Chloroquine
Chloroquine is a generic medication for the drug Aralen:
Chloroquine medication comes in several different strengths; click on the strength you need to view prices from pharmacies competing to earn your business.
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Chloroquine 250 mg
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Chloroquine 500 mg
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Drug Interactions
See Table 1.
Dosage and Administration
Chlroroquine
Dose in Pediatric Patients
| Indication | Initial Dose | Usual Dose | Maximum Dose | Duration of Treatment | Detailed Information |
|---|---|---|---|---|---|
| Malaria Prophylaxis | 8.3 mg/kg (5 mg/kg base) weekly | 8.3 mg/kg (5 mg/kg base) weekly | Do not exceed adult dose | 1–2 weeks prior to exposure and continued for 4 weeks after leaving the endemic area | Give 16.7 mg/kg (10 mg/kg base) in 2 divided doses 6 hours apart prior to initiating usual dose if chloroquine is not initiated 2 weeks prior to exposure. |
| Malaria Treatment | 16.7 mg/kg (10 mg/kg base) | 8.3 mg/kg (5 mg/kg base) | Do not exceed adult dose | 2 days | 16.7 mg/kg (10 mg/kg base) initially followed by 8.3 mg/kg (5 mg/kg base) given 6, 24 and 48 hours after. |
| Extraintestinal Amebiasis | 16.7 mg/kg (10 mg/kg base) daily | 16.7 mg/kg (10 mg/kg base) daily | Do not exceed adult dose | 2–3 weeks | Administer in conjuction with an intestinal amebicide. |
Administration
Missed Dose
If chloroquine is taken weekly, the missed dose should be taken as soon as the patient remembers. Wait 7 days before taking the next dose. If chloroquine is taken daily, the missed dose should be take as soon as the patient remembers. If it is almost time for the next dose, the missed dose should not be taken and the patient should return to the regular dosage schedule.
Hepatic Impairment
Since chloroquine may concentrate in the liver, it should be used with caution in patients with hepatic disease.
Chloroquine
Dose in Adult Patients
| Indication | Initial Dose | Usual Dose | Duration of Treatment | Detailed Information |
|---|---|---|---|---|
| Malaria Prophylaxis | 500 mg (300 mg base) weekly | 500 mg (300 mg base) weekly | 1–2 weeks prior to exposure and continued for 4 weeks after leaving the endemic area | Use a loading dose of 1000 mg if chloroquine is not initiated 2 weeks prior to exposure. |
| Malaria Treatment | 1000 mg followed by 500 mg after 6–8 hours (day 1) | 500 mg daily (day 2 and 3) | 3 days | 1000 mg followed by an additional 500 mg dose given 6, 24 and 48 hours after. |
| Extraintestinal Amebiasis | 1000 mg daily for 2 days | 500 mg daily | 2–3 weeks | Administer in conjunction with an intestinal amebicide. |
| Rheumatoid Arthritis | 250 mg daily | 250 mg daily | Use the lowest effective dose. A response to chloroquine therapy may not occur for 4–6 weeks. | |
| Lupus Erythematosus | 250 mg daily | 250 mg daily | Use in conjunction with topical steroids. When systemic and local manifestations subside, gradually taper chloroquine and discontinue. |
Chloroquine
Dose in Adult Patients with Renal Impairment
| Indication | Route | Creatinine Clearance | Dose Adjustment |
|---|---|---|---|
| Malaria Treatment | Oral | >10 mL/min | no adjustment |
| <10 mL/min | decrease dose by 50% |
Oral
Chloroquine can be given with food to minimize GI adverse effects. Take at the same time and day every week. Tablets may be crushed and mixed with a flavoured vehicle.
Adverse Reactions
Gastrointestinal
anorexia, vomiting.
Hematologic
blood dyscrasias.
Less Common Adverse Drug Reactions
Chloroquine
Common Adverse Drug Reactions
| Body System | Incidence |
|---|---|
| Gastrointestinal | |
| Nausea | >1% |
| Diarrhea | >1% |
Miscellaneous
fatigue, personality changes, hair bleaching, stomatitis.
Ophthalmologic
blurred vision, retinopathy.
Cardiovascular
EKG changes, hypotension.
Supplied
Not currently available for CPhA monographs. Please consult individual product monographs.
Indications and Clinical Use
Pediatrics
Chloroquine has been used in children to treat and prevent malaria and to treat extraintestinal amebiasis.
Warnings and Precautions
Hepatic/Biliary/Pancreatic
Since chloroquine may concentrate in the liver, it should be used with caution in conjunction with other hepatotoxic drugs or in patients with hepatic disease or alcoholism
Special Populations
Hematologic
A complete blood count should be checked periodically while on long-term chloroquine therapy. If any adverse hematologic effects are detected, chloroquine should be discontinued. Chloroquine should be used with caution in patients with glucose-6-phosphate dehydrogenase (G-6-PD) deficiency since hemolysis and acute renal failure have occurred in these patients receiving chloroquine.
General
Patients on long-term chloroquine therapy should be examined periodically for muscle weakness (including knee and ankle reflex tests). If there is evidence of muscle weakness, chloroquine should be discontinued. Chloroquine may exacerbate porphyria in patients with the condition.
Skin
Chloroquine may exacerbate psoriasis in patients with the disease.
Ophthalmologic
Dose-related, irreversible retinal damage has been associated with long-term or high-dose chloroquine therapy. If chloroquine is to be used long term, ophthalmologic examinations (including visual acuity, expert slit lamp, funduscopic and visual field tests) should be performed at baseline and periodically during therapy. If there are any abnormalities, discontinue chloroquine immediately and observe the patient for possible progression.
Pregnant Women
Birth defects have not been associated with the use of chloroquine in pregnancy. Therapeutic use is not known to convey a significant risk of ocular toxicity to the infant. Chloroquine should only be used in pregnancy when the benefit outweighs the risk.
Pediatrics
Since chloroquine overdoses are often fatal, extreme care should be taken when administrating doses to children. Chloroquine should be kept out of reach of children.
Nursing Women
Chloroquine is excreted in breast milk, however the amount is not considered to be harmful to a nursing infant. The American Academy of Pediatrics considers chloroquine to be compatible with breastfeeding. Chloroquine should be used with caution in infants with G-6-PD deficiency.
Contraindications
Patients who are hypersensitive to chloroquine or to other 4-aminoquinoline compounds or to any ingredient in the formulation or component of the container. Retinal or visual field changes attributable to 4-aminoquinoline compounds or to any other etiology. Chloroquine may be used in these patients for the treatment of acute attacks of malaria caused by susceptible strains of plasmodia if the benefits outweigh the risks.
Action and Clinical Pharmacology
Distribution
Chloroquine is extensively distributed into body tissues (i.e., eyes, heart, kidneys, liver, lungs) with an apparent volume of distribution of 116-285 L/kg. Chloroquine is moderately bound to protein (50-65%).
Absorption
Chloroquine tablets are absorbed rapidly and almost completely with a bioavailability of 89%. The time to peak concentration is 1-2 hours.
Excretion
70% of chloroquine is excreted unchanged in the urine.
Chloroquine
Summary of Pharmacokinetic Parameters in Adults
| t1/2 (h) | Clearance | Volume of Distribution | |
|---|---|---|---|
| Single Dose Mean | 72–120 | 0.35 L/kg/h | 116–285 L/kg |
Metabolism
Chloroquine is partially metabolized by the liver. The major metabolite is desethylchloroquine which is active. Chloroquine inhibits CYP2D6.
Overdose
Recommended Management
It is recommended that a Poison Control Centre be contacted to obtain expert advice on the management of chloroquine overdose.
Early and aggressive management of chloroquine overdose substantially reduces mortality rates. Closely observe ECG, serum potassium, arterial blood gases and vital signs, especially for hypotension. For hypotension unresponsive to iv fluids, epinephrine iv infusion should be started at a dose of 0.25 µg/kg/min and titrated until a systolic blood pressure over 100 mm Hg is achieved. Diazepam, 2 mg/kg iv infused over 30 minutes, may be used to decrease the cardiotoxicity of chloroquine and to control seizures. A single dose of activated charcoal should be considered at a dose of 1 g/kg for patients who present within 2 hours of ingestion. Chloroquine is not removed by hemodialysis, peritoneal dialysis or charcoal hemoperfusion.
Signs and Symptoms
Chloroquine overdose is extremely toxic and symptoms often develop within minutes. Apnea, hypotension, respiratory and cardiovascular compromise can be precipitous. CNS involvement includes decreased level of consciousness, seizures and coma.
