Hydroxychloroquine (HCQ) is an antimalarial drug that has been used for decades to treat malaria, lupus, and rheumatoid arthritis. In recent years, HCQ has received a lot of attention as a potential treatment for COVID-19. However, there are concerns about the safety of HCQ, especially with long-term use. In this article, we’ll explore whether HCQ is hard on the body.
How does HCQ work?
HCQ is a disease-modifying antirheumatic drug (DMARD). It helps to reduce pain, swelling, and inflammation in conditions like rheumatoid arthritis and lupus. HCQ is thought to work by changing the levels of certain immune system chemicals, called cytokines, that cause inflammation.
HCQ enters cells easily and concentrates in cellular compartments, including lysosomes. In lysosomes, HCQ raises the pH, which interferes with the function of enzymes involved in cell processes. This may inhibit the production of cytokines and other inflammatory molecules.
Is HCQ safe?
When used short-term, HCQ is generally safe and well-tolerated. The most common side effects are nausea, vomiting, diarrhea, and stomach pain. These mild side effects usually go away within a few weeks once the body adjusts to the medication.
However, HCQ treatment lasting longer than 5 years may cause irreversible eye damage and vision loss. HCQ can build up in retinal cells over time, causing damage. Regular eye exams are recommended while taking HCQ long-term.
There are also concerns about the risk of heart rhythm problems, like QT prolongation, with long-term HCQ treatment. QT prolongation means it takes longer for the heart to recharge between beats. This increases the risk of dangerous irregular heart rhythms.
Other potential side effects
With long-term use, HCQ may also cause:
- Nerve damage
- Muscle weakness
- Hair loss
- Skin rash and itching
- Mood changes
- Blood disorders
Does HCQ damage the heart?
There is conflicting evidence about HCQ’s effects on the heart. Some studies have found no increased risk even with years of treatment, while others show potentially harmful changes.
One study looked at 350 patients treated with HCQ for nearly 9 years on average. There were no differences in rates of cardiovascular side effects compared to patients not taking HCQ.
However, a review of 28 studies found QT prolongation and cardiomyopathy (enlarged, thickened heart muscle) in some lupus patients after long-term HCQ treatment. The risk increased beyond 5 years of use.
Overall, there may be a small increase in risk of heart side effects in susceptible individuals taking high doses long-term. Patients with existing heart conditions may be more vulnerable.
Does HCQ affect the liver or kidneys?
HCQ is processed by the liver and excreted by the kidneys, so there are concerns about potential damage to these organs. However, research suggests the risk is low when HCQ is used at recommended doses.
One study followed 700 lupus patients taking HCQ for up to 15 years. There were no differences in liver or kidney function compared to lupus patients not treated with HCQ.
HCQ has even been safely used in patients with pre-existing liver and kidney disease. However, regular monitoring of liver and kidney function is still advised while taking HCQ long-term.
Is HCQ risky for certain groups?
Some groups may be more susceptible to HCQ’s side effects:
As we age, liver and kidney function decline, making it harder to process and eliminate medications. Older patients may be more likely to experience side effects from HCQ accumulation.
Patients with heart conditions
Those with existing heart problems like arrhythmias and cardiomyopathy may have worse symptoms due to HCQ’s effects on the heart.
Patients with vision problems
Retinal damage is one of HCQ’s most concerning side effects. Those with macular degeneration or other retinal diseases may be at higher risk.
HCQ can cross the placenta and may rarely cause complications like visual disorders in infants exposed during pregnancy. However, many lupus and rheumatoid arthritis patients safely take HCQ while pregnant.
Can HCQ use be safely monitored?
To lower risks when taking HCQ long-term, doctors recommend:
- Annual eye exams to check for retinal changes
- Periodic EKGs to monitor heart rhythm
- Regular blood work to assess liver and kidney function
- Taking the lowest effective HCQ dose
- Avoiding high-risk combinations like with QT-prolonging drugs
With close monitoring, HCQ side effects are often reversible if caught early. If vision, heart, liver, or kidney problems occur, reducing the HCQ dose or stopping the medication may prevent permanent damage.
Are there alternatives to HCQ with fewer side effects?
For lupus and rheumatoid arthritis, some alternatives may be safer long-term options. However, these other DMARDs also require close monitoring as they carry risks too.
Non-biologic DMARD alternatives
Biologic DMARD alternatives
- Tumor necrosis factor (TNF) inhibitors like etanercept (Enbrel) and infliximab (Remicade)
- Non-TNF biologics like rituximab (Rituxan) and abatacept (Orencia)
For malaria prevention, alternatives to HCQ include atovaquone-proguanil (Malarone) and doxycycline. Mefloquine may also be used, but carries a higher risk of neuropsychiatric side effects.
The bottom line
When used short-term or at lower doses, HCQ has a relatively mild side effect profile. But with long-term use beyond 5 years, the risks of irreversible eye and heart damage increase.
To reduce these risks, doctors carefully screen patients before prescribing long-term HCQ and monitor them regularly for vision changes, heart issues, and problems with blood counts, liver function and kidneys.
Alternative DMARDs are available that may be safer options long-term for conditions like lupus and rheumatoid arthritis. However, all DMARDs have risks and benefits that must be weighed individually for each patient.