Hydroxychloroquine is in a class of medications called Disease Modifying Anti Rheumatic Drugs (DMARDs). Hydroxychloroquine is used in the treatment of SLE and rheumatoid arthritis. It was originally designed to treat malaria and occassionally still used for this. Hydroxychloroquine has antiinflammatory, antithrombotic, and immunomodulatory properties.
It normally takes 2-3 months to notice the benefit from hydroxychloroquine.
Hydroxychloroquine is recommended in nearly everyone with SLE. It helps treat the arthritis, rash, and many of the other milder symptoms of SLE. It also reduces the risk lupus flares and damage to other organs (by >25%).
In rheumatoid arthritis, it is often added to methotrexate as combination therapy to help improve the signs and symptoms of arthritis.
The recommended dose is no more than 5mg/kg. It comes as a 200mg tablet in New Zealand - so most people take 1-2 tablets daily based on their body weight.
Hydroxychlroquine has a bitter taste so is best taken with food.
Most patients get no side effects. About 10% may get some mild stomach side effects such as gas or diarrhoea, which often is at the start of treatment and improves with ongoing use of the medication.
Hydroxchloroquine can increase sensitivity to sunlight, so always cover up and wear good sunscreen (even more important to patients using it for SLE).
Other serious side effects are rare but can include retinal (back of eye) toxicity after taking the medication at high dose for >5 years. Some international guidelines suggest an eye test as baseline then after 5 years - but baseline testing is not routine in Auckland as the risk of eye toxicity is very low (<1/1000 after 5 years). The standard practice in Auckland is eye screening after 6 years of hydroxychloroquine or a total cummulative dose of 1000g which ever comes first. However, if you have any underlying eye problems or want to have baseline screening then it an be done via an ophthalmologist.
There is no interaction with hydroxychloroquine and alcohol.
The standard advice for moderate consumption of alcohol applies. If you have no underlying liver problems, you can drink a maximum of 14 units of alcohol per week. You should drink no more than 3 units in any one day (which is equivalent to about 2 small glasses of wine). Ideally have 2-3 alcohol free days per week.
Blood tests are not normally needed for hydroxychloroquine. In both RA and SLE you will probably have blood tests for other reasons including disease activity assessment or other medication monitoring
Response to treatment is usually assessed every 2-3 months. If there is inadequate benefit then other medications may be added to sulfasalazine.
Eye screening can be done at baseline (not essential), but then after 6 years or >1000mg cummulative dose 1-2 yearly eye testing including detailed assessment of the retina including macula is needed.
Hydroxychloroquine is usually safe in pregnancy. Some of the medication is passed in breast mild so the safety of breastfeeding is unclear but also thought to be relatively safe.
It is important that the underlying disease (i.e. RA or SLE) is well controlled prior to getting pregnant, so this needs to be discussed with your rheumatologist and family doctor prior to trying to concieve.
Our recommendations for vaccines if you are on hydroxychloroquine are:
1. Influenza vaccine (yearly)
2. Vaccination against pneumoccocal disease (Prevenar 13 and Pneumovax 23 - every 5 years)
3. Vaccination against haemophilus influenza b (Hiberix)
4. Vaccination against meningoccoal disease (Menectra)
If using hydroxychloroquine alone with no other DMARDs or biological medications then all other vaccines including live vaccines (e.g. Shingles, MMR, yellow fever, typhoid) are fine to have.