Antimalarial Medications


Antimalarial medications are amongst the most commonly used oral medications for rheumatologic skin diseases.  They include hydroxychloroquine (commonly still referred to by its original brand name, Plaquenil), chloroquine, and quinacrine.

Fast facts

  • Hydroxychloroquine (Plaquenil) is the drug of choice for many physicians who treat rheumatologic skin diseases. It is the most readily available and frequently prescribed antimalarial in the US.
  • Antimalarial medications are extremely safe and do not overtly suppress the immune system.
  • Patients taking hydroxychloroquine and chloroquine should be monitored by an ophthalmologist to screen for a very rare eye side effect called antimalarial retinopathy.
  • Quinacrine, which does not cause retinopathy, is used commonly in combination with, or in patients who cannot take, hydroxychloroquine or chloroquine. It is not widely available and must be obtained from a compounding pharmacy.


Initially used to treat and prevent malaria, these medications are now used to control inflammation in rheumatologic diseases, especially lupus.  Antimalarials control both skin and systemic inflammation in lupus.  They have also been used to treat the skin changes of dermatomyositis and morphea.

How they work

The precise manner in which antimalarial agents exert their therapeutic effect in controlling lupus and other rheumatologic skin diseases is unclear. It is believed that hydroxychloroquine interferes with communication of cells in the immune system.


Hydroxychloroquine and chloroquine are dosed based on a patient’s ideal body weight to minimize side effects, especially retinopathy.  If the weight-based dose is not exceeded, eye side effects are rare.  The typical dose of hydroxychloroquine for adults is 200 mg to 400 mg per day, while the average dose of quinacrine is 100 mg daily.   Patients take between125 mg and 250 mg of chloroquine daily, based on their ideal body weight.

Time to effect

It is important to note that there is a delayed response with antimalarial medications.  Symptoms can start to improve in 1-2 months, but it may take as long as 6 months before the full benefit of these medications are seen.  Since they are such extremely safe and effective medications, a patient should not stop them before they have a chance to start working.

Side effects

The antimalarial medications typically are very well tolerated, and serious side effects are extremely rare. The most common side effects are nausea and diarrhea.  These side effects often improve with time or by taking the medication with food. Less common side effects include allergic skin rashes, bruise-like changes in the skin, hair changes (bleaching or thinning of hair), and muscle weakness. Lowering of the white blood cell count or liver function test elevation have rarely been reported with hydroxychloroquine and chloroquine usage.  Additionally, the drugs can cause anemia (low red blood cell counts) in some individuals.  A blood test screening may be recommended by your doctor.

In very rare cases, hydroxychloroquine or chloroquine can cause visual changes (retinopathy), but such vision problems are more likely to occur in patients taking high doses for many years, in persons 60 years or older, or in those with significant kidney disease. The daily dose used today is considerably lower than the doses originally used to treat lupus and rheumatoid arthritis.  At the current recommended dose, development of visual problems while taking this medication is extremely rare.

Quinacrine is a yellow-colored medication and may cause the skin or conjunctivae, and even tears and saliva to appear slightly yellow.  This can be confused with jaundice which results from poor liver function.  The yellow discoloration caused by quinacrine is harmless and will go away relatively quickly by decreasing the dose or stopping the drug altogether.  Quinacrine extremely rarely causes decreases in all of the cells made by the bone marrow (white blood cells, red blood cells and platelets).  Patients who are going to develop this side effect often have a rash prior to the drop in blood cells.

Points to remember

Although vision problems while taking hydroxychloroquine or chloroquine are very rare, you should notify your doctor if you notice any changes in your vision. Patients should have baseline screening and regular eye exams, every 6 to 12 months while taking this medication. Visual changes experienced early on or seen early during regular eye exams typically improve after stopping the medication.

Periodic blood tests may be recommended to evaluate for rare side effects of anemia, lowering of the white blood count, and liver function elevation.

Patients who are pregnant or are considering having a child, should talk to their doctor before taking these medications.  There is now general agreement among doctors that hydroxychloroquine is safe during pregnancy, and is used to prevent flares in pregnant patients with systemic lupus.  However, any medication taken during pregnancy should be discussed with a physician.

Drug interactions

Although there are few drug interactions with hydroxychloroquine, to be safe, patients should notify their physicians about all of the medications they are taking, including over-the-counter drugs and natural remedies.  Hydroxychloroquine can interact with digoxin, and old medication that is used to treat heart problems.  Chloroquine decreases the effectiveness of ampicillin.  The antimalarial medications do not work well in patients who smoke for uncertain reasons.

Information to discuss with your primary care physician and other specialists

It is important to notify your other physicians that you are taking than antimalarial medication.  Antimalarials do not have a strong effect on the immune system, so vaccines recommended by other physicians are generally acceptable, and it is not necessary to stop these medications before surgery. Be sure to notify your ophthalmologist if you are taking either hydroxychloroquine or chloroquine so you can have the correct screening tests.

For more information

The Rheumatologic Dermatology Society (RDS) has compiled this list to give you a starting point for your own additional research. The RDS does not endorse or maintain these Web sites, and is not responsible for any information or claims provided on them. It is always best to talk with your dermatologist for more information and before making any decisions about your care.

National Institutes of Health: Medline Plus

ACR Position Statement on screening for hydroxychloroquine retinopathy

Lupus Foundation of America on Antimalarials in Lupus