4x/day)

- IV 1 hour prior (dose: 300 mg cimetidine infused over 15-30 minutes)

ACD solution (acid citrate dextrose) indications

- any Tc-99m RBC labeling (GI bleeds, MUGAS)

- anticoagulant: prevents blood from clotting during in vitro or modified in vivo labeling of RBCs

ACD solution (acid citrate dextrose) contraindications

- allergy or hypersensitivity to ACD (rare)

- severe anemia

- hypocalcemia (citrate can chelate calcium)

- volume-sensitive conditions (pediatric or frail patients: small volume blood draws)

ACD solution (acid citrate dextrose) administration

- mixed with patient blood during blood draw

- typical ratio: 1 part ACD to 5 parts blood

Heparin indications

- any Tc-99m RBC labeling (GI bleeds, MUGAs)

- prevents clotting when handling or labeling blood products outside body

Heparin contraindications

- known hypersensitivity to heparin or heparin-induced thrombocytopenia (HIT)

- active bleeding or high risk for bleeding disorders

- severe hypertension

- liver disease

- recent surgery

Heparin administration

- added to syringe or collection vial used for drawing blood

Contrast media (oral & IV) indications

- used in radiology studies to enhance anatomical detail

- of concern with thyroid uptake studies so that results are not falsely misinterpreted

- contains free iodine, which competes with radiotracers for thyroid uptake

Contrast media (oral & IV) contraindications

- thyroid uptake studies

- blocks absorption of thyroid meds & should be avoided to prevent inaccurate results

- typically, a 4-6 week waiting period is recommended before thyroid uptake testing

Contrast media (oral & IV) administration

- PO: for GI imaging enhancement in CT

- IV: for vasculature or soft tissue enhancement

Lugol's solution/SSKI indication

used in iodine isotope studies where the thyroid is not the target organ (I-123 DatScan or ioflupane, I-123 MIBG (Andreview), I-125 iothalamate)

Lugol's solution/SSKI contraindications

- use of another type of thyroid blocking agent that will interfere with Lugol's solution

- allergy or sensitivity to iodine

Lugol's solution/SSKI administration

- oral

- typically administered ~1 hour prior to radiopharmaceutical injection

Thyroid Stimulating Hormone (TSH) indications

thyroid cancer follow-up imaging or treatment in patients who:

- cannot discontinue thyroid hormone therapy

- require simulation of residual thyroid tissue or metastases for better uptake of radioiodine

- helps elevate endogenous TSH levels without needing to stop levothyroxine (Synthroid®)

Thyroid Stimulating Hormone (TSH) contraindications

- known hypersensitivity to thyrotropin alfa or any component of the formulation

- adrenal insufficiency

- cardiovascular disease (can transiently increase tumor size due to stimulation)

- large metastatic tumors (may cause swelling or pain from stimulation)

Thyroid Stimulating Hormone (TSH) administration

- intramuscular (IM)

- 2 injections 24 hours apart (0.9mg per injection)

- radioiodine administration 24 hours after 2nd injection

- ensure thyroid hormone therapy is continued during thyrogen protocol

Lidocaine indications

numbing of injection site to reduce pain

Lidocaine contraindications

- allergies to lidocaine

- severe liver disease

- heart block without pacemaker

Lidocaine administration

- injection, topical, cream, spray inhaled

- onset of action is rapid: typically within 30 sec - 2 min

Lidocaine (EMLA®) cream indication

numbing of site injection to reduce pain

Lidocaine (EMLA®) cream contraindication

allergies to lidocaine

Lidocaine (EMLA®) cream administration

topical

Atropine indications

- used in conjunction with dobutamine chemical MPI stress test

- increases heart rate to help patient reach their necessary heart rate

Atropine contraindications

- glaucoma

- myasthenia gravis

- obstructive uropathy or GI tract obstruction

- known hypersensitivity to atropine or belladonna alkaloids

- elderly

- cardiovascular disease

Atropine administration

- IV push (small, incremental doses)

- typically 0.25 - 1 mg per dose

- maximum total dose: 1-2 mg

Recombinant human TSH (Thyrogen®) indications

- used in patients with thyroid cancer who are undergoing follow-up scans or treatment with radioactive iodine (RAI)

- these patients need elevated TSH levels to make any remaining thyroid tissue or cancer cells absorb iodine

- allows TSH levels to rise without stopping thyroid hormone therapy

- helps to identify residual thyroid tissue & metastatic thyroid cancer cells

Recombinant human TSH (Thyrogen®) contraindications

- patients with heart conditions

- can temporarily increase thyroid hormone levels, which may affect the heart

Recombinant human TSH (Thyrogen®) administration

- IM (intramuscularly)

- given prior to thyroid study so all iodine avid cells can be located

- usually given in 2 doses over 2 consecutive days, with RAI administration or scan on 3rd day

Amino acids (lysarg) indications

Amino acids (lysarg) indications

- protect kidneys from radiation damage for Lu-177 Lutathera therapy administration

- reduces tubular reabsorption

Amino acids (lysarg) contraindications

- severe hyperkalemia

- pre-existing metabolic acidosis

- known hypersensitivity to amino acid solutions

- cardiac, hepatic, renal impairment (fluid overload risks)

Amino acids (lysarg) administration

- IV infused over 4 hours

- typically 30 minutes prior to administration of Lu-177

- accompanied by antiemetic pre-treatment

Zofran/ement indications

- anti nausea/emetic medication

- give before radiopharmaceutical therapies (Lu-177 or Y-90)

Zofran/ement contraindications

- known hypersensitivity

- concurrent use with certain serotonergic drugs (may increase risk of serotonin syndrome)

- QT prolongation

- electrolyte imbalances

- hepatic impairment

Zofran/ement administration

- Zofran (ondansetron): PO, IM, IV, given 30 mins before therapy or procedure

- Emend (aprepitant): PO, IV, multi-drug antiemetic regimen for delayed nause

Beta blockers (Metoprolol) indication

reduce heart rate & lower blood pressure by blocking effects of adrenaline (epinephrine) on beta receptors in the heart

Beta blockers (Metoprolol) contraindication

bruce protocol patients (blunt the heart rate response, making it difficult for patients to reach their target heart rate & accurately reflect presence or severity of ischemia during peak exertion

Beta blockers (Metoprolol) administration

- oral (daily use)

- IV

- ophthalmic (used for glaucoma)

Boost®/Ensure® indication

hepatobiliary imaging (used to cause gallbladder to contract, simulating digestion of fatty meal)

Boost®/Ensure® contraindications

- lactose intolerance or milk protein allergy

- severe fat malabsorption disorders

- diabetes (sugar content)

Boost®/Ensure® administration

- after tracer injection, followed by imaging 30-60 minutes later

- dose: 8oz bottle