Adjunctive Medications Commonly Used in Nuclear Cardiology (712,1517)

Drug/indication/dosePharmacokinetics/mechanism of actionContraindications/cautionsAdverse effects/interactions
Aminophylline/reverse dipyridamole/125–250 mg by slow intravenous infusionRapid onset and peak; half-life of 8 h; 50%–70% plasma protein bound; antagonizes all adenosine receptorsNo absolute contraindication; however, caution in patients with porphyria, hyperthyroidism, hypertension, arrhythmia, heart failure, and liver dysfunctionAdverse effects include CNS stimulation, gut disturbances, headache, and palpitations; interactions include xanthine products and medications, medications altering liver metabolism, acyclovir, allopurinol, some antiarrhythmics, antidepressants, cimetidine, disulfiram, fluvoxamine, interferon-α, macrolide antibacterials and quinolones, oral contraceptives, tiabendazole, viloxazine, phenytoin and antiepileptics, phenobarbitone, ritonavir, rifampicin, sulfinpyrazone, lithium, macrolides, pancuronium, and phenytoin
Nitroglycerin/relieve acute angina/300- to 600-μg sublingual tablet or 1–2 sprays of 400 μg each onto or under tongue or 2- to 3-mg buccal tablet1–3 min until onset; half-life of 2–3 min; duration of 30–60 min; facilitates nitric oxide metabolism, which causes vasodilation and reduced preload and afterloadContraindicated in hypotension, hypovolemia, and increased intracranial pressure; contraindicated with phenytoin, alteplase, levofloxacin, and sildenafil; caution in renal and liver dysfunction and hypothyroidismAdverse effects include flushing, dizziness, tachycardia and headache; interactions include alcohol, antihypertensives, and vasodilators
Salbutamol/relieve dyspnea and bronchospasm/1–2 inhalations of 100 μg each, with third inhalation if necessary 1 min after second5 min until onset; peak at 60 min; half-life of 4–6 h; duration of 3–6 h; direct-acting β2-agonist to dilate bronchiContraindicated in hypotension; caution in hyperthyroidism, myocardial insufficiency, hypertension, arrhythmia, and diabetes mellitusAdverse reactions include tremor, palpitations, tachycardia, anxiety, headaches, peripheral vasodilation, muscle cramps, hyperglycemia, and hypersensitivity; interactions with other β2-agonists, corticosteroids, diuretics, xanthines, β-blockers, and antidepressants
  • Some adverse effects are more likely when used therapeutically than in single adjunctive doses.