TABLE 1

Other Less Commonly Used Interventional Medications (5–7,10,11,15–20,23)

Drug	Indication	Dose	Pharmacokinetics	Mechanism of action	Contraindications/cautions	Adverse effects/interactions
Acetazolamide	Cerebral flow reserve in brain perfusion studies	1 g diluted in sterile water intravenously over 2 min	Onset, 30 min, slow; peak, 2 h; duration, 12 h; half-life, 3–6 h; 70%–90% plasma protein–bound	Carbonic anhydrase inhibitor; causes sodium bicarbonate dieresis and vasodilation in brain in response to cerebral carbonic acidosis (carbon dioxide clearance inhibition)	Contraindicated in sodium or potassium depletion, hyperchloremic acidosis, Addison disease, closed-angle glaucoma, and severe renal or liver dysfunction; caution in acute stroke, kidney or liver disease, diabetes, gout, lupus, hypotension, and pregnancy	Tingling sensation, flushing, dizziness, blurred vision, confusion, nausea, headache, tinnitus, and allergic reaction; potential interactions with aspirin, lithium, cyclosporin, amphetamines, other diuretics, antihypertensives, salicylates, hypoglycemics, phenytoin, sodium bicarbonate, anticoagulants, and cardiac glycosides
Cimetidine	Enhanced detection of Meckel diverticulum	300 mg orally, 4 times over 24 h in adults and 20 mg/kg in 20 mL of saline intravenously over 20 min in children	Onset, 0.5–1 h; peak, 1 h; half-life, 2 h; duration, 4–6 h; 20% plasma protein–bound	H₂ histamine receptor blocker; reduces gastric acid secretion and volume and impedes ^99mTc-pertechnetate secretion	Contraindicated in known hypersensitivity; caution in renal or cardiovascular dysfunction	Headache, dizziness, diarrhea, muscle pain, confusion, and bradycardia; potential interactions with medications metabolized in liver; can also alter bioavailability of drugs reliant on stomach pH for absorption
Ranitidine	As above	300 mg orally for adults and 1 mg/kg intravenously over 20 min for children	Onset, 60 min; peak, 2–3 h; half-life, 2–3 h; duration, 4–13 h; 15% plasma protein–bound	As above	As above	As above
Omeprazole		40 mg orally morning before and morning of scan	Onset, 60 min; peak, 2 h; half-life, 0.5 h; duration, 3–5 d; 95% plasma protein–bound	Proton pump inhibitor (irreversible); suppresses stomach acid secretion and impedes ^99mTc-pertechnetate secretion	Contraindicated in known hypersensitivity; caution in liver dysfunction; ranitidine is preferred in pediatrics	Infrequent but include headache, dizziness, abdominal pain, diarrhea, nausea, vomiting, and rash; potential interactions with diazepam, phenytoin, warfarin, and medications reliant on gastric acidity for absorption

Duration is period of significant or measurable effect. Some adverse effects are more likely when used therapeutically than in single interventional doses.