Cocaine is described as a potent cardiac toxin that can cross the placenta and breast milk.

• A. Cocaine
• B. Methamphetamine
• C. Heroin
• D. Cannabis

Answer: (A)

Cocaine has a potent combination of effects on the heart and on fetal/newborn exposure. It acts as a strong sympathetic stimulant and vasoconstrictor, mainly by blocking the reuptake of norepinephrine and dopamine. This leads to tachycardia, hypertension, and coronary vasospasm, increasing the risk of myocardial ischemia and arrhythmias. At the same time, cocaine readily crosses the placenta and enters breast milk because of its high lipid solubility and small size, so both the fetus and the breastfeeding infant are exposed. In the fetus, reduced placental blood flow and direct cardiac stimulation can cause fetal distress, while in a breastfed infant exposure can produce tachycardia, irritability, poor feeding, or other effects. While other stimulants like methamphetamine also cross the placenta and can affect the heart, the description of a potent cardiac toxin with clear placental and lactational transfer is most classically associated with cocaine.