Chloroquine

What is Chloroquine?

• Chloroquine (Aralen), is a 4-aminoquinoline, is an anti-protozoal agent.

Chloroquine

What are the uses of this medicine?

Chloroquine (Aralen), is indicated for the:

• Treatment of uncomplicated malaria due to susceptible strains of P. falciparum, P.malariae, P. ovale, and P.vivax.
• Prophylaxis of malaria in geographic areas where resistance to chloroquine is not present.
• Treatment of extraintestinal amebiasis.

Chloroquine molecule ball

Limitations of Use in Malaria:

• Do not use chloroquine phosphate tablets for the treatment of complicated malaria (high-grade parasitemia and/or complications e.g., cerebral malaria or acute renal failure).
• Do not use chloroquine phosphate tablets for malaria prophylaxis in areas where chloroquine resistance occurs, Resistance to chloroquine phosphate tablets is widespread in P. falciparum, and is reported in P.vivax .
• Concomitant therapy with an 8-aminoquinoline drug is necessary for treatment of the hypnozoite liver stage forms of P.vivax and P.ovale.

Chloroquine 3D structure

How does this medicine work?

• The phosphate salt of chloroquine, a quinoline compound with antimalarial and anti-inflammatory properties.
• Chloroquine is the most widely used drug against malaria, except for those cases caused by chloroquine resistant Plasmodium falciparum.
• Although the mechanism of action is not fully understood, chloroquine is shown to inhibit the parasitic enzyme heme polymerase that converts the toxic heme into non-toxic hemazoin, thereby resulting in the accumulation of toxic heme within the parasite.
• Chloroquine may also interfere with the biosynthesis of nucleic acids.
• It can also inhibit certain enzymes by its interaction with DNA.

• Chloroquine is active against the erythrocytic forms of susceptible strains of Plasmodium falciparum, Plasmodium malariae, Plasmodium ovale, and Plasmodium vivax.
• Chloroquine is not active against the gametocytes and the exoerythrocytic forms including the hypnozoite stage (P. vivax and P. ovale) of the Plasmodium parasites.

Who Should Not Use this medicine ?

This medicine cannot be used in patients:

• with known hypersensitivity to 4-aminoquinoline compounds.
• with retinal or visual field changes of any etiology.

What drug interactions can this medicine cause?

• Tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take.

Be sure to mention any of the following:

• acetaminophen (Tylenol, others)
• azithromycin (Zithromax)
• cimetidine (Tagamet)
• cyclosporine (Gengraf, Neoral, Sandimmune)
• insulin and oral medications for diabetes
• medications for seizures such as carbamazepine (Carbatrol, Epitol, Equetro, Tegretol, Teril), phenytoin (Dilantin, Phenytek), or valproic acid (Depakene)
• certain medications for irregular heartbeat such as amiodarone (Pacerone)
• methotrexate (Trexall, Xatmep)
• moxifloxacin (Avelox)
• praziquantel (Biltricide)
• tamoxifen (Nolvadex)

• If you are taking antacids, take them 4 hours before or 4 hours after chloroquine.
• If you are taking ampicillin, take it at least 2 hours before or 2 hours after chloroquine.

Is this medicine FDA approved?

• It was approved for medical use in the United States in 1966. It is available as a generic medication.

How should this medicine be used?

• Each 500 mg tablet of Chloroquine phosphate contains the equivalent of 300 mg chloroquine base. In infants and children the dosage is preferably calculated by body weight.

Recommended dosage:

As Prophylaxis against chloroquine-sensitive Plasmodium species:

• Adult Dose: The dosage for prophylaxis is 500 mg (= 300 mg base) administered once per week on exactly the same day of each week.
• Pediatric Dose: The dosage for prophylaxis is 5 mg calculated as base, per kg of body weight, administered once per week on exactly the same day of each week. The pediatric dose should never exceed the adult dose regardless of weight.

For Treatment of uncomplicated malaria due to chloroquine-sensitive Plasmodium species:

• Adults: An initial dose of 1 g salt (= 600 mg base) followed by an additional 500 mg (= 300 mg base) after six to eight hours and a single dose of 500 mg (= 300 mg base) on each of two consecutive days. This represents a total dose of 2.5 g chloroquine phosphate or 1.5 g base in three days.
• Infants and Children: In infants and children, the recommended dose is 10 mg base/kg followed by 5 mg based/kg at 6, 24 and 36 hours (total dose 25 mg based/kg). The pediatric dose should never exceed the adult dose regardless of weight.

For P. vivax and P. ovale:

• Concomitant therapy with an 8-aminoquinoline compound is necessary for treatment of the hypnozoite liver stage forms of the parasites.

For Extraintestinal Amebiasis: Adults Dosage:

• 1 g salt (600 mg base) daily for two days, followed by 500 mg (300 mg base) daily for at least two to three weeks.
• Treatment is usually combined with an effective intestinal amebicide.

Administration:

• Chloroquine phosphate comes as a tablet to take by mouth.
• For prevention of malaria in adults, one dose is usually taken once a week on exactly the same day of the week.
• Your doctor will tell you how many tablets to take for each dose.
• One dose is taken beginning 2 weeks before traveling to an area where malaria is common, while you are in the area, and then for 8 weeks after you return from the area.
• If you are unable to start taking chloroquine for 2 weeks before traveling, your doctor may tell you to take double the dose right away.
• For treatment of sudden, severe attacks of malaria in adults, one dose is usually taken right away, followed by half the dose 6 to 8 hours later and then half the dose once a day for the next 2 days.
• For prevention and treatment of malaria in infants and children, the amount of chloroquine phosphate is based on the child's weight.
• Your doctor will calculate this amount and tell you how much chloroquine phosphate your child should receive.
• For treatment of amebiasis, one dose is usually taken for 2 days and then half the dose every day for 2 to 3 weeks.
• It is usually taken in combination with other amebicides.
• Chloroquine phosphate may cause an upset stomach.
• Take chloroquine phosphate with food.

What are the dosage forms and brand names of this medicine?

This medicine is available in fallowing doasage form:

• As Tablets containing 500 mg chloroquine phosphate USP, equivalent to 300 mg of chloroquine base

This medicine is available in fallowing brand namesː

• Aralen

What side effects can this medication cause?

The most common side effects of this medicine may include:

• headache
• nausea
• loss of appetite
• diarrhea
• upset stomach
• stomach pain
• rash
• itching
• hair loss

Less common, but serious side effects may include:

• Ocular disorders
• Immune system disorders
• Ear and labyrinth disorders
• Musculoskeletal and connective tissue-disorders
• Gastrointestinal disorders
• Skin and subcutaneous tissue disorders
• Blood and lymphatic system disorders
• Nervous system disorders
• Neuropsychiatric disorders
• Cardiac disorders
• Metabolic and Nutritional disorders

What special precautions should I follow?

• Chloroquine phosphate tablets are not effective against chloroquine-or hydroxychloroquine-resistant strains of Plasmodium species. Chloroquine resistance is widespread in P. falciparum and is reported in P. vivax. Patients infected with a resistant strain of plasmodia should be treated with another form of antimalarial therapy.
• Chloroquine does not treat the hypnozoite liver stage forms of Plasmodium and will therefore not prevent relapses of malaria due to P. vivax or P. ovale. Additional treatment with an anti-malarial agent active against these forms, such as an 8-aminoquinoline, is required for the treatment of infections with P. vivax and P. ovale.
• Cases of cardiomyopathy resulting in cardiac failure, in some cases with fatal outcome, have been reported.
• Chloroquine should be used with caution in patients with cardiac disease, a history of ventricular arrhythmias, uncorrected hypokalemia and/or hypomagnesemia, or bradycardia (<50 bpm), and during concomitant administration with QT interval prolonging agents due to potential for QT interval prolongation.
• Chloroquine has been shown to cause severe hypoglycemia including loss of consciousness that could be life-threatening in patients treated with or without antidiabetic medications. Patients presenting with clinical symptoms suggestive of hypoglycemia during treatment with chloroquine should have their blood glucose level checked and treatment reviewed as necessary.
• Irreversible retinal damage has been observed in some patients who had received chloroquine. It is recommended that chloroquine be discontinued if ocular toxicity is suspected.
• Acute extrapyramidal disorders may occur with chloroquine. These adverse reactions usually resolve after treatment discontinuation and/or symptomatic treatment.
• All patients on long-term therapy with chloroquine should be questioned and examined periodically, including testing knee and ankle reflexes, to detect any evidence of muscular weakness. If weakness occurs, discontinue the drug.
• Use of chloroquine phosphate tablets in patients with psoriasis may precipitate a severe attack of psoriasis. Chloroquine phosphate tablets should not be used in these conditions unless the benefit to the patient outweighs the potential risks.
• Complete blood cell counts should be checked periodically if patients are given prolonged therapy.
• Chloroquine may cause hemolysis in glucose-6 phosphate dehydrogenase (G-6-PD) deficiency. Blood monitoring may be needed as hemolytic anemia may occur.
• In patients with preexisting auditory damage, chloroquine should be administered with caution.
• Since chloroquine phosphate tablets are known to concentrate in the liver, it should be used with caution in patients with hepatic disease or alcoholism or in conjunction with known hepatotoxic drugs.
• Chloroquine may increase the risk of convulsions in patients with a history of epilepsy.
• Because of the potential for serious adverse reactions in nursing infants from chloroquine, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the potential clinical benefit of the drug to the mother.

What to do in case of emergency/overdose?

Symptoms of overdosage may include:

• nausea, vomiting, headache, drowsiness, visual disturbances, cardiovascular collapse, convulsions, hypokalemia, rhythm and conduction disorders including QT prolongation, torsades de pointes, ventricular tachycardia and ventricular fibrillation, followed by sudden potentially fatal respiratory and cardiac arrest.
• Cases of extrapyramidal disorders have also been reported in the context of chloroquine overdose.

Management of overdosage:

• In case of overdose, call the poison control helpline of your country. In the United States, call 1-800-222-1222.

• Overdose related information is also available online at poisonhelp.org/help.
• In the event that the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services. In the United States, call 911.
• Treatment is symptomatic and must be prompt with immediate evacuation of the stomach by emesis or gastric lavage followed by treatment with activated charcoal.
• Chloroquine overdose is a life-threatening emergency and should be managed with cardio-respiratory and hemodynamic support, monitoring of potassium along with management of arrhythmias and convulsions, as necessary.
• A patient who survives the acute phase and is asymptomatic should be closely observed until all clinical features of toxicity resolve.

Can this medicine be used in pregnancy?

• Usage of chloroquine during pregnancy should be avoided except in the prophylaxis or treatment of malaria when the benefit outweighs the potential risk to the fetus.
• There are no adequate and well-controlled studies evaluating the safety and efficacy of chloroquine in pregnant women.

Can this medicine be used in children?

• In infants and children the dosage is preferably calculated by body weight.

What are the active and inactive ingredients in this medicine?

Active ingredient:

• chloroquine phosphate

Inactive ingredients:

• silicon dioxide
• anhydrous dibasic calcium phosphate
• hypromelloses
• magnesium stearate
• cellulose, microcrystalline
• polyethylene glycol
• polysorbate 80
• starch, corn
• sodium starch glycolate type a potato
• titanium dioxide

Who manufactures and distributes this medicine?

Manufactured by:

• Natco pharma limited
• Kothur,
• India.

Manufactured for:

• Rising Pharmaceuticals Inc.
• Saddle Brook, NJ

What should I know about storage and disposal of this medication?

• Dispense in tight, light-resistant container as defined in the USP/NF.
• Store at 25° C (77° F); excursions permitted to 15° – 30° C (59° – 86° F).

• Dailymed label info on Chloroquine
• FDA Chloroquine

Chloroquine Resources
Latest articles Most recent articles Ongoing trials	Wikipedia