Anti-malarials were first derived from the bark of cinchona tree in 1820 & have been in use for arthritis since 1960.
1) Chloroquine (Aralen)
2) Hydroxychloroquine (Plaquenil)
Amongst these, hydroxychloroquine is the most commonly used medication for Rheumatoid Arthritis, SLE. It acts by reducing the activation of dendritic cells (one of the immune cells) & thereby reduces the joint inflammation. It has proven efficacy in controlling the joint inflammation of RA. Thus, Hydroxychloroquine is not a painkiller but a DMARD (Disease modifying ant-rheumatic drug- an actual anti-arthritis drug).
As seen previously, we have more than 50 years experience of the drug & it is one of the safest DMARD. It is not the most potent of the lot & is always combined with other DMARDs to boost their effectiveness.
Hydroxychloroquine is a well-tolerated medication & serious side effects are rare. The most common side effect is its bitter taste. The bitter aftertaste can cause nausea in some. Taking the tablet along with food, rather than after food, can take care of this problem. It can also cause acidity & the same generally settles with proper diet & routine antacid medications.
It tends to affect the skin pigmentation in a few individuals. Over pigmentation (darkening of the skin) can occur & should be brought to notice of your Rheumatologist. You can reduce the chances of over-pigmentation by wearing a full-sleeve dress/ a sunscreen & using an umbrella when in the sun.
More serious side effect includes retinopathy (manifests as visual changes or loss of vision). Medical literature emphasizes that over 1,000,000 patients have used either Chloroquine or Hydroxychloroquine, while only 20 cases of retinal toxicity have occurred in individuals using appropriate doses. In addition, all of these reported patients with retinal toxicity were using the drugs for more than 5 years. The incidence of retinal toxicity with Hydroxychloroquine treatment is estimated to be about 1 in 50,000 patients & is thus extremely rare. The same can be prevented by regular eye examination & self use of amsler grid. You can download the Amsler grid here.
Apart from the anti-arthritis properties it also has additional benefits-
1) Reduces the blood glucose & helps diabetics
2) Improves serum lipids
All in all, hydroxychloroquine is a safe DMARD. Though it is not the most potent but definitely helps other DMARDs put RA in remission.