Common uses of chloroquine
Chloroquine is primarily used to prevent and treat malaria caused by Plasmodium species that remain susceptible to chloroquine. Although resistance is common in many parts of the world, chloroquine continues to be a preferred option in certain geographic regions where surveillance data confirm sensitivity. It may be used for travelers’ malaria prophylaxis and for treatment of uncomplicated, chloroquine‑sensitive malaria infections as part of guideline‑based care.
Beyond malaria, chloroquine can be prescribed for extraintestinal amebiasis (amebic liver involvement) in combination with tissue‑acting agents when indicated. Historically, it has been used for certain dermatologic and rheumatologic conditions, but hydroxychloroquine often replaces it due to a more favorable safety profile. Notably, chloroquine is not recommended for the treatment or prevention of COVID‑19 under contemporary evidence‑based guidelines.
How chloroquine works (mechanism of action)
Chloroquine is a 4‑aminoquinoline that concentrates in parasite food vacuoles and raises intravacuolar pH. This interferes with the parasite’s ability to detoxify heme during hemoglobin metabolism, leading to accumulation of toxic heme products and parasite death. Its immunomodulatory effects likely stem from lysosomal alkalinization and interference with antigen processing, which explains some of its historical use in inflammatory disorders. The drug’s extensive tissue distribution and long half‑life underlie weekly dosing in prophylaxis regimens and the need for careful monitoring during longer courses.
Dosage and direction for chloroquine
Dosing depends on indication (malaria prophylaxis versus treatment, or amebiasis), patient age and weight, local resistance patterns, and the drug formulation (chloroquine base versus chloroquine phosphate salt). Because label strengths are expressed differently in various markets, dosing should always follow a clinician’s prescription and the specific product labeling to avoid conversion errors. For malaria prophylaxis, chloroquine is typically taken on a weekly schedule beginning in advance of travel, continued during travel, and for several weeks after return. For acute, chloroquine‑sensitive malaria, an initial loading schedule followed by additional doses within the first 48 hours is common. Amebiasis regimens usually require combination therapy and a defined course length.
Take chloroquine with food to reduce gastrointestinal upset. Do not crush or split tablets unless the product information allows it. If a dose is vomited shortly after ingestion, contact a clinician for advice on whether to redose. Never use chloroquine empirically for fever in a malaria‑endemic region without medical direction, as resistance patterns and species identification determine the right therapy. Children require weight‑based dosing; seek pediatric specialist guidance.
Precautions and monitoring
A baseline medical review is essential before starting chloroquine. Eye safety is a central concern: although clinically significant retinopathy is more associated with long‑term use, even shorter courses warrant attention in patients with preexisting macular disease or visual symptoms. Report any blurred vision, halos, photophobia, color vision changes, or difficulty focusing immediately. Periodic ophthalmologic evaluation is recommended for longer courses and for those with risk factors.
Cardiac risks include QT‑interval prolongation and cardiomyopathy. Patients with congenital long QT syndrome, prior torsades de pointes, uncompensated heart failure, cardiomyopathy, or electrolyte abnormalities (low potassium/magnesium) need careful risk‑benefit assessment. Consider baseline ECG in those with risk factors or co‑prescribed QT‑prolonging medications. Chloroquine can cause hypoglycemia; monitor glucose if you have diabetes or experience symptoms such as sweating, confusion, or palpitations. Use caution with hepatic or renal impairment, G6PD deficiency, seizure disorders, psoriasis, and porphyria. Avoid alcohol excess, which can worsen hepatic adverse effects.
Contraindications to chloroquine
Do not use chloroquine if you have a known hypersensitivity to chloroquine or other 4‑aminoquinolines. It is generally contraindicated in patients with preexisting retinopathy or significant visual field defects attributable to 4‑aminoquinolines. Avoid use in individuals with a history of serious ventricular arrhythmias or uncorrected QT prolongation. Severe psoriasis and porphyria can be exacerbated by chloroquine. Use is typically avoided or undertaken with specialist oversight in patients with epilepsy, significant hepatic or renal impairment, and in those with known cardiomyopathy.
Possible side effects of chloroquine
Common adverse effects include gastrointestinal upset (nausea, abdominal pain), decreased appetite, headache, dizziness, and pruritus (notably in some patients with darker skin). Visual disturbances such as blurred vision, difficulty focusing, or halos can occur and warrant prompt attention. Skin reactions may include rash, photosensitivity, and hair discoloration; rarely, severe dermatologic reactions such as Stevens–Johnson syndrome have been reported.
Neurologic and psychiatric reactions—insomnia, irritability, mood changes—are typically transient but can be serious in rare cases. Hypoglycemia may present with sweating, tremor, confusion, or fainting; this risk increases with concomitant antidiabetic therapy or prolonged fasting. Cardiovascular effects include palpitations, hypotension, QT prolongation, and, with prolonged use or high cumulative exposure, cardiomyopathy. Hematologic abnormalities (anemia, leukopenia), hepatic enzyme elevations, and myopathy or neuropathy can occur, especially with extended courses. Seek urgent medical care for signs of severe reaction: chest pain, syncope, severe rash, visual loss, seizures, or jaundice.
Chloroquine drug interactions
Chloroquine interacts with numerous medications. The most clinically significant involve cardiac rhythm, blood glucose, and drug absorption or metabolism. Avoid combining with other QT‑prolonging agents when possible—examples include certain antiarrhythmics (amiodarone, sotalol), macrolide antibiotics (azithromycin), fluoroquinolones (levofloxacin), antipsychotics, and some antidepressants. If coadministration is unavoidable, a risk‑mitigation strategy with ECG and electrolyte monitoring is recommended.
Chloroquine can enhance the effect of insulin and oral hypoglycemics, raising hypoglycemia risk. It can increase plasma levels of digoxin and cyclosporine; monitor levels if combined. Antacids and kaolin can reduce chloroquine absorption—separate administration by several hours. Cimetidine may elevate chloroquine concentrations; consider alternatives for acid suppression. Concomitant mefloquine may raise seizure risk and contribute to QT effects. Chloroquine can reduce praziquantel exposure and diminish the immunogenicity of intradermal rabies vaccination; follow vaccine‑specific guidance. Always provide a full medication and supplement list to your clinician and pharmacist before starting chloroquine.
Use in specific populations
Pregnancy: In chloroquine‑sensitive malaria regions, prophylaxis or treatment may be considered when the benefits outweigh risks; many guidelines prefer chloroquine over alternatives during pregnancy if sensitivity is confirmed. Consult obstetric and infectious disease specialists. Lactation: Chloroquine is excreted in breast milk in small amounts; discuss risks and benefits, noting that breastfeeding does not provide adequate infant prophylaxis or treatment.
Pediatrics: Children are particularly vulnerable to toxicity from dosing errors and overdose; weight‑based dosing and child‑resistant storage are critical. Geriatrics: Age‑related cardiac and ocular comorbidities increase risk; consider baseline ECG and eye assessment. Hepatic or renal impairment: Dose adjustments and closer monitoring may be needed due to altered clearance and increased toxicity risk.
Missed dose guidance
If you miss a dose, take it as soon as you remember unless it is close to your next scheduled dose. If it is near the time of the next dose, skip the missed dose and resume your regular schedule. Do not double up. For weekly prophylaxis, aim for the same day each week; if a dose is significantly delayed, contact your clinician for catch‑up advice.
Overdose: what to do
Chloroquine overdose is a medical emergency, especially in children, with rapid onset of seizures, profound hypotension, arrhythmias, and cardiac arrest. If an overdose is suspected, call emergency services and poison control immediately. Do not wait for symptoms to appear. Keep chloroquine strictly out of children’s reach and in child‑resistant containers; even small amounts can be fatal for a child.
Storage and handling
Store chloroquine at room temperature away from moisture, heat, and direct light. Keep tablets in the original, tightly closed container. Do not store in the bathroom. Secure all antimalarials out of sight and reach of children and pets. Dispose of unused or expired medication through take‑back programs; do not flush unless instructed by product labeling.
U.S. sale and prescription policy: buy chloroquine without prescription at HealthSouth Hospital of Altamonte Springs
In the United States, chloroquine is a prescription medication. However, modern care models allow lawful, structured access without a traditional paper prescription by integrating pharmacist protocols and telehealth evaluations. HealthSouth Hospital of Altamonte Springs offers a compliant pathway to buy chloroquine without prescription in the conventional sense by coordinating an online health questionnaire and, when indicated, a same‑day review by a licensed clinician or pharmacist operating under state‑authorized protocols. If appropriate, a valid prescription or protocol‑based order is generated and dispensed to you directly.
This approach preserves medical oversight—dose selection, interaction checks, and counseling—while removing barriers of in‑person appointments for straightforward cases like chloroquine‑sensitive malaria prophylaxis. Geographic eligibility, identity verification, and clinical criteria apply, and some requests may be redirected to in‑person care. Pricing is transparent, and shipping is trackable. To proceed, be prepared to share your travel itinerary, past medical history, medication list, and any prior eye or heart issues so the care team can ensure chloroquine is safe and appropriate in your situation.
