Hydroxychloroquine

What is Hydroxychloroquine?

Hydroxychloroquine is a quinolone medicine used for treating and preventing malaria. It is also used as a disease-modifying anti-rheumatic drug (DMARD) to treat autoimmune diseases. It comes in the form of oral tablets that you can only buy through a prescription. It is also available under the brand name Plaquenil among others. It is also available in a generic version, but in some cases, you may not find it in every dosage strength or form as its brand-name alternatives. It is also used as combination therapy along with other drugs.

What is Hydroxychloroquine used for?

It is an immunomodulatory drug used for 60 years to treat malaria and autoimmune diseases like inflammatory arthritis and systemic lupus. Nowadays, it is also used for treating antiphospholipid syndrome, juvenile idiopathic arthritis, and primary Sjogren’s syndrome. Hydroxychloroquine can lower the mortality rates of patients with lupus erythematosus. It is also known to reduce the risk of lupus nephritis.

In some cases, Hydroxychloroquine is consumed along with Doxycycline to prevent malaria. 

Can I use Hydroxychloroquine for coronavirus infection or Covid-19?

The WHO does not recommend using Hydroxychloroquine for Covid-19. However, it was in clinical trials initially; WHO later pulled it out as the results were not promising. Hydroxychloroquine does not lower the mortality rates in COVID-19 or the need for mechanical ventilation by patients. Using Hydroxychloroquine for covid-19 leads to more unwanted effects than a placebo.

Hydroxychloroquine mechanism of action

The exact mechanism of HCQ is not known completely, but there are several hypotheses about how it works.

For malaria: The primary theory behind its effectiveness against malaria lies in its ability to block the detoxification process in the plasmodium parasites.

The malaria parasites (plasmodium) first invade the RBC and then ingest hemoglobin from the cytosol into the food vacuole. Then it uses the decomposed hemoglobin for synthesizing amino acids proteins for its growth. The decomposed hemoglobin (consists of ferriprotoporphyrin IX (FPIX) haematin) eventually transformed into nontoxic crystallized polymers named hemozoin.

The food vacuole is a lysosomal isolated acidic compartment, and the HCQ is a weak alkaline. As a result, HCQ diffuses the vacuole membrane and turns itself into a protonated form, which the parasite cannot diffuse out.

The accumulated HCQ in the food vacuole destabilizes the FPIX, thereby inhibiting its polymerization, and inducing parasite cell lysis.

Another theory suggests that HCQ targets the nucleus, not the lysosome. It can directly interact or bind to the parasite’s DNA and RNA and inhibits its replication and transcription process.

For autoimmune diseases: Researchers state that CQ/HCQ can affect the activity of lysosomes and autophagosomes. These organelles are responsible for antigen processing, presentation, and autoimmune activation.

Hydroxychloroquine accumulates in lysosomes and increases the intra-lysosomal PH. As a result, it impairs lysosomes and autophagosomes’ ability to mature, thereby inhibiting autoimmune activation.

Some studies say HCQ can modify the lysosomal function by clocking the fusion between lysosome and autophagosome.

Hydroxychloroquine side effect

Some common side effects of Hydroxychloroquine include nausea, vomiting, diarrhea, loss of appetite, headache, and dizziness. Although these side effects are less severe, you must contact your doctor if the symptoms persist or worsen.

Some severe side effects of Hydroxychloroquine that needs immediate medical attention:

• Slow heartbeat
• Symptoms of heart failure (difficulty in breathing, swelling of ankles or feet, unusual tiredness, or rapid weight gain)
• Mood changes (anxiety, racing thoughts, depression, hallucinations, and suicidal thoughts)
• Hearing changes (ringing in the ears, hearing loss)
• Infection (sore throat)
• Easily bruised skin
• Sign of liver disease (severe abdominal pain, dark urine, yellowing eyes/skin, or stomach cramps)
• Muscle weakness or uncontrollable muscle movements
• Hair loss
• Hair/skin color changes

Precautions Before taking Hydroxychloroquine

• Some people may have an allergy to Hydroxychloroquine or any inactive ingredients. Talk to your doctor if you notice any allergic reactions or other issues.
• You need to inform about your medical history and ongoing medication with the doctor.
• Tell your doctor if you have a medical history of enzyme problems, vision or eye problems, kidney diseases, hearing issues, skin problems, blood disorders, or seizures.
• Hydroxychloroquine may affect the blood sugar of diabetic patients. Your doctor may advise you to check your blood sugar while taking the medication. If you feel low blood sugar symptoms, you need to call your doctor right away.
• HCQ may also react with alcohol and marijuana by intensifying the dizziness and increasing of risk of developing liver problems.
• The medication can also make you sensitive to the sun. Try to avoid going outside as much as possible, or wear protective clothing and sunscreen before going outdoors.
• The drug can also affect your heart rhythm, a condition known as QT prolongation. Tell your doctor if you have heart problems or have a family history of heart issues. Your chances of QT Prolongation may increase if you have low potassium or magnesium in the blood. This happens if you use diuretics or water pills. It may also occur due to severe sweating, vomiting, or diarrhea. Ask your doctor how to take Hydroxychloroquine safely.
• If you are pregnant, trying to get pregnant, or breastfeeding, you must take this medication only if your doctor thinks it is the best treatment.

How should I take Hydroxychloroquine?

• Take HCQ precisely as prescribed by your healthcare professional.
• You can take the medication with a meal or a glass of milk unless instructed differently by your doctor.
• Generally, Hydroxychloroquine is prescribed to patients with lupus or arthritis. Meanwhile, it is prescribed one dose per week to treat malaria. Thus if you need Hydroxychloroquine, buy it online UK after a consultation with your doctor.

Dosing information (Usual dose- may vary among individuals)

For Malaria (Areas where Chloroquine resistance is not reported)

Adults: 400mg salt orally once a week (310 mg base)

Weight-based Dose: 6.5 mg/kg salt (5 mg/kg base)

Maximum Dose: 400 mg   

For malaria (for uncomplicated malaria)

Adults: 800 mg salt (620 mg base) as an initial dose, followed by 400 mg salt (310 mg base) at 6, 24, and 49 hours.

Total dose: 2000 mg salt (1550 mg base)

Weight-base dose:

1st dose: 13 mg/kg salt

2nd dose: 6.5 mg/kg salt after 6 hours of the first dose

3rd dose: 6.5mg/kg salt after 24 hours of the first dose

4th dose: 6.6 mg/kg salt after 48 hours of the first dose

Maximum dose:

Initial dose: 800 mg salt

2nd, 3rd, and 4th dose: 400mg salt

For Systemic Lupus Erythematosus:

200 mg to 400 mg salt divided into 1 or 2 doses

For Rheumatoid Arthritis:

1st Dose: 400-600 mg salt divided into 1 or 2 doses

Maintenance dose: 200-400 mg salt divided into 1 or 2 doses

Maximum Dose: 600 mg salt or 6.5 mg/kg salt (whichever is lowest)

The dosage mentioned above is a generalized version and should not be taken by adult patients without consulting a doctor. The Hydroxychloroquine dosage for pediatric purposes must be strictly prescribed by a physician.