Which of the following effects is unlikely to occur after giving a 50-kg adult an intramuscular dose of 0.6 mg atropine sulfate?

Explanation

Atropine sulfate, when administered intramuscularly at this dose, typically causes an increase in heart rate (tachycardia), not a decrease (bradycardia). It also reduces salivation and sweating and causes pupil dilation (mydriasis). Therefore, slowed heart rate is not an expected effect.