Plaquenil (hydroxychloroquine) is an antimalarial drug that is commonly prescribed to treat RA, systemic lupus erythematosus, and some other rheumatic diseases. This class of medications has a long history. Antimalarial medications that are also useful in treating arthritis were first developed from the bark of the Peruvian cinchona tree.
Plaquenil is one of a group of slow-acting medications used to treat RA. People who take this medication must realize that it will take a few weeks to a few months before they see improvement in their symptoms. In my own practice, when I ask people to start this medication, I typically have them schedule their next appointment for two months because this is a good time interval to check for improvement. Because the benefits of Plaquenil take so long to become apparent, some patients may find it necessary to take it in conjunction with other medications that work in the interim period.
Plaquenil is generally well tolerated. The most common side effect is upset stomach, although Plaquenil doesn't contribute to stomach ulcer formation (unlike NSAIDs and corticosteroids). A skin rash can occur in patients who are allergic to the medication. Sometimes dizziness, blurred vision, or headache may occur. When the drug is taken over a long period of time, bleaching of the hair or gray discoloration of the skin can occur. Blood problems are very uncommon with this medication, so Plaquenil requires very little monitoring of blood tests.
There is a very remote possibility that Plaquenil may cause pigment deposition in the retina (the back of the eye) and lead to vision loss in some patients. Although the chance of this side effect occurring while you are taking Plaquenil at the prescribed dosage is very remote, it is still a good idea to see an eye doctor. The first visit to the eye doctor should be scheduled after about six months of treatment with the medication, and then annually thereafter. The eye doctor will check carefully for any evidence of pigment deposition in the macula (the central part of the retina) and perform other tests to look for any subtle change in vision. The eye doctor may also give you an Amsler Grid, a useful tool for monitoring your central visual field at home. This test is important for detecting early and sometimes subtle visual changes.
Plaquenil has the potential to cause damage to an unborn child, which is an important concern for women of childbearing age who take this drug. The conventional advice is that this medication, like many other arthritis medications, should be stopped prior to becoming pregnant. Small series of case reports in the medical literature reporting on women who took these medications during pregnancy and had healthy babies suggest that Plaquenil is safe for use during pregnancy. Nevertheless, the risks and benefits must be carefully weighed, and you should definitely discuss this issue with your doctor.
In general, Plaquenil is well tolerated and is ideally suited for people with mild RA. It is also frequently used in combination with other medications such as methotrexate.
I've been taking Plaquenil along with my methotrexate since 1993. It's important to have your eyes examined once a year while you're taking Plaquenil. I have had no side effects from this medication.
—Jim