Hydroxychloroquine (Plaquenil) is a medication that can help reduce inflammation in the body. Doctors do not commonly use it to treat psoriatic arthritis (PsA).
However, Plaquenil may help some people with PsA who have not had success with other treatments.
PsA is a long-term autoimmune condition that affects the joints. Around 30% of people with psoriasis develop PsA.
PsA currently has no cure, but some treatments may slow disease progression and reduce the painful, debilitating symptoms it causes.
This article describes how Plaquenil may help a person with PsA. It also looks at the potential side effects, risks, and benefits of the drug.
Doctors used to use Plaquenil to treat some types of malaria. They now use it to treat inflammatory autoimmune conditions, including rheumatoid arthritis, juvenile arthritis, and lupus.
If a person has an autoimmune condition, their immune system attacks the body, causing pain and potential damage. Plaquenil dampens down this mistaken immune reaction, thereby helping reduce the damage.
Because Plaquenil can change the disease course of some forms of arthritis, doctors consider it a disease-modifying antirheumatic drug. It helps prevent joint damage and may reduce the risk of long-term disability.
People may need to use Plaquenil for up to 12 weeks before noticing any improvement in their symptoms.
There have been few studies that support the use of Plaquenil for PsA.
The American College of Rheumatology states that Plaquenil may help with PsA but that doctors usually avoid it for this purpose because it can cause psoriasis flares.
The Food and Drug Administration (FDA) has approved Plaquenil to treat:
- malaria
- discoid lupus erythematosus, which is a chronic inflammatory skin condition
- systemic lupus erythematosus, which is a chronic inflammatory condition
- rheumatoid arthritis
Doctors may decide to use Plaquenil off-label if they think that someone with PsA would benefit from the medication. Off-label use means using a drug to treat a condition that it does not have approval for.
For someone with rheumatoid arthritis or lupus, a doctor may prescribe Plaquenil as a disease modifier. The drug may:
reduce pain and inflammation- prevent joint damage
- help someone retain their physical ability
Although doctors do not fully understand how Plaquenil works, they believe that it prevents the immune system from overreacting and causing inflammation.
Most studies looking at Plaquenil for rheumatoid arthritis are older. One
Because Plaquenil may reduce inflammation and help those with rheumatoid arthritis, some people with PsA may also benefit from this medication.
Most people tolerate Plaquenil well. Severe side effects are rare. If a person experiences any side effects, they may improve over time.
Some potential side effects of Plaquenil include:
- nausea
- diarrhea
- rash
- skin darkening or spots
- changes to hair
- muscle weakness
Occasionally, Plaquenil can cause anemia in people with a condition called G6PD deficiency, or porphyria.
Some people may experience vision loss or changes with Plaquenil. This is particularly likely if they:
- are over 60 years of age
- have kidney or liver disease
- have underlying retinal disease
- take Plaquenil at high doses over several years
However, when a person takes Plaquenil at the recommended dose, vision-related side effects are rare. Still, doctors recommend that a person has an eye exam in the first year of taking Plaquenil, then further exams every 1–5 years.
There are also rare reports of heart rhythm changes with this drug, mainly when using it alongside other medications.
It seems that doctors may avoid using Plaquenil because of a possible risk of psoriasis flares or worsening symptoms.
However, one 2015 study suggests this is not always the case. Using information from the Psoriatic Arthritis Registry of Turkey, the researchers looked at 746 people with PsA who were using or who had used Plaquenil. Only two people stopped using the treatment because of an increase in psoriasis symptoms.
These results indicate that Plaquenil may not cause psoriasis flares despite current thinking.
The dosage of Plaquenil a person may take for PsA depends on:
- their age
- their body weight
- the severity of their PsA
- other medical conditions they have
- how they first react to the medication
Plaquenil comes in the form of oral tablets. Because the FDA has not approved the medication for treating PsA, the manufacturers do not publish recommended dosages for this condition. Instead, a person’s doctor must decide if Plaquenil is a good option for them and determine the most suitable dose.
For reference, adults with rheumatoid arthritis typically take 200 milligrams (mg) to 400 mg per day. They may take this in one dose or two. Some people may take higher doses.
Plaquenil has few drug interactions. Nevertheless, people should tell a doctor about all the medications and supplements they are taking.
People should also notify an eye doctor if they are taking Plaquenil so that they can perform regular visual screening tests. In one study, five participants experienced retinopathy, which is a condition that damages the blood vessels at the back of the eye. By undergoing regular tests, people can lower their risk of eye problems.
Plaquenil is likely safe to take during pregnancy and while breastfeeding. That said, anyone who is pregnant, considering becoming pregnant, or lactating should check with a doctor before taking this medication.
People taking Plaquenil should also talk with a doctor if they experience any side effects, if their condition worsens, or if they do not notice any improvement in their condition after taking Plaquenil for several weeks.
Doctors may recommend Plaquenil treatment for some individuals with PsA.
The FDA has approved Plaquenil for some inflammatory conditions, including rheumatoid arthritis and lupus. Because the drug can help with these conditions by reducing the inflammatory immune response, it may also help with PsA.
However, people should remember that there is little clinical evidence supporting the use of Plaquenil for PsA. Additionally, doctors may avoid using it for this purpose because it may increase psoriasis flares. However, limited evidence suggests that this is unlikely.