Hydroxychloroquine (HCQ)

HCQ is a DMARD used to treat inflammatory types of arthritis, such as rheumatoid and psoriatic arthritis.

HCQ is taken orally.

HCQ comes in 200 mg tablets. The usual dose is between one and two tablets per day (200 to 400 mg per day). If you are taking two tablets a day you can take them all at once or divide them up: one in the morning and one in the evening. The maximum amount of HCQ you can take is based on your body weight. HCQ is often used with other drugs, such as methotrexate (MTX) and/or sulfasalazine (SSZ), in combination therapy.

The mechanism of action for this medication is not well understood. It is thought that hydroxychloroquine interferes with the ability of immune system cells to communicate with each other and thereby decreasing inflammation.

Like with many other DMARDs, you will not feel the effects of HCQ right away. Most people start noticing the effects about six to eight weeks after they start to take the medication, but full benefit may not be apparent for up to three months. It is important to be patient and continue taking your medication.

If you have existing problems associated with the retina of the eye (see below), HCQ may not be an appropriate treatment option for you. Please discuss this with your health-care provider.

If you experience any changes to your vision while on HCQ discontinue therapy and contact your health-care provider immediately.

Anyone who has had a previous allergic reaction to HCQ should avoid the medication.

HCQ is likely compatible with pregnancy and has been used safely in clinical practice. Data suggests that the drug does not pose significant fetal risk and the medication is often continued during pregnancy. Please discuss treatment options with your health-care provider if you are planning a pregnancy or become pregnant.

HCQ is generally well tolerated. Rare side effects associated with HCQ include upset stomach, diarrhea, headaches and dizziness. HCQ can also cause a rash, darkening of the skin and ringing in the ears. If you develop a rash or ringing in the ears while on HCQ, please contact your health-care provider.

HCQ can sometimes make your skin more sensitive to the sun, meaning you may sunburn more easily.

In rare cases, HCQ can cause problems with your vision and with the back of the eye (retina). The most common vision-related issue are corneal deposits. This is usually due to high daily doses or HCQ and rarely occurs at doses of 400 mg per day or less. The deposits do not affect vision but can cause sensitivity to light and the appearance of halos or rings around lights. Very rarely HCQ can cause deposits at the back of the eye (retinal deposits). If this occurs, you might notice blurred vision, decreased night and peripheral vision, difficulties focusing your eyes, reading or seeing words and letters, and parts of objects may also appear to be missing. Damage to the retina is extremely rare in cases where a person has been taking HCQ for less than two years. However, once damage occurs, it may be permanent, therefore, appropriate monitoring of your eyes is essential.

Take HCQ exactly as prescribed. Taking it with food or milk can help reduce stomach upset. You may notice that you are more sensitive to sun exposure while taking HCQ, so be sure to use sunscreen regularly.

An ophthalmologic exam is recommended prior to starting HCQ, then periodically once you have started HCQ. This is to ensure the medication isn’t affecting your vision and the back of your eye. Please discuss this with your health-care provider prior to starting HCQ.

On occasion, your health-care provider may request blood tests while taking HCQ. Your health-care provider may meet with you regularly to ensure that HCQ is adequately controlling your inflammatory arthritis and not causing adverse effects.

A repeat ophthalmologic exam is not usually required during the first five years of HCQ therapy. After five years an ophthalmologic exam is required yearly. If you are at a higher risk for HCQ-induced eye problems an ophthalmologic exam may be required every year after starting HCQ. Risk factors that may increase the likelihood of eye problems include liver or kidney disease, obesity, age (60 and older) and pre-existing diseases of the eye

Store this medication at room temperature (15 to 30 degrees Celsius) and keep it out of reach of children.