I have a question about the drug, Plaquenil, AKA hydroxychloroquine. My interest stems from the book I am writing, Nurse Mary’s Guide to Rheumatoid Arthritis. After reading several additional medical reports about Plaquenil, I realized I needed to look further and to expand its section in the medication chapter of my book.

Another reason for my interest was that I had been taking Plaquenil for six years for my RA.  I was taking it in addition to methotrexate injections and Medrol. I had  also been taking it while I was taking tamoxifen for breast cancer. I no longer take tamoxifen as I developed a rare serous uterine cancer associated with using the drug.

None of my doctors questioned the risk involved in taking both drugs. I also made the mistake in thinking Plaquenil was a mild drug. In fact, it does treat mild RA and more aggressive RA when given in combination with other drugs. The drug itself is not mild.

Hydroxychloroquine was developed as an antimalarial in 1955. It was a refined version with fewer side effects than the widely used drug, Atabrine.  Malaria was a huge problem for soldiers serving in the South Pacific during World War II. Soldiers were pretreated and treated with Atabrine.  The treated soldiers that had rheumatoid arthritis or lupus were shown to also have improvement with their diseases. This association was noted by the medical community. Hydroxychloroquine, Plaquenil, was eventually approved for use in lupus and rheumatoid arthritis patients. Today it is an accepted drug in both of these diseases.

The usual side effects of nausea and diarrhea abate after a month or two on the drug. One of the important complications involves the eye.

The concern is the potential for eye damage.  Irreversible retinal damage has been observed in some patients. Risk factors increase with those who received long term treatment with this drug, those on concurrent treatment with tamoxifen which has been known to induce retinal toxicity, or those with subnormal glomerular filtration rate. For those who have used the drug less than ten years, there is a 2% risk of eye damage. That means that two people in every hundred treated will have eye damage.

Asians more often experience an atypical pattern of retinopathy. It is called pericentral neuropathy. Eye exams need to be extended beyond the macula so that eye damage is not missed.

It is strongly recommended that a base line eye exam is given when a patient starts a treatment plan of Plaquenil. Exam includes examining the eyes for visual acuity, central vision field, color vision, and fundoscopy. The exam, according to the drug manufacturer, should be repeated at least annually on everyone taking the drug. The medical community recommends a baseline exam and then a yearly exam after five years. Those at high risk should receive a yearly exam.

Plaquenil has a long half-life. It remains in a person’s body for eight months.

I no longer take the medication. Plaquenil is an important drug for those suffering with lupus. It is also an important drug for certain types of malaria. I have RA. It is not an important drug for me.

Bibliography

Sanofi-Aventis. Product monograph; Plaquenil. http://products.sanofi.ca/en/plaquenil.pdf.

Shippey III, MD, Eugen Alexander; Wagler, DO FACP FACR, Vanya D.; Collamer, MD, FACP, FACR, Angelique N.;   Hydroxychloroquine: An old drug with new relevance; Cleveland Clinic Journal of Medicine, Volume 85, Number 6, June 2018.

Plaquenil (AvKARE.inc) FDA package insert. MedLibrary.org