Which plant causes cardiotoxicity in the digitalis-like glycoside toxicosis category?

• A. monkshood (aconitum)
• B. azalea (rhododendron)
• C. dogbane (apocynum)
• D. sweet potato (ipomea)

Answer: (A)

Digitalis-like glycoside toxicosis comes from plants that contain cardiac glycosides which inhibit the Na+/K+-ATPase in heart cells. This inhibition increases intracellular calcium, boosting the force of contraction but also disrupting electrical conduction, leading to arrhythmias and other cardiac signs.

Among common toxic plants, dogbane is the one that carries these cardiac glycosides and can cause cardiotoxic effects similar to digitalis. The other plants use different toxic mechanisms: monkshood contains aconitine alkaloids that affect voltage-gated sodium channels; azalea and rhododendron have grayanotoxins that also alter sodium channels in a different pattern; sweet potato species are not known for digitalis-like glycosides.