What instruction should patients taking phenytoin sodium follow to prevent a common adverse effect?

Patients taking phenytoin sodium should follow the instruction of practicing good dental hygiene and reporting gum swelling or bleeding to prevent a common adverse effect known as gingival hyperplasia. Phenytoin is known to alter the metabolism of connective tissue in the gums, leading to overgrowth of the gum tissue. By practicing good oral hygiene and promptly reporting any signs of gum swelling or bleeding to their healthcare provider, patients can help prevent the worsening of this side effect.

Option A is not directly related to preventing adverse effects of phenytoin sodium but rather focuses on general infection control measures. Option B, although important for overall health, is not specifically indicated for preventing adverse effects of phenytoin sodium. Option C, while a good dietary recommendation for general health, is not directly related to preventing the adverse effects of phenytoin sodium.