It has been found that certain strains of P. falciparum have become resistant to 4-aminoquinoline compounds (including chloroquine and hydroxychloroquine). Chloroquine resistance is widespread and, at present, is particularly prominent in various parts of the world including sub-Saharan Africa, Southeast Asia, the Indian subcontinent, and over large portions of South America, including the Amazon basin1.
Before using chloroquine for prophylaxis, it should be ascertained whether chloroquine is appropriate for use in the region to be visited by the traveler. Chloroquine should not be used for treatment of P. falciparum infections acquired in areas of chloroquine resistance or malaria occurring in patients where chloroquine prophylaxis has failed.
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.
Irreversible retinal damage has been observed in some patients who had received long-term or high-dosage 4-aminoquinoline therapy. Retinopathy has been reported to be dose related.
When prolonged therapy with any antimalarial compound is contemplated, initial (base line) and periodic ophthalmologic examinations (including visual acuity, expert slit-lamp, funduscopic, and visual field tests) should be performed.
If there is any indication (past or present) of abnormality in the visual acuity, visual field, or retinal macular areas (such as pigmentary changes, loss of foveal reflex), or any visual symptoms (such as light flashes and streaks) which are not fully explainable by difficulties of accommodation or corneal opacities, the drug should be discontinued immediately and the patient closely observed for possible progression. Retinal changes (and visual disturbances) may progress even after cessation of therapy.
All patients on long-term therapy with this preparation 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.
A number of fatalities have been reported following the accidental ingestion of chloroquine, sometimes in relatively small doses (0.75 g or 1 g chloroquine phosphate in one 3-year-old child). Patients should be strongly warned to keep this drug out of the reach of children because they are especially sensitive to the 4-aminoquinoline compounds.
Use of chloroquine phosphate in patients with psoriasis may precipitate a severe attack of psoriasis. When used in patients with porphyria the condition may be exacerbated. The drug should not be used in these conditions unless in the judgment of the physician the benefit to the patient outweighs the potential risks.
Usage in Pregnancy:
Radioactively tagged chloroquine administered intravenously to pregnant pigmented CBA mice passed rapidly across the placenta and accumulated selectively in the melanin structures of the fetal eyes. It was retained in the ocular tissues for five months after the drug had been eliminated from the rest of the body2. There are no adequate and well-controlled studies evaluating the safety and efficacy of chloroquine in pregnant women. Usage of chloroquine during pregnancy should be avoided except in the suppression or treatment of malaria when in the judgment of the physician the benefit outweighs the potential risk to the fetus.
Chloroquine phosphate is indicated for the suppressive treatment and for acute attacks of malaria due to P. vivax, P. malariae, P. ovale, and susceptible strains of P. falciparum. The drug is also indicated for the treatment of extraintestinal amebiasis.
Chloroquine phosphate does not prevent relapses in patients with vivax or malariae malaria because it is not effective against exoerythrocytic forms of the parasite, nor will it prevent vivax or malariae infection when administered as a prophylactic. It is highly effective as a suppressive agent in patients with vivax or malariae malaria, in terminating acute attacks, and significantly lengthening the interval between treatment and relapse. In patients with falciparum malaria it abolishes the acute attack and effects complete cure of the infection, unless due to a resistant strain of P. falciparum.
Chloroquine phosphate tablets 250 mg, chloroquine phosphate, USP, is a 4-aminoquinoline compound for oral administration. It is a white, odorless, bitter tasting, crystalline substance, freely soluble in water.
Chloroquine phosphate is an antimalarial and amebicidal drug.
Chemically, it is 7-chloro-4-[[4- (diethylamino)-1-methylbutyl]amino] quinoline phosphate (1:2) and has the following structural formula:
Each tablet contains 250 mg of chloroquine phosphate USP, equivalent to 150 mg chloroquine base.
Chloroquine Phosphate | Rising Pharmaceuticals, Inc.
The dosage of chloroquine phosphate is often expressed in terms of equivalent chloroquine base. Each 250 mg tablet of chloroquine phosphate contains the equivalent of 150 mg chloroquine base. In infants and children the dosage is preferably calculated by body weight.
Malaria: Suppression - Adult Dose: 500 mg (= 300 mg base) on exactly the same day of each week.
Pediatric Dose: The weekly suppressive dosage is 5 mg calculated as base, per kg of body weight, but should not 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.
For Treatment of Acute Attack
Adults: An initial dose of 1 g (= 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.
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.
For radical cure of vivax and malariae malaria concomitant therapy with an 8-aminoquinoline compound is necessary.
Extraintestinal Amebiasis: Adults, 1 g (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.
Chloroquine Phosphate | Rising Pharmaceuticals, Inc.
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.
Malaria Suppression – Adult Dose: 500 mg (= 300 mg base) on exactly the same day of each week.
Pediatric Dose: The weekly suppressive dosage is 5 mg calculated as base, per kg of body weight, but should not 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.
For Treatment of Acute Attack
Adults: An initial dose of 1 g (= 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.
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.
For radical cure of vivax and malariae malaria concomitant therapy with an 8-aminoquinoline compound is necessary.
Extraintestinal Amebiasis Adults, 1 g (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.
Global Pharmaceuticals, Division Of Impax Laboratories, Inc.
Chloroquine Phosphate | Global Pharmaceuticals, Division Of Impax Laboratories, Inc.
The dosage of chloroquine phosphate is often expressed in terms of equivalent chloroquine base. Each 250 mg tablet of chloroquine phosphate contains the equivalent of 150 mg chloroquine base. In infants and children the dosage is preferably calculated on the body weight.
Malaria
Suppression-Adult Dose: 500 mg (= 300 mg base) on exactly the same day of each week.
Pediatric Dose: The weekly suppressive dosage is 5 mg calculated as base, per kg of body weight, but should not 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.
For treatment of acute attack, adults
An initial dose of 1 g (= 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.
The dosage for adults may also be calculated on the basis of body weight; this method is preferred for infants and children. A total dose representing 25 mg of base per kg of body weight is administered in three days, as follows:
First dose: 10 mg base per kg (but not exceeding a single dose of 600 mg base).
Second dose: 5 mg base per kg (but not exceeding a single dose of 300 mg base) 6 hours after first dose.
Third dose: 5 mg base per kg 18 hours after second dose.
Fourth dose: 5 mg base per kg 24 hours after third dose.
For radical cure of vivax and malariae malaria concomitant therapy with an 8-aminoquinoline compound is necessary.
Extraintestinal Amebiasis
Adults, 1 g (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.
Global Pharmaceuticals, Division Of Impax Laboratories, Inc.
Chloroquine Phosphate | Global Pharmaceuticals, Division Of Impax Laboratories, Inc.
The dosage of chloroquine 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.
Malaria: Suppression-Adult Dose: 500 mg (= 300 mg base) on exactly the same day of each week.
Pediatric Dose: The weekly suppressive dosage is 5 mg calculated as base, per kg of body weight, but should not 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.
For Treatment of Acute Attack.
Adults: An initial dose of 1 g (= 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.
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
For radical cure of vivax and malariae malaria concomitant therapy with an 8-amino-quinoline compound is necessary.
Extraintestinal Amebiasis: Adults, 1 g (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.
The dosage of chloroquine phosphate is often expressed in terms of equivalent chloroquine base. Each 500 mg tablet of chloroquine phosphate tablets, USP contains the equivalent of 300 mg chloroquine base. In infants and children the dosage is preferably calculated by body weight.
Malaria: Suppression—Adult Dose: 500 mg (= 300 mg base) on exactly the same day of each week.
Pediatric Dose: The weekly suppressive dosage is 5 mg calculated as base, per kg of body weight, but should not 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.
For Treatment of Acute Attack
Adults: An initial dose of 1 g (= 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.
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.
For radical cure of vivax and malariae malaria concomitant therapy with an 8-aminoquinoline compound is necessary.
Extraintestinal Amebiasis: Adults, 1 g (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.
Chloroquine Phosphate | Pd-rx Pharmaceuticals, Inc.
The dosage of chloroquine phosphate is often expressed in terms of equivalent chloroquine base. Each 500 mg tablet of chloroquine phosphate tablets, USP contains the equivalent of 300 mg chloroquine base. In infants and children the dosage is preferably calculated by body weight.
Malaria: Suppression—Adult Dose: 500 mg (= 300 mg base) on exactly the same day of each week.
Pediatric Dose: The weekly suppressive dosage is 5 mg calculated as base, per kg of body weight, but should not 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.
For Treatment of Acute Attack
Adults: An initial dose of 1 g (= 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.
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.
For radical cure of vivax and malariae malaria concomitant therapy with an 8-aminoquinoline compound is necessary.
Extraintestinal Amebiasis: Adults, 1 g (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.
Chloroquine Phosphate | Ranbaxy Pharmaceuticals Inc.
The dosage of chloroquine phosphate is often expressed in terms of equivalent chloroquine base. Each 500 mg tablet of chloroquine phosphate tablets contains the equivalent of 300 mg chloroquine base. In infants and children the dosage is preferably calculated by body weight.
Malaria: Suppression—Adult Dose: 500 mg (= 300 mg base) on exactly the same day of each week.
Pediatric Dose: The weekly suppressive dosage is 5 mg calculated as base, per kg of body weight, but should not 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.
For Treatment of Acute Attack
Adults: An initial dose of 1 g (= 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.
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.
For radical cure of vivax and malariae malaria concomitant therapy with an 8-aminoquinoline compound is necessary.
Extraintestinal Amebiasis: Adults, 1 g (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.
Chloroquine Phosphate | Ranbaxy Pharmaceuticals Inc.
The dosage of chloroquine phosphate is often expressed or calculated as the base. Each 250 mg tablet of chloroquine phosphate is equivalent to 150 mg base. In infants and children the dosage is preferably calculated on the body weight.
Malaria: Suppression— Adult Dose: 500 mg (= 300 mg base) on exactly the same day of each week.
Pediatric Dose: The weekly suppressive dosage is 5 mg calculated as base, per kg of body weight, but should not 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.
For Treatment of Acute Attack:
Adults: An initial dose of 1 g (= 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.
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.
For radical cure of vivax and malariae malaria concomitant therapy with an 8-aminoquinoline compound is necessary.
Extraintestinal Amebiasis: Adults:1 g (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.
The dosage of chloroquine phosphate is often expressed or calculated as the base. Each 250 mg tablet of chloroquine phosphate is equivalent to 150 mg base. In infants and children the dosage is preferably calculated on the body weight.
Malaria: Suppression— Adult Dose: 500 mg (= 300 mg base) on exactly the same day of each week.
Pediatric Dose: The weekly suppressive dosage is 5 mg calculated as base, per kg of body weight, but should not 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.
For Treatment of Acute Attack:
Adults: An initial dose of 1 g (= 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.
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.
For radical cure of vivax and malariae malaria concomitant therapy with an 8-aminoquinoline compound is necessary.
Extraintestinal Amebiasis: Adults:1 g (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.