Which of the following is a stimulant that can contribute to tachycardia?

• A. Aspirin
• B. Caffeine
• C. Acetaminophen
• D. Lisinopril

Answer: (B)

Tachycardia results from substances that stimulate the nervous system and push the heart to beat faster. Caffeine is a well-known stimulant; it blocks adenosine receptors in the brain and increases the release of norepinephrine, which together raise heart rate and blood pressure. This is why caffeine can contribute to tachycardia, especially in larger amounts or in sensitive individuals.

Aspirin doesn’t stimulate the heart; it mainly affects clotting and pain/inflammation. Acetaminophen is a pain reliever and fever reducer with little cardiovascular stimulatory effect. Lisinopril is an ACE inhibitor that lowers blood pressure rather than stimulating the heart, so it doesn’t typically cause tachycardia as a direct effect.

So, the stimulant that can contribute to tachycardia is caffeine.