Which medication is NOT available as a transdermal dosing form?

Atenolol is primarily available in oral dosage forms, specifically as tablets. While other medications like nitroglycerin, fentanyl, and scopolamine do have transdermal systems available, atenolol does not offer a transdermal patch or similar form.

Nitroglycerin is available as a patch for the prevention of angina, fentanyl is offered as a patch for pain management, and scopolamine is provided as a patch for motion sickness. These transdermal systems allow for a continuous delivery of the medication over an extended period, which is beneficial for maintaining stable drug levels in the body. In contrast, atenolol's formulation and administration routes do not include transdermal options, making it the correct answer for this question.