Chloroquine 250mg Tablets
It is used to treat or prevent malaria. It is used to treat a type of bowel infection.It may be given to you for other reasons. Talk with the doctor.
Drug Class
Antimalarial; Disease-Modifying Antirheumatic Drug (DMARD)
Pharmacologic Class
4-aminoquinoline
Pregnancy Category
C
FDA Approved
Apr 1949
DEA Schedule
Not Controlled
Overview
What is this medicine?
Chloroquine is a medication primarily used to prevent and treat malaria, a serious disease caused by parasites. It's also used to treat certain autoimmune conditions like rheumatoid arthritis and lupus. It works by interfering with the parasites' ability to survive or by calming down an overactive immune system.
How to Use This Medicine
Taking Your Medication Correctly
To get the most benefit from your medication, follow your doctor's instructions carefully. Read all the information provided with your prescription and follow the instructions closely. You can take this medication with or without food, but if it causes stomach upset, take it with food to help minimize discomfort.
It's essential to continue taking this medication as directed by your doctor or healthcare provider, even if you start feeling well. Do not stop taking the medication without consulting your doctor first.
Important Interactions to Avoid
Do not take antacids or kaolin within 4 hours of taking this medication, as they may interfere with its effectiveness.
Storing and Disposing of Your Medication
Store your medication at room temperature in a dry place, away from the bathroom. Keep all medications in a safe location, out of the reach of children and pets. When disposing of unused or expired medication, do not flush it down the toilet or pour it down the drain unless instructed to do so by your pharmacist. Instead, check with your pharmacist for guidance on the best way to dispose of your medication. You may also want to explore local drug take-back programs in your area.
What to Do If You Miss a Dose
If you miss a dose, take it as soon as you remember. However, if it's close to the time for your next scheduled dose, skip the missed dose and resume your regular dosing schedule. Do not take two doses at the same time or take extra doses to make up for the missed one.
To get the most benefit from your medication, follow your doctor's instructions carefully. Read all the information provided with your prescription and follow the instructions closely. You can take this medication with or without food, but if it causes stomach upset, take it with food to help minimize discomfort.
It's essential to continue taking this medication as directed by your doctor or healthcare provider, even if you start feeling well. Do not stop taking the medication without consulting your doctor first.
Important Interactions to Avoid
Do not take antacids or kaolin within 4 hours of taking this medication, as they may interfere with its effectiveness.
Storing and Disposing of Your Medication
Store your medication at room temperature in a dry place, away from the bathroom. Keep all medications in a safe location, out of the reach of children and pets. When disposing of unused or expired medication, do not flush it down the toilet or pour it down the drain unless instructed to do so by your pharmacist. Instead, check with your pharmacist for guidance on the best way to dispose of your medication. You may also want to explore local drug take-back programs in your area.
What to Do If You Miss a Dose
If you miss a dose, take it as soon as you remember. However, if it's close to the time for your next scheduled dose, skip the missed dose and resume your regular dosing schedule. Do not take two doses at the same time or take extra doses to make up for the missed one.
Lifestyle & Tips
- Take chloroquine with food or milk to reduce stomach upset.
- Do not take antacids (like Tums, Maalox, Mylanta) within 4 hours of taking chloroquine, as they can reduce its absorption.
- If taking for malaria prophylaxis, start taking it 1-2 weeks before traveling to a malaria-prone area, continue weekly during your stay, and for 4 weeks after returning.
- Avoid excessive sun exposure and use sunscreen, as chloroquine can increase sun sensitivity.
- Report any new or worsening vision changes immediately to your doctor.
- Attend all scheduled eye exams and other monitoring appointments.
Available Forms & Alternatives
Available Strengths:
Dosing & Administration
Adult Dosing
Standard Dose:
Varies by indication. For malaria treatment: 1000 mg (600 mg base) initially, then 500 mg (300 mg base) at 6, 24, and 48 hours. For malaria prophylaxis: 500 mg (300 mg base) once weekly. For rheumatoid arthritis/lupus: 250 mg (150 mg base) daily or 500 mg (300 mg base) daily.
Dose Range:
250 - 1000 mg
Condition-Specific Dosing:
Malaria Treatment (Chloroquine-sensitive):
1000 mg (600 mg base) orally once, then 500 mg (300 mg base) orally 6 hours later, then 500 mg (300 mg base) orally once daily for 2 days (total 2500 mg over 3 days).
Malaria Prophylaxis (Chloroquine-sensitive):
500 mg (300 mg base) orally once weekly, starting 1-2 weeks before exposure and continuing for 4 weeks after leaving endemic area.
Rheumatoid Arthritis:
250 mg (150 mg base) orally once daily, or 500 mg (300 mg base) orally once daily if tolerated, not to exceed 2.5 mg/kg/day (base weight).
Systemic Lupus Erythematosus:
250 mg (150 mg base) orally once daily, or 500 mg (300 mg base) orally once daily if tolerated, not to exceed 2.5 mg/kg/day (base weight).
Pediatric Dosing
Neonatal:
Not established for routine use; use with extreme caution if at all.
Infant:
Malaria treatment (chloroquine-sensitive): 10 mg base/kg orally initially, then 5 mg base/kg orally 6 hours later, then 5 mg base/kg orally once daily for 2 days (total 25 mg base/kg over 3 days). Max 1000 mg initial dose. Malaria prophylaxis: 5 mg base/kg orally once weekly, not to exceed adult dose.
Child:
Malaria treatment (chloroquine-sensitive): 10 mg base/kg orally initially, then 5 mg base/kg orally 6 hours later, then 5 mg base/kg orally once daily for 2 days (total 25 mg base/kg over 3 days). Max 1000 mg initial dose. Malaria prophylaxis: 5 mg base/kg orally once weekly, not to exceed adult dose. For RA/Lupus: Not typically first-line, but if used, dose based on weight, not to exceed 2.5 mg/kg/day (base weight).
Adolescent:
Same as adult dosing for malaria prophylaxis/treatment. For RA/Lupus: Same as adult dosing, not to exceed 2.5 mg/kg/day (base weight).
Dose Adjustments
Renal Impairment:
Mild:
No specific adjustment generally required, but monitor closely.
Moderate:
Reduce dose by 25-50% or extend dosing interval. Monitor for toxicity.
Severe:
Reduce dose by 50% or more, or extend dosing interval significantly. Avoid if possible. Monitor for toxicity.
Dialysis:
Chloroquine is not significantly removed by hemodialysis. Dose adjustment needed based on residual renal function. Administer after dialysis.
Hepatic Impairment:
Mild:
No specific adjustment generally required.
Moderate:
Use with caution; consider dose reduction and monitor for toxicity, especially with severe liver disease.
Severe:
Use with extreme caution; significant dose reduction may be necessary. Avoid if possible due to extensive hepatic metabolism.
Pharmacology
Mechanism of Action
Chloroquine is a 4-aminoquinoline that concentrates in the acidic food vacuoles of Plasmodium parasites. It inhibits the parasite's heme polymerase, preventing the detoxification of heme (a byproduct of hemoglobin digestion) into hemozoin. This leads to the accumulation of toxic heme, which disrupts parasite metabolism and causes parasite death. In autoimmune conditions, its mechanism is less clear but involves immunomodulatory effects, including interference with antigen presentation, inhibition of lysosomal activity, and anti-inflammatory properties.
Pharmacokinetics
Absorption:
Bioavailability:
Approximately 89%
Tmax:
3-10 hours (for parent drug)
FoodEffect:
Food may increase absorption and reduce gastrointestinal upset.
Distribution:
Vd:
Extremely large (100-1000 L/kg), indicating extensive tissue binding and accumulation.
ProteinBinding:
Approximately 55%
CnssPenetration:
Limited, but can cross the blood-brain barrier to some extent, especially in overdose.
Elimination:
HalfLife:
Terminal half-life is highly variable, ranging from 3-5 days to 1-2 months (due to slow release from tissues).
Clearance:
Highly variable, dependent on renal and hepatic function.
ExcretionRoute:
Primarily renal (50-70% unchanged), with some hepatic metabolism and biliary excretion.
Unchanged:
50-70%
Pharmacodynamics
OnsetOfAction:
Hours to days for antimalarial effect; weeks to months for anti-inflammatory/DMARD effect.
PeakEffect:
Days for antimalarial effect; 3-6 months for full DMARD effect.
DurationOfAction:
Weeks to months due to long half-life and tissue accumulation.
Safety & Warnings
Side Effects
Urgent Side Effects: Seek Medical Help Right Away
Although rare, this medication can cause severe and potentially life-threatening side effects. If you experience any of the following symptoms, contact your doctor or seek medical attention immediately:
Signs of an allergic reaction: rash, hives, itching, red, swollen, blistered, or peeling skin (with or without fever), wheezing, tightness in the chest or throat, trouble breathing, swallowing, or talking, unusual hoarseness, or swelling of the mouth, face, lips, tongue, or throat
Signs of liver problems: dark urine, tiredness, decreased appetite, upset stomach or stomach pain, light-colored stools, vomiting, or yellow skin or eyes
Signs of low blood sugar: dizziness, headache, feeling sleepy, feeling weak, shaking, fast heartbeat, confusion, hunger, or sweating
Trouble controlling body movements, restlessness, seizures, mood changes, or changes in behavior
Trouble sleeping, feeling confused, hallucinations (seeing or hearing things that are not there), changes in hearing, or ringing in the ears
Muscle pain or weakness, burning, numbness, or tingling sensations that are not normal
Fever, chills, sore throat, unexplained bruising or bleeding, or feeling very tired or weak
Severe skin reactions (Stevens-Johnson syndrome/toxic epidermal necrolysis): red, swollen, blistered, or peeling skin (with or without fever), red or irritated eyes, or sores in the mouth, throat, nose, or eyes
Heart problems: fast or abnormal heartbeat, severe dizziness or passing out, shortness of breath, significant weight gain, or swelling in the arms or legs
Other Possible Side Effects
Like all medications, this drug can cause side effects. While many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects, contact your doctor or seek medical attention if they bother you or do not go away:
Stomach pain or cramps
Decreased appetite
Diarrhea, upset stomach, or vomiting
Headache
Changes in skin color
Changes in hair color
Hair loss
Reporting Side Effects
This list is not exhaustive, and you may experience other side effects. If you have questions or concerns, contact your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Although rare, this medication can cause severe and potentially life-threatening side effects. If you experience any of the following symptoms, contact your doctor or seek medical attention immediately:
Signs of an allergic reaction: rash, hives, itching, red, swollen, blistered, or peeling skin (with or without fever), wheezing, tightness in the chest or throat, trouble breathing, swallowing, or talking, unusual hoarseness, or swelling of the mouth, face, lips, tongue, or throat
Signs of liver problems: dark urine, tiredness, decreased appetite, upset stomach or stomach pain, light-colored stools, vomiting, or yellow skin or eyes
Signs of low blood sugar: dizziness, headache, feeling sleepy, feeling weak, shaking, fast heartbeat, confusion, hunger, or sweating
Trouble controlling body movements, restlessness, seizures, mood changes, or changes in behavior
Trouble sleeping, feeling confused, hallucinations (seeing or hearing things that are not there), changes in hearing, or ringing in the ears
Muscle pain or weakness, burning, numbness, or tingling sensations that are not normal
Fever, chills, sore throat, unexplained bruising or bleeding, or feeling very tired or weak
Severe skin reactions (Stevens-Johnson syndrome/toxic epidermal necrolysis): red, swollen, blistered, or peeling skin (with or without fever), red or irritated eyes, or sores in the mouth, throat, nose, or eyes
Heart problems: fast or abnormal heartbeat, severe dizziness or passing out, shortness of breath, significant weight gain, or swelling in the arms or legs
Other Possible Side Effects
Like all medications, this drug can cause side effects. While many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects, contact your doctor or seek medical attention if they bother you or do not go away:
Stomach pain or cramps
Decreased appetite
Diarrhea, upset stomach, or vomiting
Headache
Changes in skin color
Changes in hair color
Hair loss
Reporting Side Effects
This list is not exhaustive, and you may experience other side effects. If you have questions or concerns, contact your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Seek Immediate Medical Attention If You Experience:
- Blurred vision, difficulty reading, blind spots, halos around lights, or changes in color vision (especially red-green)
- Muscle weakness or difficulty walking
- Hearing loss or ringing in the ears (tinnitus)
- Severe dizziness or fainting spells
- Unusual bruising or bleeding, persistent sore throat, or fever (signs of blood problems)
- Severe nausea, vomiting, or diarrhea
- Skin rash, itching, or unusual skin discoloration
- Hair loss
- Any new or worsening heart palpitations or chest pain
Before Using This Medicine
Before Taking This Medication: Important Information to Share with Your Doctor
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction and its symptoms.
If you have experienced any changes in your vision or eye health.
If you have been diagnosed with certain medical conditions, including porphyria or psoriasis.
If you are currently taking any of the following medications: cimetidine or tamoxifen.
Please note that this is not an exhaustive list of potential interactions. To ensure your safety, it is crucial to disclose all of your medications, including prescription and over-the-counter drugs, natural products, and vitamins, as well as any existing health problems, to your doctor and pharmacist. They will help you determine whether it is safe to take this medication in conjunction with your other treatments. Never start, stop, or adjust the dosage of any medication without first consulting your doctor.
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction and its symptoms.
If you have experienced any changes in your vision or eye health.
If you have been diagnosed with certain medical conditions, including porphyria or psoriasis.
If you are currently taking any of the following medications: cimetidine or tamoxifen.
Please note that this is not an exhaustive list of potential interactions. To ensure your safety, it is crucial to disclose all of your medications, including prescription and over-the-counter drugs, natural products, and vitamins, as well as any existing health problems, to your doctor and pharmacist. They will help you determine whether it is safe to take this medication in conjunction with your other treatments. Never start, stop, or adjust the dosage of any medication without first consulting your doctor.
Precautions & Cautions
Important Warnings and Cautions
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication.
Severe Eye Problems
This medication can cause a severe eye problem, which may lead to permanent vision loss. The risk is higher if you have pre-existing eye or kidney problems, take high doses of this medication, use it for more than 5 years, or take certain other medications like tamoxifen. If you experience any changes in your vision, such as blurred or foggy vision, difficulty focusing or reading, or trouble seeing in low light, contact your doctor immediately. Additionally, if you lose part of your vision, see dark spots, or have a limited field of vision, seek medical attention right away. Regular eye exams are crucial, as directed by your doctor.
Low G6PD Levels
If you have low levels of the enzyme G6PD, you may be at risk of developing anemia. This condition is more common in individuals of African, South Asian, Middle Eastern, and Mediterranean descent. Regular blood tests are necessary to monitor your condition while taking this medication.
Long-Term Use and Blood Work
If you are taking this medication for an extended period, your doctor may recommend regular blood tests to monitor your condition. It is also essential to discuss your alcohol consumption with your doctor.
Interactions with Other Medications
When taking other medications, it is crucial to take them at a different time than this medication. Consult your doctor or pharmacist to determine the best schedule for your medications.
Sun Sensitivity
This medication can increase your risk of sunburn. Take precautions when spending time outdoors, and inform your doctor if you experience excessive sunburn.
Low Blood Sugar
This medication can cause low blood sugar, which can be life-threatening in severe cases. Monitor your blood sugar levels as directed by your doctor and seek medical attention if you experience any symptoms.
Severe and Potentially Deadly Reaction
In rare cases, this medication can cause a severe and potentially deadly reaction, characterized by fever, rash, swollen glands, and organ problems (such as liver, kidney, blood, heart, muscle, and joint, or lung issues). If you have any concerns or questions, discuss them with your doctor.
Cancer Risk
This medication may increase the risk of developing certain types of cancer. Discuss the benefits and risks with your doctor.
Accidental Exposure
Keep this medication out of reach of children, as accidental exposure can be fatal. If a child ingests this medication, seek medical attention immediately.
Age-Related Precautions
If you are 65 or older, use this medication with caution, as you may be more susceptible to side effects.
Pregnancy and Breastfeeding
Inform your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. Your doctor will discuss the benefits and risks of taking this medication with you.
Malaria Prevention
When using this medication to prevent malaria, it is essential to take additional precautions, including:
Using screens and bed netting
Applying insect repellent (10% to 35% DEET) and permethrin spray on clothing and nets
Avoiding spraying insect repellents on children
Reducing outdoor activities during evening and nighttime hours
If you experience a fever while in or after leaving a malaria-infested area, contact your doctor immediately. If you are pregnant and traveling to a malaria-infested area, discuss the risks with your doctor before taking this medication.
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication.
Severe Eye Problems
This medication can cause a severe eye problem, which may lead to permanent vision loss. The risk is higher if you have pre-existing eye or kidney problems, take high doses of this medication, use it for more than 5 years, or take certain other medications like tamoxifen. If you experience any changes in your vision, such as blurred or foggy vision, difficulty focusing or reading, or trouble seeing in low light, contact your doctor immediately. Additionally, if you lose part of your vision, see dark spots, or have a limited field of vision, seek medical attention right away. Regular eye exams are crucial, as directed by your doctor.
Low G6PD Levels
If you have low levels of the enzyme G6PD, you may be at risk of developing anemia. This condition is more common in individuals of African, South Asian, Middle Eastern, and Mediterranean descent. Regular blood tests are necessary to monitor your condition while taking this medication.
Long-Term Use and Blood Work
If you are taking this medication for an extended period, your doctor may recommend regular blood tests to monitor your condition. It is also essential to discuss your alcohol consumption with your doctor.
Interactions with Other Medications
When taking other medications, it is crucial to take them at a different time than this medication. Consult your doctor or pharmacist to determine the best schedule for your medications.
Sun Sensitivity
This medication can increase your risk of sunburn. Take precautions when spending time outdoors, and inform your doctor if you experience excessive sunburn.
Low Blood Sugar
This medication can cause low blood sugar, which can be life-threatening in severe cases. Monitor your blood sugar levels as directed by your doctor and seek medical attention if you experience any symptoms.
Severe and Potentially Deadly Reaction
In rare cases, this medication can cause a severe and potentially deadly reaction, characterized by fever, rash, swollen glands, and organ problems (such as liver, kidney, blood, heart, muscle, and joint, or lung issues). If you have any concerns or questions, discuss them with your doctor.
Cancer Risk
This medication may increase the risk of developing certain types of cancer. Discuss the benefits and risks with your doctor.
Accidental Exposure
Keep this medication out of reach of children, as accidental exposure can be fatal. If a child ingests this medication, seek medical attention immediately.
Age-Related Precautions
If you are 65 or older, use this medication with caution, as you may be more susceptible to side effects.
Pregnancy and Breastfeeding
Inform your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. Your doctor will discuss the benefits and risks of taking this medication with you.
Malaria Prevention
When using this medication to prevent malaria, it is essential to take additional precautions, including:
Using screens and bed netting
Applying insect repellent (10% to 35% DEET) and permethrin spray on clothing and nets
Avoiding spraying insect repellents on children
Reducing outdoor activities during evening and nighttime hours
If you experience a fever while in or after leaving a malaria-infested area, contact your doctor immediately. If you are pregnant and traveling to a malaria-infested area, discuss the risks with your doctor before taking this medication.
Overdose Information
Overdose Symptoms:
- Headache
- Drowsiness
- Visual disturbances (blurred vision, temporary blindness)
- Nausea, vomiting
- Hypotension (low blood pressure)
- Cardiac arrhythmias (irregular heartbeat, including QT prolongation, Torsades de Pointes, ventricular fibrillation)
- Cardiovascular collapse
- Seizures
- Respiratory depression
- Coma
- Death
What to Do:
Seek immediate emergency medical attention. Call 911 or your local poison control center (1-800-222-1222). Management includes gastric lavage, activated charcoal, supportive care for cardiovascular and respiratory function, and potentially vasopressors or antiarrhythmics.
Drug Interactions
Contraindicated Interactions
- Not typically contraindicated with specific drugs, but caution with drugs that prolong QT interval or cause retinopathy.
Major Interactions
- Amiodarone (increased risk of QT prolongation and arrhythmias)
- Mefloquine (increased risk of seizures, ECG abnormalities, and neuropsychiatric events)
- Digoxin (increased digoxin levels, monitor for toxicity)
- Cyclosporine (increased cyclosporine levels, monitor for toxicity)
- QT-prolonging drugs (e.g., Class IA and III antiarrhythmics, antipsychotics, tricyclic antidepressants, macrolide antibiotics, fluoroquinolones) - increased risk of Torsades de Pointes.
- Antacids containing aluminum or magnesium (decreased chloroquine absorption, separate administration by at least 4 hours).
Moderate Interactions
- Cimetidine (may inhibit chloroquine metabolism, increasing levels)
- Praziquantel (may decrease praziquantel levels, reducing efficacy)
- Ampicillin (decreased ampicillin absorption, separate administration)
- Vaccines (live attenuated vaccines may have reduced efficacy if chloroquine is used for immunosuppressive purposes, though less common than with other DMARDs).
Minor Interactions
- Not available
Monitoring
Baseline Monitoring
Ophthalmic examination (visual acuity, fundoscopy, visual fields, OCT)
Rationale: To establish baseline and detect pre-existing retinopathy, as chloroquine can cause irreversible retinal damage.
Timing: Before initiating therapy.
Electrocardiogram (ECG)
Rationale: To assess baseline cardiac rhythm and QT interval, as chloroquine can prolong QT interval and cause arrhythmias.
Timing: Before initiating therapy.
Complete Blood Count (CBC)
Rationale: To assess for baseline hematologic abnormalities, as chloroquine can cause bone marrow suppression.
Timing: Before initiating therapy.
Liver Function Tests (LFTs)
Rationale: To assess baseline hepatic function, as chloroquine is metabolized by the liver.
Timing: Before initiating therapy.
Renal Function Tests (RFTs) / Creatinine Clearance
Rationale: To assess baseline renal function, as chloroquine is primarily renally excreted and dose adjustments may be needed.
Timing: Before initiating therapy.
Routine Monitoring
Ophthalmic examination (visual acuity, fundoscopy, visual fields, OCT)
Frequency: Annually after 5 years of therapy or if cumulative dose exceeds 1000g, or if patient has risk factors (renal impairment, liver disease, concomitant tamoxifen use, high body fat). More frequently if symptoms develop.
Target: Stable vision, no signs of retinopathy.
Action Threshold: Any new visual changes or signs of retinopathy; discontinue drug and refer to ophthalmologist.
Electrocardiogram (ECG)
Frequency: Periodically, especially if patient has cardiac risk factors or develops symptoms. More frequent monitoring if on high doses or concomitant QT-prolonging drugs.
Target: Normal sinus rhythm, QTc < 450 ms (men), < 470 ms (women).
Action Threshold: Significant QT prolongation (>500 ms or >60 ms increase from baseline), new arrhythmias; consider dose reduction or discontinuation.
Complete Blood Count (CBC)
Frequency: Periodically (e.g., every 3-6 months) during long-term therapy.
Target: Within normal limits.
Action Threshold: Significant cytopenias (e.g., leukopenia, thrombocytopenia, anemia); consider dose reduction or discontinuation.
Liver Function Tests (LFTs)
Frequency: Periodically (e.g., every 6-12 months) during long-term therapy.
Target: Within normal limits.
Action Threshold: Significant elevation of liver enzymes; investigate cause, consider dose reduction or discontinuation.
Renal Function Tests (RFTs)
Frequency: Periodically (e.g., every 6-12 months) during long-term therapy, or more frequently if renal impairment is present.
Target: Stable creatinine, eGFR.
Action Threshold: Significant decline in renal function; adjust dose accordingly.
Symptom Monitoring
- Visual disturbances (blurred vision, difficulty reading, halos, blind spots, color vision changes)
- Muscle weakness or atrophy
- Hearing loss or tinnitus
- Dizziness or vertigo
- Nausea, vomiting, diarrhea, abdominal cramps
- Skin rash, itching, pigmentation changes
- Hair loss
- Fatigue, malaise
- Signs of cardiac arrhythmias (palpitations, syncope, chest pain)
- Signs of bone marrow suppression (unexplained fever, sore throat, unusual bleeding/bruising)
Special Patient Groups
Pregnancy
Chloroquine crosses the placenta. For malaria prophylaxis and treatment, the benefits generally outweigh the risks, and it is considered safe and effective. For long-term use in autoimmune conditions, the risk-benefit should be carefully assessed, though it is often preferred over other DMARDs with higher known risks in pregnancy.
Trimester-Specific Risks:
First Trimester:
Generally considered safe for malaria prophylaxis/treatment. Limited data on long-term use for autoimmune conditions, but no clear evidence of teratogenicity.
Second Trimester:
Generally considered safe for malaria prophylaxis/treatment.
Third Trimester:
Generally considered safe for malaria prophylaxis/treatment.
Lactation
Chloroquine is excreted into breast milk in small amounts. The amount transferred to the infant is generally considered too low to be harmful or to provide effective malaria prophylaxis for the infant. It is generally considered compatible with breastfeeding at standard doses for malaria prophylaxis/treatment or autoimmune conditions.
Infant Risk:
Low risk. Monitor infant for gastrointestinal upset (diarrhea, vomiting) or rash, though these are rare.
Pediatric Use
Dosing is weight-based for malaria. For autoimmune conditions, hydroxychloroquine is generally preferred due to a better safety profile. Close monitoring for toxicity, especially ocular, is crucial.
Geriatric Use
Increased risk of toxicity (especially ocular and cardiac) due to age-related decline in renal and hepatic function, and potential for polypharmacy. Use with caution, consider lower doses, and monitor closely.
Clinical Information
Clinical Pearls
- Chloroquine has an extremely long half-life and accumulates in tissues, leading to cumulative toxicity, especially with long-term use.
- The most serious long-term toxicity is irreversible retinopathy, which can lead to blindness. Regular, comprehensive ophthalmic exams are critical, especially after 5 years of use or if cumulative dose is high.
- Cardiotoxicity, including QT prolongation and cardiomyopathy, is a significant risk, particularly with higher doses or in overdose. ECG monitoring is important.
- Chloroquine is dosed based on chloroquine base, not the salt form (e.g., chloroquine phosphate). 250 mg chloroquine phosphate contains 150 mg chloroquine base.
- Take with food to minimize GI upset.
- Resistance to chloroquine is widespread for Plasmodium falciparum, limiting its use for malaria treatment to sensitive strains. It remains effective for P. vivax, P. ovale, and P. malariae.
- Hydroxychloroquine is generally preferred over chloroquine for autoimmune conditions due to a better safety profile and lower risk of retinopathy.
Alternative Therapies
- Hydroxychloroquine (for autoimmune conditions, less toxic)
- Mefloquine (for malaria prophylaxis/treatment)
- Atovaquone/Proguanil (for malaria prophylaxis/treatment)
- Doxycycline (for malaria prophylaxis/treatment)
- Artemether/Lumefantrine (for malaria treatment)
- Primaquine (for P. vivax/ovale radical cure)
- Other DMARDs (e.g., Methotrexate, Sulfasalazine, Biologics for RA/Lupus)
Cost & Coverage
Average Cost:
$20 - $50 per 30 tablets
Generic Available:
Yes
Insurance Coverage:
Tier 1 or 2 (Generic)
General Drug Facts
If your symptoms or health issues persist or worsen, it is essential to contact your doctor promptly. To ensure safe and effective treatment, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so it's a good idea to check with your pharmacist for more information. If you have any questions or concerns about your medication, don't hesitate to reach out to your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek emergency medical attention. When seeking help, be prepared to provide details about the medication taken, the amount, and the time it happened.