Hydroxychloroquine Side Effects, Usefull Information, Before Taking & More

Hydroxychloroquine is an externally administered medication sold under a number of brand names with Plaquenil being the most common one.  This medication is an anti-rheumatic agent and also acts as an anti-malarial drug. It belongs to the class of medications known as 4–aminoquinoline.


It is used for a number of medical conditions. It is widely used to treat and prevent certain types of malaria (especially chloroquine-sensitive malaria). Its mode of actions also makes it useful to treat rheumatoid arthritis, discoid and systematic lupus erythematosus, and porphyria cutanea tarda.

The medication may also be used for purposes not mentioned in this guide.


Side effects of Hydroxychloroquine

Just like the rest of the medications, Hydroxychloroquine too has some side effects. These side effects range from mild to severe.

Some of the common side effects that are considered to be mild in nature are as follows:

  • Headaches
  • Ringing in your ears
  • Dizziness
  • Feeling drowsy
  • Nausea and vomiting
  • Stomach pain
  • Loss of appetite
  • Weight loss
  • Mood swings
  • Signs of irritability such as agitation
  • Hair loss
  • Signs of an allergic reaction like skin rashes, itching, etc.


Most of the side effects tend to occur at the start of the treatment and perish within a day or two as it does not take long for the body to adjust and get accustomed to the presence of the medicine. However, they may persist and start to worsen, triggering serious medical conditions. Therefore, seek medical help promptly if any side effect is experienced.

Apart from these, it also has some serious side effects such as:

  • Headaches accompanied by pain in the chest, severe dizziness, and fluctuating heartbeats.
  • Fainting
  • Slow heart rate
  • Weakness in muscles
  • A sensation of numbness or tingling
  • Signs and symptoms of low blood sugar such as a headache, hunger, sweating, irritability, dizziness, etc.
  • Signs and symptoms of low blood cell count, i.e., fever, chills, sore throat, weakness, swollen gums, etc.


Note that other side effects that have not been listed in this guide may also be experienced. Usually, doctors and pharmacists inform the patients about the side effects they may are likely to experience at the start of their treatment.

For further queries and concerns regarding this, you may consult your healthcare provider.


How to use?

Before starting, you are strongly advised to read the directions on the prescription label and follow them carefully.

For prevention, start taking your dose 2 weeks before going to areas where malaria is prevalent and continue using it for at least 8 weeks after you come back. For the treatment of malaria, you are usually required to take the medicine for 3 days starting from a high dose leading to the smaller one. However, if your doctor directs you otherwise, then you are to follow his/her instructions. Do not overdose nor skip your doses.



  • Do not use or recommend it without a doctor’s consent.
  • It may interact negatively with some medicines. Thus, let your doctor know about the medicines, if any, that you use.
  • It is suitable for some people under certain circumstances. Therefore, give yours and your family’s medical history to your doctor.
  • If you become pregnant while taking it or are nursing a baby, inform your doctor immediately.
  • Keep it away from children’s reach, heat, sunlight, and moisture.