Chlorochin - General Information
The prototypical antimalarial agent with a mechanism that is not well understood. It has also been used to treat rheumatoid arthritis, systemic lupus erythematosus, and in the systemic therapy of amebic liver abscesses.
Pharmacology of Chlorochin
Chlorochin is the prototype anti malarial drug, most widely used to treat all types of malaria except for disease caused by chloroquine resistant Plasmodium falciparum. It is highly effective against erythrocytic forms of Plasmodium vivax, Plasmodium ovale and Plasmodium malariae, sensitive strains of Plasmodium falciparum and gametocytes of Plasmodium vivax. Being alkaline, the drug reaches high concentration within the food vacuoles of the parasite and raises its pH. It is found to induce rapid clumping of the pigment. Chlorochin inhibits 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. It may also interfere with the biosynthesis of nucleic acids.
Chlorochin for patients
Complete blood cell counts should be made periodically if patients are given prolonged therapy. If any severe blood disorder appears which is not attributable to the disease under treatment, discontinuance of the drug should be considered. The drug should be administered with caution to patients having G-6-PD (glucose-6 phosphate dehydrogenase) deficiency.
In patients with preexisting auditory damage, chloroquine should be administered with caution. In case of any defects in hearing, chloroquine should be immediately discontinued, and the patient closely observed.
Since this drug is 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.
Patients with history of epilepsy should be advised about the risk of chloroquine provoking seizures.
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.
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.
Antacids and kaolin: Antacids and kaolin can reduce absorption of chloroquine; an interval of at least 4 hours between intake of these agents and chloroquine should be observed.
Cimetidine: Cimetidine can inhibit the metabolism of chloroquine, increasing its plasma level. Concomitant use of cimetidine should be avoided.
Ampicillin: In a study of healthy volunteers, chloroquine significantly reduced the bioavailability of ampicillin. An interval of at least two hours between intake of this agent and chloroquine should be observed.
Cyclosporin: After introduction of chloroquine (oral form), a sudden increase in serum cyclosporin level has been reported. Therefore, close monitoring of serum cyclosporin level is recommended and, if necessary, chloroquine should be discontinued.
Use of this drug is contraindicated in the presence of retinal or visual field changes either attributable to 4-aminoquinoline compounds or to any other etiology, and in patients with known hypersensitivity to 4-aminoquinoline compounds. However, in the treatment of acute attacks of malaria caused by susceptible strains of plasmodia, the physician may elect to use this drug after carefully weighing the possible benefits and risks to the patient.
Additional information about Chlorochin
Chlorochin Indication: For the suppressive treatment and for acute attacks of malaria due to P. vivax, P.malariae, P. ovale, and susceptible strains of P. falciparum, Second-line agent in treatment of Rheumatoid Arthritis
Mechanism Of Action: The mechanism of plasmodicidal action of chloroquine is not completely certain. Like other quinoline derivatives, it is thought to inhibit heme polymerase activity. This results in accumulation of free heme, which is toxic to the parasites.
Drug Interactions: Aluminium The antiacid decreases the absorption of chloroquine
Atomoxetine The CYP2D6 inhibitor could increase the effect and toxicity of atomoxetine
Bismuth The antiacid decreases the absorption of chloroquine
Calcium The antiacid decreases the absorption of chloroquine
Cyclosporine Increases the effect of cyclosporine
Dihydroxyaluminium The antiacid decreases the absorption of chloroquine
Magnesium oxide The antiacid decreases the absorption of chloroquine
Magnesium The antiacid decreases the absorption of chloroquine
Mesoridazine Increased risk of cardiotoxicity and arrhythmias
Praziquantel Markedly lower praziquantel levels
Thioridazine Increased risk of cardiotoxicity and arrhythmias
Attapulgite The antiacid decreases the absorption of chloroquine
Kaolin The antiacid decreases the absorption of chloroquine
Food Interactions: Take with food to reduce irritation and increase bioavailability.
Generic Name: Chloroquine
Synonyms: Chloroquine Phosphate; Chloroquina; Chlorochine; Chloroquinium; Chloraquine; Chlorquin; Clorochina; Hydroxychloroquine Sulfate
Drug Category: Antirheumatic Agents; Antimalarials; Amebicides
Drug Type: Small Molecule; Approved
Absorption: Completely absorbed from gastrointestinal tract
Toxicity (Overdose): Not Available
Protein Binding: ~55% of the drug in the plasma is bound to nondiffusible plasma constituents
Biotransformation: Hepatic (partially)
Half Life: 1-2 months
Dosage Forms of Chlorochin: Tablet Oral
Chemical IUPAC Name: N'-(7-chloroquinolin-4-yl)-N,N-diethylpentane-1,4-diamine
Chemical Formula: C18H26ClN3
Chloroquine on Wikipedia: https://en.wikipedia.org/wiki/Chloroquine
Organisms Affected: Plasmodium