Can Tropicamide cause Bradycardia (brady)?

From the Guidelines

Tropicamide is highly unlikely to cause bradycardia due to its anticholinergic properties and minimal systemic absorption when applied topically to the eye. Tropicamide is used primarily as a mydriatic agent to dilate the pupils during eye examinations, and it works by blocking the parasympathetic nervous system in the eye, causing pupil dilation and paralysis of accommodation. While anticholinergic medications can sometimes affect heart rate, tropicamide typically causes tachycardia (increased heart rate) rather than bradycardia when systemic anticholinergic effects occur 1.

Key Points to Consider

• The management of bradycardia typically involves the use of atropine, dopamine, or other medications, as outlined in the 2018 ACC/AHA/HRS guideline on the evaluation and management of patients with bradycardia and cardiac conduction delay 1.
• Tropicamide's standard dosing is 1-2 drops of 0.5% or 1% solution in the eye, with effects lasting 4-6 hours.
• Patients with pre-existing cardiac conditions should inform their eye care provider before receiving tropicamide.
• If a patient experiences bradycardia after tropicamide administration, it would be unusual and might be related to other factors or medications.

Clinical Implications

• Tropicamide is not expected to cause bradycardia, and its use is generally safe in patients without pre-existing cardiac conditions.
• However, patients with pre-existing cardiac conditions should be monitored closely after receiving tropicamide, and any unusual heart rhythm changes should be reported promptly to a healthcare provider.
• The treatment of bradycardia, if it were to occur, would follow established guidelines, such as those outlined in the 2018 ACC/AHA/HRS guideline 1.

From the FDA Drug Label

ADVERSE REACTIONS ... Non-Ocular: ... tachycardia, ... have been reported with the use of tropicamide. The FDA drug label does not answer the question.

From the Research

Tropicamide and Bradycardia

• There is limited evidence directly linking tropicamide to bradycardia. However, a case report 2 describes a late-preterm newborn who developed severe bradycardia after administration of a collyrium containing 1% phenylephrine and 0.95% tropicamide.
• Another study 3 found that the average heart rate decreased by a mean of 4.96 beats/minute from the baseline following instillation of phenylephrine 2.5% and tropicamide 0.5% drops in preterm infants. However, this decrease was not statistically significant, and bradycardia was only observed in infants with underlying respiratory distress syndrome.
• A study on the mechanisms of anti-cholinergic drug-induced bradycardia 4 suggests that atropine-induced bradycardia may be due to central vagal stimulation or a peripheral mechanism involving M1-antagonism. However, it is unclear whether tropicamide has a similar mechanism.
• The majority of the studies 5, 3, 4 do not provide strong evidence for a direct link between tropicamide and bradycardia. One study 6 reports on the recreational misuse of tropicamide, but does not provide information on its cardiovascular effects in a clinical setting.
• Overall, while there is some evidence suggesting that tropicamide may be associated with bradycardia in certain cases 2, 3, more research is needed to fully understand the relationship between tropicamide and bradycardia.