Final answer:
Calcium channel blockers and Beta-adrenergic agonists should not be given to cardiac patients for preterm labor. Oxytocin is commonly used instead.
Step-by-step explanation:
The drugs that cardiac patients should NOT receive for preterm labor are a) Calcium channel blockers and b) Beta-adrenergic agonists. These drugs can have negative inotropic effects, which means they decrease the strength of contraction and SV (stroke volume). Administering them to cardiac patients may worsen their condition and pose serious risks. Instead, other drugs like d) Oxytocin are commonly used to induce or enhance labor contractions in preterm labor.