Interventional Medications Used in Renal Scanning (1,2,7–12,14–16,21)
| Drug | Indication | Dose | Pharmacokinetics | Mechanism of action | Contraindications/cautions | Adverse effects/interactions |
| Furosemide | Diuretic challenge for obstructive uropathy on renal scan | 20–40 mg intravenously in adults and 1 mg/kg intravenously over 1–2 min in children | Onset, 5 min; peak, 15–30 min; half-life, 1.5–2 h; duration, 2–3 h; 99% plasma protein–bound | Loop diuretic that inhibits sodium, potassium, and chloride transport in ascending portion of loop of Henle | Contraindicated in anuria, sulfonamide hypersensitivity, and sodium or fluid depletion; caution in kidney or liver disease, diabetes, gout, lupus, pregnancy, and after urologic procedures | Tinnitus, allergic reaction, nausea, vomiting, dizziness, blurred vision, headache, hypotension, dehydration; potential interactions with aspirin, diuretics, digoxin, lithium, antihypertensives, and NSAIDs |
| Captopril | Renal artery stenosis in renovascular hypertension renal scan | 25–50 mg tablet orally 60 min before renal scan | Onset, 15 min; peak, 45–70 min; half-life, 2–3 h; duration, 6–12 h; 30% plasma protein–bound | Blocks conversion of angiotensin I to II, blocking blood pressure compensation and reducing glomerular filtration | Contraindicated in angioedema, high renin levels, dehydration, salt depletion, recent dialysis, aortic stenosis, pregnancy, and hypersensitivity; caution in scleroderma, lupus, depression, diabetes, liver dysfunction, peripheral vascular disease, and dialysis | Hypotension, dizziness, tachycardia, chest pain, loss of taste, fever, and rash; can cause dry cough; potential interactions with other ACE inhibitors or ARBs, diuretics, hypertensives, NSAIDs, digoxin, and lithium |
| Enalapril | As above | Oral dose, 20–40 mg; 0.04 mg/kg in 10 mL of saline intravenously over 3–5 min to maximum dose of 2.5 mg | Onset, 60 min; peak, 4–6 h; half-life, 11 h; duration, 24 h; 50%–60% plasma protein–bound; if given intravenously, onset is 15 min and peak effect is at 1 h | As for captopril except is ester prodrug converted to enalaprilat in liver after absorption | As above | As above |
Duration is period of significant or measurable effect. Some adverse effects are more likely when used therapeutically than in single interventional doses.