Ivermectin Dosages & Reactive Mydriasis

A temporary side effect responsive to dose reduction

Summary

• Ivermectin can cause reactive mydriasis often presenting as blurred vision

• This condition generally resolves unremarkably within 12 hours of discontinuance

• There is likely an absolute daily dose threshold, irrespective of bodyweight, that leads to neurologic side effects

If you've ever had a comprehensive eye exam at the eye doctor, which typically requires pupil dilation, you've probably experienced some degree of persistent mydriasis. It's a temporary condition that resolves within a couple of hours. Nonetheless, I still hate the inability to focus clearly after the procedure even with perfect correction afforded by my gas perm contact lenses.

But this condition, often termed reactive mydriasis or pharmacologic mydriasis, is not unique to the examination room. Per the American Academy of Ophthalmology:

“Most commonly, the medications, drugs, and toxins that cause pupillary dilation act via iris parasympathetic receptor blockade (anticholinergic mydriasis) but sympathetic stimulation (e.g., topical epinephrine) can also produce lesser degrees of pharmacologic mydriasis (without impairing the light/near reaction).”¹

Here's a table of pharmaceuticals that can cause mydriasis presented from the above referenced article.

Where's Ivermectin?

I have personally witnessed multiple instances of reactive mydriasis experienced by “overweight” (BMI > 25.0-29.9 kg/m^2) individuals who were following the more aggressive 0.4-0.6 mg/kg dosing schedule for variants of concern suggested by Front Line COVID-19 Critical Care Alliance (FLCCC protocol). Every instance resolved within 12-14 hours of ivermectin discontinuance.

A quick search of VigiAccess for ivermectin adverse events yields the following:

To my knowledge, ivermectin has traditionally been dosed up to 0.2 mg/kg pre COVID. Even combining visual impairment, vision blurred, and mydriasis, we still see a nearly non-existent reporting rate after billions of doses administered over 30 years.

My Ivermectin Experience

I used 42 mg (0.5 mg/kg) of ivermectin daily without any side effects during my COVID infection. But I have read instances where others have experienced vision problems with 0.2 mg/kg weekly prophylactic doses - presumably much less than 42 mg daily dosing.

Early Treatment With Colchicine, Not Ivermectin, Saved My Life From Severe COVID

Apart from this condition being a somewhat individualistic response, my hypothesis is there is a threshold dose (in mg), irrespective of bodyweight, that generally predisposes neurologic side effects such as reactive mydriasis.

1. Pharmacologic Dilation of Pupil, American Academy of Ophthalmology EyeWiki