Chloroquine should be taken exactly as prescribed by a healthcare provider. The following general guidelines can help ensure proper use:

• Oral Tablets: Chloroquine is usually taken with food to reduce stomach upset. It is important to swallow the tablets whole, not crush or chew them.
• For Malaria Treatment: If chloroquine is being used for malaria treatment, it should be taken in a specific dosing schedule, typically starting with a higher dose and then following up with additional doses over the next 2-3 days.
• For Malaria Prevention: When used for malaria prevention, chloroquine is typically taken once a week, starting 1-2 weeks before travel to a malaria-endemic area, and continuing for 4 weeks after returning.
• For Autoimmune Conditions: For conditions like lupus and rheumatoid arthritis, chloroquine is typically taken once daily. The dosage may need to be adjusted over time based on the patient’s response to treatment.

Patients should not skip doses or stop taking chloroquine without consulting their doctor, as this can increase the risk of the condition returning or worsening.

Chloroquine works by disrupting the ability of the malaria parasite to digest hemoglobin, a protein found in red blood cells. The parasite feeds on hemoglobin by breaking it down into smaller parts. Chloroquine interferes with this process, preventing the parasite from properly digesting the hemoglobin, which eventually leads to its death.

In addition to its antimalarial effects, chloroquine is used in autoimmune diseases because it can modulate the immune system. It is believed to interfere with the activity of certain immune system components, reducing inflammation and altering the course of diseases like lupus and rheumatoid arthritis. By decreasing the activity of certain immune cells and suppressing the production of inflammatory molecules, chloroquine helps to manage symptoms of these conditions.

While chloroquine is generally safe when used as directed, it can cause side effects, especially with long-term use or in higher doses. Some common side effects include:

• Gastrointestinal Issues: Nausea, vomiting, stomach cramps, and diarrhea are some of the most common side effects of chloroquine.
• Headache: Some people experience headaches, dizziness, or lightheadedness while taking chloroquine.
• Skin Reactions: Chloroquine can cause rashes or other skin reactions, especially in people with allergies or sensitivities.
• Vision Problems: Long-term use of chloroquine can cause retinal damage, leading to vision problems. Regular eye exams are recommended for patients on long-term chloroquine therapy.
• Muscle Weakness: In rare cases, chloroquine can cause muscle weakness or affect the nervous system, especially with prolonged use.
• Hearing Problems: Some people may experience hearing loss or ringing in the ears (tinnitus), although this is uncommon.

In the case of serious side effects like difficulty breathing, chest pain, or sudden vision changes, immediate medical attention should be sought.

There are several important warnings and precautions to keep in mind when using chloroquine:

• Eye Exams: Patients on long-term chloroquine therapy should have regular eye exams, as the drug can cause retinal damage and vision loss if used for extended periods.
• Heart Disease: Chloroquine can affect the heart, potentially causing irregular heart rhythms (arrhythmias), especially in people with pre-existing heart conditions.
• Liver and Kidney Disease: People with liver or kidney disease may be at increased risk of chloroquine toxicity. Dosage adjustments may be necessary.
• Pregnancy and Breastfeeding: Chloroquine is considered safe for use during pregnancy when prescribed by a doctor, particularly for malaria treatment. However, it should only be used during pregnancy when the benefits outweigh the risks. It is excreted in breast milk, so it should be used cautiously in breastfeeding women.

Chloroquine can interact with other medications, which can either increase or decrease its effectiveness or cause adverse effects. Key interactions include:

• Antacids: Antacids containing aluminum or magnesium may reduce the absorption of chloroquine, making it less effective.
• Antiepileptic Drugs: Drugs like phenytoin and phenobarbital may increase the metabolism of chloroquine, reducing its effectiveness.
• Cimetidine: This medication, used to reduce stomach acid, may increase the levels of chloroquine in the blood, potentially leading to toxicity.
• Other Antimalarials: Combining chloroquine with other antimalarial drugs, such as quinine or mefloquine, can increase the risk of side effects, including toxicity.
• Corticosteroids: If combined with steroids, chloroquine can increase the risk of side effects like muscle weakness.

As always, it’s important to inform your healthcare provider about all medications you’re currently taking, including prescription, over-the-counter, and herbal supplements.

Chloroquine dosages can vary depending on the condition being treated:

• Malaria Treatment:
  • Adults: Typically, 600 mg is given initially, followed by 300 mg at 6, 24, and 48 hours.
  • Children: The dosage is based on body weight. The exact dose will be determined by the child’s healthcare provider.
• Malaria Prevention:
  • Adults: Usually, 300 mg once a week, starting 1-2 weeks before traveling to a malaria-endemic area and continuing for 4 weeks after returning.
• Rheumatoid Arthritis and Lupus:

Adults: The usual dose is between 200 mg to 400 mg daily, depending on the severity of the condition and the patient’s response.

Chloroquine is a prescription medication and should be used under the guidance of a healthcare provider. It is available in most countries as a prescription-only drug due to the potential for side effects, especially with long-term use. It is important to follow the prescribed dosage and attend follow-up appointments for monitoring.

1. What is chloroquine?
   An antimalarial medication used to prevent and treat malaria.

2. How does chloroquine work?
   It interferes with the growth of parasites in red blood cells.

3. What diseases does chloroquine treat?
   Malaria, certain autoimmune diseases like lupus and rheumatoid arthritis.

4. Is chloroquine effective against malaria?
   Yes, particularly effective against strains sensitive to it.

5. What is the typical dosage of chloroquine?
   Dosage varies by condition; follow medical prescription closely.

6. Are there any side effects of chloroquine?
   Possible side effects include nausea, headache, vision changes, and muscle weakness.

7. Can chloroquine cause serious toxicity?
   Yes, in overdose or misuse, it can cause heart, liver, or retinal toxicity.

8. Is chloroquine safe during pregnancy?
   It is sometimes used during pregnancy, but consult a healthcare provider.

9. Can chloroquine be used for COVID-19?
   It was investigated, but results showed limited efficacy and potential risks.

10. Does chloroquine interact with other medications?
    Yes, it can interact with other drugs; always inform your doctor.

11. How should chloroquine be stored?
    Store in a cool, dry place away from sunlight.

12. Is chloroquine available over the counter?
    No, it requires a prescription.

13. What happens if I miss a dose?
    Take as soon as remembered unless it’s near the next dose; do not double dose.

14. Can chloroquine cause vision problems?
    Long-term use can cause retinal damage; regular eye exams are advised.

15. How quickly does chloroquine act?
    Symptoms usually improve within days of starting treatment.

16. Is chloroquine effective against drug-resistant malaria?
    No, resistance is common; other treatments are preferred.

17. Can chloroquine be given to children?
    Yes, with appropriate dosage and medical supervision.

18. Are there any allergies associated with chloroquine?
    Some people may be allergic; report symptoms like rash or swelling.

19. What should I do in case of chloroquine overdose?
    Seek emergency medical attention immediately.

20. Can chloroquine be used prophylactically?
    Yes, it can be used to prevent malaria in certain regions.