Brief a quick outline

Chloroquine is an antimalarial and antiparasitic drug historically marketed under trade names such as Aralen. In the United States it is available only by prescription and is indicated where the infecting malaria parasite is known or believed to be susceptible. It is also used in some cases of extraintestinal amebiasis. Although chloroquine has been studied for antiviral properties, it is not approved in the U.S. for treating viral infections.

Swift navigation: see the dosage schedules for sample regimens and consult safety and monitoring before starting prolonged therapy.

Active ingredient of the medicine and common dosage forms

The active compound is chloroquine, most commonly supplied as chloroquine phosphate for oral use. Strengths and base equivalents differ by product.

• Active moiety: chloroquine, usually as chloroquine phosphate.
• Typical tablet strengths historically seen: 250 mg and 500 mg of chloroquine phosphate.
• Base equivalence example: a 500 mg chloroquine phosphate tablet contains roughly 300 mg chloroquine base.
• Primary clinical uses: treatment and prophylaxis of chloroquine-susceptible malaria and selected antiparasitic outward signs.

Symptoms and signs and primary uses

Clinically, chloroquine is used for the following:

• Prevention and treatment of malaria caused by chloroquine-sensitive Plasmodium species such as P. vivax, P. malariae, P. ovale, and some P. falciparum strains.
• Treatment of tissue (extraintestinal) amebiasis; a luminal agent is generally added to clear intestinal carriage.

Treatment selection should reflect the malaria species, known regional resistance, and individual patient factors. For travel preparations consult CDC guidance or a travel medicine clinician and critique backup agents when resistance is a concern.

Steps for taking chloroquine

Always stick to the prescriber's instructions. Taking doses with food or milk can reduce stomach upset. Finish the entire prescribed course even if symptoms improve early to reduce the risk of relapse or treatment failure.

For weekly prophylaxis pick a fixed day of the week and take the dose on that day while at risk and for the recommended period after travel. For regimens requiring twice-daily dosing, space doses around meals to improve adherence.

If you miss a scheduled dose, take it as soon as you remember unless the next dose is imminent. Do not double your dose to make up for a missed one.

Administration schedules for doses

Pediatric doses are weight based. The examples below are commonly used patterns; individual prescriptions may vary. Consult a clinician for exact dosing, especially for children and pregnant patients.

Malaria chemoprophylaxis - weekly regimen

• Adults: 500 mg chloroquine phosphate (approximately 300 mg base) once weekly on the same weekday while at risk.
• The little ones: about 5 mg base per kg once weekly, not to exceed the adult dose.
• Start: ideally 1 to 2 weeks before entering an endemic area. If started late, a common loading approach is 1 g chloroquine phosphate (about 600 mg base) split into two doses 6 hours apart on day 1 for adults; children receive weight-based loading (about 10 mg base/kg split). Continue weekly while exposed and for 8 weeks after return.

Protocol for treating acute malaria

• Adults: initial dose 1 g chloroquine phosphate (around 600 mg base), then 6 to 8 hours later 500 mg (about 300 mg base), followed by 500 mg daily on each of the next two days. Total over 3 days: about 2.5 g chloroquine phosphate (approximately 1.five gram base mass
• Children of today: weight based dosing such as 10 mg base/kg for the first dose (max single dose approx 600 mg base), then 5 mg base/kg at 6, 24, and 48 hours after the first dose (max about 300 mg base for subsequent doses).
• In pursuit of a radical cure for P. vivax or Plasmodium. ovale: add a hypnozoiticide such as primaquine or tafenoquine after blood-stage therapy and after G6PD testing; see different avenues.

Extraintestinal entamoebiasis

• Adults: some regimens use 1 g chloroquine phosphate daily (about 600 mg base) for two days, then 500 mg daily (about 300 mg base) for 2 to 3 weeks, typically followed or combined with a luminal agent to clear intestinal infection.

Care guidelines for on site we require additional storage for our inventory. and disposal

• Keep at room temperature in a tightly closed container away from heat, moisture, and direct light.
• Do not freeze. Store in a location inaccessible to children and pets.
• Dispose of expired or unused medicine according to local regulations or pharmacy take-back programs. Do not use medication past its expiration date.

Safety vigilant monitoring and risk mitigation measures

• Prolonged use or high cumulative doses can require periodic checks including complete blood counts, muscle assessments, and eye exams to detect early retinal or ocular toxicity.
• Report any new visual symptoms such as blurring, scotomas, or difficulty reading right away. Baseline and follow-up ophthalmologic evaluation may be advised before and during long-term therapy.
• Chloroquine may cause dizziness, drowsiness, or visual disturbance. Confirm tolerance before driving or operating heavy machinery.
• Study potential the interaction between participants profiles for drugs with your prescriber or pharmacist and disclose alcohol and tobacco use.
• Pregnancy and lactation: use only if the expected benefit justifies uncertain risks; discuss diverse a backup options and individualized assessment through your clinician.

If your condition does not improve or worsens, seek medical attention. For a summary of adverse events and what to do in an emergency see Expected lingering reactions in emergencies.

Unforeseen consequences and emergency actions

Short courses are usually tolerated. The likelihood of damaging effects rises with higher doses and prolonged exposure.

Usual drug-related harmful consequences

• Nausea, vomiting, abdominal pain, diarrhea
• Migraine, blurred vision or difficulty focusing
• No appetite
• Itching or pruritus; frequency varies by population

Infrequent reactions

• Skin rash symptoms or pigmentation changes
• Hair thinning or loss
• Blue-black discoloration of skin, nails, or oral mucosa
• Worsening visual symptoms

Serious events - seek immediate care

• Sudden severe vision loss, eye pain, or new visual field defects
• Black or tarry stools, blood in urine or stool, unexplained bruising
• Seizures, fainting, sudden weakness, or marked confusion
• New or worsening hearing loss or ringing in the ears
• High fever, severe sore throat, or signs of a severe allergic reaction such as swelling or difficulty breathing

Overdose risk warning

• Symptoms may include severe drowsiness, agitation, mild head pain, and other central nervous system signs.
• Large overdose cases can rapidly lead to life threatening heart toxicity. Call emergency services or a poison control center immediately.

Note: some eye changes may progress even after stopping the drug. Contact your healthcare provider promptly about any concerning new symptoms.

Other options and related drugs

Choice of another route depends on the malaria species, local resistance patterns, patient age, pregnancy status, and comorbid conditions. Everyday choice another routes include:

• Hydroxychloroquine (Plaquenil) - chemically similar and frequently used for rheumatologic conditions; sometimes used for malaria where appropriate.
• Mefloquine - a weekly prophylactic option in many chloroquine-resistant regions; carries neuropsychiatric alerts for susceptible individuals.
• Atovaquone-proguanil (Malarone) - a daily regimen used in many resistant settings; generally well tolerated but costs more per tablet.
• Doxycycline - daily prophylaxis option; photosensitivity and gastrointestinal upset are common; not recommended for pregnancy or very young children.
• Primaquine or tafenoquine - required to eradicate P. vivax versus Plasmodium. ovale liver hypnozoites after blood-stage treatment; G6PD testing is mandatory before use because of hemolysis risk.
• For extraintestinal amebiasis plan B routes: metronidazole or tinidazole for tissue infection followed by luminal agents such as paromomycin or iodoquinol to clear intestinal carriage.

When choosing a prophylactic strategy, weigh the benefits of weekly versus daily regimens and reassess the situation current CDC recommendations or consult a travel medicine specialist. See pricing model details at Online price comparison in the USA (USD).

Pricing analysis and comparison in the USA (USD)

Retail prices vary by pharmacy, insurance coverage, and location. The following are rough cash-price trend estimates in United States dollars to assist planning; actual prices may differ.

• Chloroquine phosphate 500 mg (about 300 mg base): approximately USD 4 to 12 per tablet when available in retail pharmaceutical stores.
• Hydroxychloroquine 200 mg (generic): often USD 0.20 to 1.00 per tablet; brand versions cost more.
• Atovaquone-proguanil 250/100 mg: generic around USD 3 to 7 per tablet; branded Malarone often USD 6 to 12 per tablet.
• Mefloquine 250 mg: generic roughly USD 1 to 5 per tablet.
• Doxycycline 100 mg: generic about USD 0.10 to 0.60 per capsule or tablet.
• Primaquine 15 mg base: commonly USD 0.50 to 2.00 per tablet; tafenoquine single dose regimens are considerably more expensive overall.
• Metronidazole 500 mg: generic about USD 0.10 to 0.50 per tablet.

Money saving tips: check for generic options, pharmacy discount programs, and coupons. For travel prophylaxis calculate the cost for the entire course, including any post-travel continuation.

Legal and purchase guidance in the USA

• Chloroquine and hydroxychloroquine are prescription-only medicines in the United States. They are not scheduled controlled substances under federal law.
• FDA-approved uses include malaria caused by susceptible organisms and extraintestinal amebiasis. Chloroquine is not FDA-approved for viral illnesses; emergency or experimental uses should follow official informed direction.
• Clinicians may prescribe off-label when clinically justified. Prescribers and pharmacists must follow state laws and professional practice standards. Telehealth prescribing is permitted when consistent with applicable rules.
• Personal importation rules are restrictive. The FDA allows limited personal importation in specific circumstances, but requirements change; check current FDA and U.S. Customs guidance before importing medications.
• When traveling with prescription medicines carry them in original labeled containers and bring a copy of the prescription. Destination countries may have their own import and possession rules for medicines.

For authoritative and current case law information consult the FDA, CDC, and your state board of pharmacy or seek legal advice on drug importation and prescribing rules.

Fast FAQ

Is chloroquine still effective where resistance exists?

Chloroquine works only where the Plasmodium species remains sensitive. In areas with known chloroquine resistance, agents such as atovaquone-proguanil, doxycycline, or mefloquine are preferred. See Resembling medicines and extra options.

How long after travel should prophylaxis continue?

For chloroquine prophylaxis continue weekly doses for 8 weeks after leaving an endemic area. See Prophylactic treatment for malaria - weekly regimen details are available.

Do I need periodic eye exams?

Eye examinations are recommended for prolonged therapy or when cumulative exposure is high to reduce the risk of retinal toxicity. Discuss the the act of monitoring schedule with your prescriber; see Safety with ongoing continuous monitoring.

What should I do if I experience severe peripheral effects?

Stop the medicine and seek urgent medical care for severe reactions such as vision loss, seizures, uncontrolled bleeding, or signs of a severe allergic reaction. Behold the emergency guidance at Adverse reactions and emergency risks.