Digoxin (Lanoxin) is a cardiac glycoside that is among the oldest medications used for heart failure.
What are its two primary actions?

The correct answer is Choice D: Headache.

Choice A rationale: Nausea is not a common adverse effect of sublingual nitroglycerin. Nausea may occur in some patients, but it is usually mild and transient.Nausea may be related to the vasodilatory effects of nitroglycerin, which can cause hypotension and reflex tachycardia1. Nausea may also be caused by other factors, such as anxiety, stress, or food intolerance.Nausea is not a specific indicator of nitroglycerin toxicity or overdose2.

Choice B rationale: Bradycardia is not a common adverse effect of sublingual nitroglycerin. Bradycardia is a slow heart rate, usually defined as less than 60 beats per minute.Bradycardia may occur in some patients who take nitroglycerin, especially in combination with other drugs that affect the heart rate, such as beta-blockers, calcium channel blockers, or digoxin3. Bradycardia may also be caused by other factors, such as vagal stimulation, hypothyroidism, or electrolyte imbalance.Bradycardia is not a specific indicator of nitroglycerin toxicity or overdose2.

Choice C rationale: Hypertension is not a common adverse effect of sublingual nitroglycerin. Hypertension is a high blood pressure, usually defined as more than 140/90 mmHg.Hypertension may occur in some patients who take nitroglycerin, especially in those who have a history of hypertension, renal impairment, or volume overload4. Hypertension may also be caused by other factors, such as stress, pain, or caffeine intake.Hypertension is not a specific indicator of nitroglycerin toxicity or overdose2.

Choice D rationale: Headache is a common adverse effect of sublingual nitroglycerin.Headache may occur in up to 80% of patients who take nitroglycerin, especially during the first few days of therapy or after an increase in dose5. Headache may be related to the vasodilatory effects of nitroglycerin, which can cause cerebral vasodilation and increased intracranial pressure. Headache may also be caused by other factors, such as dehydration, sinusitis, or migraine. Headache is usually mild to moderate in intensity and can be relieved by analgesics, such as acetaminophen or aspirin.Headache is not a specific indicator of nitroglycerin toxicity or overdose

Alpha 1 adrenergic blocking agents have a vasodilating effect and can be used for the management of hypertension. They work by blocking the alpha 1 receptors on the vascular smooth muscle, which normally cause vasoconstriction when stimulated by catecholamines like epinephrine and norepinephrine.By preventing this constriction, alpha 1 blockers lower the peripheral resistance and blood pressure

Choice A is wrong because alpha 3 adrenergic blockers do not exist.There are only two types of alpha receptors: alpha 1 and alpha 2

Choice B is wrong because alpha 2 adrenergic antagonists do not have a vasodilating effect.

They block the alpha 2 receptors, which are located presynaptically on the sympathetic nerve terminals and postsynaptically on some vascular smooth muscle cells.Alpha 2 receptors inhibit the release of norepinephrine when activated, so blocking them would increase the sympathetic activity and vasoconstriction

Choice C is wrong because alpha 1 adrenergic agonists do not have a vasodilating effect.

They stimulate the alpha 1 receptors, which cause vasoconstriction and increase the blood pressure.Alpha 1 agonists are used to treat hypotension and nasal congestion