Hydroxychloroquine Print Page

What are hydroxychloroquine (Plaquenil) and chloroquine (Aralen)?

  • These medications are in a class of medications called Disease Modifying Anti-Rheumatic Drugs, or DMARDS. DMARDs are a slow acting but effective treatment for rheumatoid arthritis and other forms of inflammatory arthritis.
  • They are also known as “anti-malarials” since that is their original use; it does not mean you have malaria.Anti-malarial drugs are likely the safest of all DMARDs, but also mild in terms of its effect. They are useful for early and mild cases of inflammatory arthritis. More often, they are used in combination with other DMARDs.
  • Another common use is in the treatment of some forms of lupus and other connective tissue diseases.

What is the typical dose?

  • Hydroxychloroquine – Doses usually range between 200mg and 400mg per day, or 1-2 tablets/day.
  • Chloroquine – Usually 250mg per day.

How do anti-malarials work?

  • While there has been extensive research into this area, it remains unclear as to the exact mechanism of action. It is thought they change the pH in certain cells, which modulates their immune function.

How soon will I feel the effects of anti-malarials?

  • Like all DMARDs, they take time to work. Most patients start to feel their positive effects at 6-8 weeks, with maximum benefit at 3-6 months. Side effects can occur earlier.

Is there anything I can do to reduce these side effects?

  • Stomach Upset – for those taking two tablets, try splitting the dose. Also try taking it with or without food.
  • Nightmares – Take your medication earlier in the day.
  • Rash, muscle irritation – stop your medication and call your physician
  • Let your physician know if you have any liver or kidney problems

Anti-malarials sound scary. What is the chance I can lose my vision?

  • Retinal damage and subsequent vision loss is very rare, more rare with hydroxychloroquine than chloroquine. However, there are a number of steps you and your physician can take to reduce this risk:
    • Let your physician know if you have any other eye or retinal problems which could influence the use of this medication
    • Ensure you are on an appropriate dose – for hydroxychloroquine, it is based on your weight.
    • Visit your ophthomologist (eye surgeon) annually. They can look at your retina and see if there is any early damage BEFORE you have any vision loss. If they see anything concerning, the anti-malarial can be stopped with no further damage.

What should I do if I miss a dose?

  • You can take your anti-malarial any time in the day. In other words, if you usually take it in the morning and miss your dose, it is ok to take in the evening. If you forgot your pills for the day altogether, do not take an extra dose the next day; just resume your regular dose. As long as this does not happen regularly, you will likely not feel any ill effects.

How do I safely stop anti-malarials?

  • It is safe to just stop them; you do not need to slowly reduce the dose. However, keep in mind, if you were gaining any benefit, it will usually take at least 6 weeks to lose it.


For more information about hydroxychloroquine, or for questions that are specific to your situation, always consult your physician.

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