Clinical medicine profile
Chloroquine phosphate
Antimalarial
- Route
- ORAL / PARENTERAL (severe malaria)
- Schedule
- POM
- ATC
- Not assigned
- PPB status
- registered
Safety essentials
The information most likely to change a prescribing or dispensing decision.
Contraindications
- CONTRAINDICATIONS Use of chloroquine phosphate tablets for indications other than acute malaria is contraindicated in the presence of retinal or visual field changes of any etiology.
- Use of chloroquine phosphate tablets is contraindicated in patients with known hypersensitivity to 4-aminoquinoline compounds.
Precautions
- WARNINGS Chloroquine-Resistant Malaria Chloroquine phosphate tablets are not effective against chloroquine-or hydroxychloroquine-resistant strains of Plasmodium species (see CLINICAL PHARMACOLOGY , Microbiology ).
- Chloroquine resistance is widespread in P. falciparum and is reported in P. vivax .
- Before using chloroquine for prophylaxis, it should be ascertained whether chloroquine is appropriate for use in the region to be visited by the traveler.
- Information regarding the geographic areas where resistance to chloroquine occurs, is available at the Centers for Disease Control and Prevention (www.cdc.gov\malaria).
- Patients infected with a resistant strain of plasmodia as shown by the fact that normally adequate doses have failed to prevent or cure clinical malaria or parasitemia should be treated with another form of antimalarial therapy.
- Treatment of Exo-Erythocytic Forms of Malaria 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 .
- Cardiac Effects including Cardiomyopathy and QT prolongation Fatal and life-threatening cardiotoxicity, including cardiomyopathy and arrhythmias, have been reported with the use of chloroquine (see ADVERSE REACTIONS and OVERDOSAGE ).
- In multiple cases, endomyocardial biopsy showed association of the cardiomyopathy with phospholipidosis in the absence of inflammation, infiltration or necrosis.
- Patients may present with ventricular hypertrophy and conduction disorders.
- ECG findings include atrioventircular, right or left bundle branch block.
- Chronic toxicity should be considered when conduction disorders (bundle branch block/ atrio-ventricular heart block) are diagnosed.
Dosing matrix
Population and organ-function guidance, shown together for faster comparison.
DOSAGE AND ADMINISTRATION The dosage of chloroquine phosphate is often expressed in terms of equivalent chloroquine base. 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. 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. If circumstances permit, suppressive therapy should begin two weeks prior to exposure. However, failing this in adults, an initial double (loading) dose of 1 g (= 600 mg base), or in children 10 mg base/kg may be taken in two divided doses, six hours apart. The suppressive therapy should be continued for eight weeks after leaving the endemic area. 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. The dosage for adults of low body weight and for infants and children should be determined as follows: First dose: 10 mg base per kg (but not exceeding a single dose of 600 mg base). Second dose: (6 hours after first dose) 5 mg base per kg (but not exceeding a single dose of 300 mg base). Third dose: (24 hours after first dose) 5 mg base per kg. Fourth dose: (36 hours after first dose) 5 mg base per kg. 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. 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. Geriatric Use See PRECAUTION S, Geriatric Use.
See label paediatric section if present; otherwise use paediatric formulary — do not extrapolate adult doses.
Supportive care critical in severe malaria; adjust supportive drugs as needed.
- CrCl 0–120: Confirm renal dosing in product SmPC / primary label.
Monitor if pre-existing liver disease; many agents hepatically metabolised.
Use, effects & interactions
Indications
- INDICATIONS AND USAGE Chloroquine phosphate tablets are 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 phosphate tablets do not prevent relapses in patients with vivax or ovale malaria because it is not effective against exoerythrocytic forms of the parasites.
- 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 (see WARNINGS ).
- Concomitant therapy with an 8-aminoquinoline drug is necessary for treatment of the hypnozoite liver stage forms of P.vivax and P.ovale (see DOSAGE AND ADMINISTRATION ).
Adverse effects
- ADVERSE REACTIONS The following adverse reactions have been identified during post-approval use of chloroquine or other 4-aminoqunoline compounds.
- Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.
- Ocular disorders: Maculopathy and macular degeneration have been reported and may be irreversible.
- Irreversible retinopathy with retinal pigmentation changes (bull’s eye appearance) and visual field defects (paracentral scotomas) in patients receiving long-term or high-dosage 4-aminoquinoline therapy have been reported (see WARNINGS ).
- Visual disturbances (blurring of vision and difficulty of focusing or accommodation)
- nyctalopia
- scotomatous vision with field defects of paracentral, pericentral ring types, and typically temporal scotomas (e.g., difficulty in reading with words tending to disappear, seeing half an object, misty vision, and fog before the eyes) have been reported.
- Reversible corneal opacities have also been reported.
- Immune system disorders: Urticaria, anaphylactic reaction including angioedema.
- Ear and labyrinth disorders: Nerve type deafness
- tinnitus, reduced hearing in patients with preexisting auditory damage.
- Musculoskeletal and connective tissue-disorders : Sensorimotor disorders, skeletal muscle myopathy or neuromyopathy leading to progressive weakness and atrophy of proximal muscle groups, depression of tendon reflexes and abnormal nerve conduction.
- Gastrointestinal disorders: Hepatitis, increased liver enzymes, anorexia, nausea, vomiting, diarrhea, abdominal cramps.
- Skin and subcutaneous tissue disorders: Erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis, exfoliative dermatitis.
Drug interactions
Open multi-drug checker ↗- Kenya: follow current MoH malaria guidelines for uncomplicated vs severe disease.
- Test before treat when feasible.
- Complete full ACT course.
- Severe malaria is an emergency — parenteral artesunate, not oral therapy alone.
Mechanism & disposition
Mechanism of Action: Chloroquine, a 4-aminoquinoline, is an anti-protozoal agent.
Read complete mechanism
Mechanism of Action: Chloroquine, a 4-aminoquinoline, is an anti-protozoal agent. The precise mechanism by which chloroquine exhibits activity is not known. Chloroquine, may exert its effect against Plasmodium species by concentrating in the acid vesicles of the parasite and by inhibiting polymerization of heme. It can also inhibit certain enzymes by its interaction with DNA. Activity in Vitro and in Clinical Infections: 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. In vitro studies with Chloroquine demonstrated that it is active against the trophozoites of Entamoeba histolytica. Drug Resistance: Resistance of Plasmodium parasites to chloroquine is widespread (see INDICATIONS AND USAGE , Limitations of Use in Malaria and WARNINGS ). Plasmodium parasites exhibiting reduced susceptibility to hydroxychloroquine also show reduced susceptibility to chloroquine. Patients in whom chloroquine or hydroxychloroquine have failed to prevent or cure clinical malaria or parasitemia, or patients who acquired malaria in a geographic area where chloroquine resistance is known to occur should be treated with another form of antimalarial therapy (see WARNINGS and INDICATIONS AND USAGE , Limitations of Use).
Hours (artemisinins rapid parasite clearance)
Regimen-dependent (ACT 3 days typical)
ORAL / PARENTERAL (severe malaria)
of chloroquine is quite slow,but is increased by acidification of the urine. Chloroquine is deposited in the tissues in considerable amounts. In animals, from 200 to 700 times the plasma concentration may be found in the liver,spleen, kidney, and lung; leukocytes also concentrate...
Pregnancy, lactation & diet
Treat malaria — untreated infection risks mother and fetus. Use trimester-appropriate regimens per Kenya MoH / WHO.
Most first-line ACTs compatible; continue breastfeeding with maternal treatment.
Brands & loaded prices
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Sources & review state
Decision support only. Confirm patient-specific decisions against the current product SmPC, Kenya STG/EML, and professional judgement.