A resent paper by David Browning published in the American Journal of Ophthalmology* discussed the impact of the AAO revised guidelines regarding plaquenil screening. Regardless of the validity of “objective” testing, the paper reminds us that we should all be using plaquenil pertinent questions in our history taking of these patients.

This article discusses what a relevant set of pertinent questions may look like. If you are already familiar with plaquenil and the AAO guidelines, skip the background section and go to the pertinent questions section that follows.


Background

Plaquenil (hydroxychloroquine) is an anti-inflammatory drug used in the treatment of malaria and in the treatment of rheumatoid arthritis and systemic lupus erythematosus. Side effects include toxic maculopathy, which can result in permanent loss of central vision. Withdrawal of medication is the only treatment for toxic maculopathy caused by plaquenil.

Typically, a prescribing physician will refer a patient beginning plaquenil treatment to an ophthalmologist for a baseline exam. Subsequent exams are scheduled based upon the level of risk for developing maculopathy. Most ophthalmologists prefer to see any plaquenil patient (high risk or not) at least once a year.

Dosing is usually limited to 200mg twice a day, for a total of 400mg/day.

A patient with any of the following risk factors is considered to be in the high risk category (high risk for maculopathy):

1. Has taken plaquenil for more than 5 years.
2. Has taken 1000g or more of the drug. A person taking 400mg/day would arrive at this total after 5 years on the drug.
3. Is taking a dose greater than 6.5mg/kg/day. A patient taking the usual dose of 400mg/day would be in the high risk category if he/she weighed under 136 lbs.
4. Older patients (>70 years old?).
5. Concomitant renal or liver disease.
6. Pre-existing maculopathy.

Plaquenil pertinent questions

Given the above risk factors, an effective set of pertinent questions would include the following, as suggested in the paper sited:

1. Current dose (in mg/day)
2. Duration of treatment (in years)
3. Height (in inches, pt. reported)
4. Weight (in pounds, pt. reported)
5. Ideal body weight (per calculation)
6. Renal or liver disease?
7. Maculopathy (AMD, pigment changes, etc.)?

Ideal body weight an be computed using this formula:

Women: 100 lbs + 5 lbs for every inch over 5 feet.
Men: 110 lbs + 5 lbs for every inch over 5 feet.

*David J. Browning, Impact of the Revised American Academy of Ophthalmology Guidelines Regarding Hydroxychloroquine Screening on Actual Practice, American Journal of Ophthalmology, Volume 155, Issue 3, March 2013, Pages 418-428.e1, ISSN 0002-9394, 10.1016/j.ajo.2012.09.025.