The maximum oral dose of digoxin is expressed in which unit?

• A. Micrograms
• B. Liters
• C. Moles
• D. Milligrams

Answer: (D)

The key idea is that drug doses are given as a amount of substance, with milligrams being the standard unit for most oral medications. For digoxin, the common tablet strengths are 0.125 mg and 0.25 mg, and dosing charts typically describe the maximum daily amount in milligrams (for example, up to about 0.5 mg/day). Using milligrams keeps dosing practical and aligns with the available tablet strengths, reducing the need to deal with fractional micrograms in everyday prescribing.

Liters measure volume, not amount of drug, so they don’t apply to dose. Moles are a chemical amount and aren’t used for everyday dosing descriptions in this clinical context. Micrograms could describe very small doses, but the conventional, labeled dosing for digoxin’s maximum oral dose is expressed in milligrams, matching standard tablet strengths.