Is a side effect of Cocaine miosis or mydriasis?

Is a side effect of Cocaine miosis or mydriasis?

• A. Miosis
• B. Mydriasis
• C. Ptosis
• D. Nystagmus

Answer: (B)

Pupil size is controlled by two opposing systems: the dilator pupillae, which enlarges the pupil under sympathetic stimulation, and the sphincter pupillae, which constricts it under parasympathetic control. Cocaine increases norepinephrine in the synapse by blocking its reuptake, boosting sympathetic nerve activity. This heightened sympathetic signal targets the dilator pupillae via alpha-1 receptors, causing the pupil to dilate. That dilation, called mydriasis, is the expected side effect. Miosis, the opposite constriction, would occur with increased parasympathetic activity or opioid effects, not with cocaine. Ptosis is eyelid droop and not a typical direct result of cocaine’s action. Nystagmus is an involuntary eye movement and isn’t the characteristic pupil response of cocaine use.

Pupil size is controlled by two opposing systems: the dilator pupillae, which enlarges the pupil under sympathetic stimulation, and the sphincter pupillae, which constricts it under parasympathetic control. Cocaine increases norepinephrine in the synapse by blocking its reuptake, boosting sympathetic nerve activity. This heightened sympathetic signal targets the dilator pupillae via alpha-1 receptors, causing the pupil to dilate. That dilation, called mydriasis, is the expected side effect.

Miosis, the opposite constriction, would occur with increased parasympathetic activity or opioid effects, not with cocaine. Ptosis is eyelid droop and not a typical direct result of cocaine’s action. Nystagmus is an involuntary eye movement and isn’t the characteristic pupil response of cocaine use.