HYDROXYCHLOROQUINE (Plaquenil®) & CHLOROQUINE (Aralen®) INFORMATION SHEET

Developed by Andy Thompson MD FRCPC

What is Chloroquine / Hydroxychloroquine?

Chloroquine (Aralen®) and Hydroxychloroquine (Plaquenil®) are Disease Modifying Anti-Rheumatic Drugs (DMARDs). Chloroquine was initially uses to treat parasitic infections such as malaria. Since the 1950’s they have also been recognized to be beneficial for the treatment of Rheumatoid arthritis, Systemic Lupus Erythematosus, and other types of arthritis and rheumatic disease. Occasionally doctors use Chloroquine or Hydroxychloroquine for diseases other than arthritis.

How does Chloroquine / Hydroxychloroquine work?

The mechanism by which these medications have their benefit in arthritis is unknown.

Why am I taking Chloroquine or Hydroxychloroquine?

Your doctor has prescribed this medicine to help with the following:

1. Reduce the pain and swelling (inflammation) in your joints.
2. Improve your day to day function.
3. Improve the symptoms of Lupus such as rashes, mouth sores, and joint swelling.

What is the usual dose of Chloroquine / Hydroxychloroquine?

• Hydroxychloroquine is available in 200 mg tablets. The dose is based on your lean body weight with the standard dose ranging from one tablet (200 mg) to two tablets (400 mg) per day. The dose should be no more than 6.5 mg/kg/day of lean body weight.
• Chloroquine is available in 250 mg tablets. The dose is based on your lean body weight with the standard dose ranging from one-half (125 mg) to one tablet (250 mg) per day. The dose should be no more than 3 mg/kg/day of lean body weight.

How often do I take Chloroquine / Hydroxychloroquine?

• Hydroxychloroquine is taken ONCE to TWICE a DAY.
• Chloroquine is taken ONCE a DAY.

Who should NOT take Chloroquine / Hydroxychloroquine?

• Patients who have had a previous reaction to Chloroquine / Hydroxychloroquine.
• Patients who have had eye problems as a result of Chloroquine or Hydroxychloroquine.

When will I start to feel the effects of Chloroquine / Hydroxychloroquine?

These medications do not work right away. They will take about 6 to 12 weeks before you start feeling better. The maximum effect can take up to 6 months.

What Medications are safe with Chloroquine / Hydroxychloroquine?

Virtually all medications can be safely used with Chloroquine and Hydroxychloroquine. As an example, some of the medications your doctor may prescribe safely include: Acetaminophen (Tylenol), Prednisone, Non-Steroidal Anti-Inflammatory Drugs (NSAIDs), Other DMARDs (i.e. Sulfasalazine, Methotrexate, and Gold), and Biologics (i.e. Etanercept, Infliximab, Anakinra).

What are the side-effects of Chloroquine / Hydroxychloroquine?

Chloroquine and Hydroxychloroquine are very well tolerated medication and most patients have no side-effects at all.

MORE COMMON side-effects include:

• Mild nausea, loss of appetite, and occasional stomach cramps.
• Diarrhea.
• Mild blurry vision at first.

RARE side-effects include:

• Skin rashes including a blue/black discolouration of the skin and worsening of psoriasis.
• Heightened sensitivity to the sun.
• Headaches or dizziness.
• Nervousness, restlessness, and difficulty sleeping.
• Ringing in the ears (tinnitus) - rare.
• Muscle Weakness: Rarely, Hydroxychloroquine can cause weakness of the muscles. If you notice weakness, it should be reported to your doctor.
• Eyes: Rarely, Chloroquine and Hydroxychloroquine can cause damage to the back of the eye (retina). The most common symptoms are difficulty reading or seeing (words, letters, or parts of objects may be missing) or blurred vision. The retinal toxicity seems to be related to the daily dose of medication. Fortunately, this is very rare.

Why do I need to see an Ophthalmologist (Eye Doctor) when I am taking Chloroquine / Hydroxychloroquine?

As mentioned above, Chloroquine and Hydroxychloroquine can cause damage to the back of the eye (retina). Early eye toxicity is not usually a serious problem. However, once serious damage occurs, it is permanent. Therefore, appropriate monitoring of the eye by a medical specialist familiar with the side-effects of Chloroquine and Hydroxychloroquine is essential. The eye examination includes regular tests such as vision and eye pressure. It also includes tests which are not part of a regular eye check-up such as testing for colour vision and testing your visual fields. Your doctor will usually ask you to see an ophthalmologist every 6 - 24 months.

How can I help to minimize the side-effects of Chloroquine / Hydroxychloroquine?

• Take your medication as prescribed by your doctor.
• Take your medication with food to help reduce stomach upset.

Do I need to have regular blood tests while taking Chloroquine / Hydroxychloroquine?

NO, you do not need to have regular blood tests while taking Chloroquine or Hydroxychloroquine. However, your doctor may order periodic blood tests to follow the activity of your arthritis.

How do I stop the Chloroquine / Hydroxychloroquine?

You do not need to wean yourself off Chloroquine or Hydroxychloroquine. They can simply be stopped. However, your disease may “flare” after you stop the medicine.

What should I do if I miss a dose of Chloroquine / Hydroxychloroquine?

• If you forget to take your Chloroquine or Hydroxychloroquine at the usual time but remember later on the same day, take the missed dose immediately.
• If you forgot to take yesterday’s dose, skip yesterday’s dose and take your usual dose for today.

Is Chloroquine / Hydroxychloroquine safe in pregnancy?

• It is generally advisable to avoid all medications during pregnancy and while you are trying to become pregnant. However, Chloroquine & Hydroxychloroquine are believed to be some of the safer medications and have been used safely and successfully to treat arthritis during pregnancy.
• Please notify your doctor if you become pregnant while taking Chloroquine or Hydroxychloroquine.