Aralen (chloroquine phosphate) is a 4-aminoquinoline compound for oral administration. It is used to prevent or treat malaria caused by mosquito bites.
This drug has an antiprotozoal action. It also has an immunosuppressive and anti-inflammatory effect. It causes the death of asexual erythrocyte forms of all types of plasmodia. It has a gametocidal effect, with the exception of Plasmodium falciparum (exhibits an anti-gametocidal effect).
The drug is used to treat:
- malaria (prevention and treatment of all types);
- extraintestinal amoebiasis;
- amoebic liver abscess;
- systemic lupus erythematosus (chronic and subacute forms);
- rheumatoid arthritis;
Dosage and administration
The pills are taken orally.
- Prevention of malaria – 0.5 g 2 times in the first week, then 1 time on the same day of the week;
- Treatment of malaria: 1 g on the 1 day, after 6-8 hours – 0.5 g, on the 2 and 3 days – 0.75 g daily in one dose;
- Amoebiasis: 0.5 g 3 times/day for 7 days, then 0.25 g 3 times/day for another 7 days, then 0.75 g 2 times a week for 2-6 months;
- Rheumatoid arthritis: 0.5 g 2 times/day for 7 days, then – 0.5 g every day for 12 months;
- Systemic lupus erythematosus: 0.25-0.5 g every day;
- Photodermatosis, 0.25 g every day for a week, then 0.5-0.75 g every week.
Do not use Aralen in the presence of any of the following conditions:
- liver failure;
- renal failure;
- inhibition of bone marrow hematopoiesis;
- severe rhythm disturbances;
- psoriatic arthritis;
With caution: glucose-6-phosphate dehydrogenase deficiency, retinopathy, epilepsy.
- Digestive system: nausea, vomiting, diarrhea;
- Central nervous system: dizziness, headache, sleep disturbances, psychoses, convulsive seizures;
- Eyes: With prolonged use – cloudy cornea, retinal lesions, and visual impairment;
- Dermatological reactions: discoloration of the skin and hair, dermatitis, photosensitivity;
- Hemopoietic system: thrombocytopenia, neutropenia, anemia, agranulocytosis;
- Cardiovascular system: rarely – myocardial damage with changes in the ECG, lowered blood pressure;
- Allergic reactions: skin rash, itching.
Chloroquine is rapidly and almost completely absorbed. Toxic doses can be lethal, especially for children (more than 1 g).
The main symptoms of an overdose develop in a few minutes: headache, nausea, vomiting, gastrointestinal disturbances, drowsiness, dizziness, hypokalemia, visual impairment, sudden loss of vision, arterial hypotension, arrhythmia, circulatory collapse due to cardiotoxic effect, cardiovascular failure, convulsions, heart and respiratory failure, respiratory arrest, coma, then death after a few hours.
Treatment. There is no specific antidote. Emergency treatment should be started with intensive and supportive care, including respiratory support, the administration of adrenaline and diazepam to prevent cardiotoxicity and arrhythmias (iv adrenaline infusion, starting from 0.25 μg / kg/min and increasing by 0.25 μg / kg/min until the corresponding systolic pressure is restored; diazepam should be administered as an infusion at a dose of 2 mg/kg for 30 minutes, then 1-2 mg/kg per day for 2-4 days). Gastric lavage may be also indicated.
If a little time has passed since the drug was used, activated charcoal can be taken to reduce further absorption (the dose should exceed the expected dose of chloroquine taken at least 5 times).
Dialysis and metabolic transfusions can be considered as possible additions to therapy.
- Co-administration of chloroquine with phenylbutazone, gold preparations, penicillamine, cytostatics, levamisole increases the likelihood of bone marrow aplasia and skin lesions;
- Antacids disrupt absorption, cimetidine increases the concentration of the drug in the blood;
- Combination of chloroquine and other antimalarial drugs may be accompanied by an antagonistic effect;
- Combination of chloroquine and GCS increases the risk of developing myopathy and cardiomyopathy;
- Combination of chloroquine and MAO inhibitors increases the risk of neurotoxicity;
- Combination of chloroquine and ethanol increases the risk of hepatotoxicity;
- Combination of chloroquine and cardiac glycosides increases the risk of glycosidic intoxication.
- Given the benefit/risk ratio, Aralen can be used to treat acute attacks of malaria caused by sensitive strains of plasmodia, even in cases of hypersensitivity to 4-aminoquinolines, epilepsy, gastrointestinal disorders, liver and kidney diseases;
- The drug can cause severe exacerbation of psoriasis and porphyria;
- Use the drug with caution if you have cirrhosis, porphyria, psoriasis, or if you are taking medications that affect the blood;
- There are a limited number of patients who reported diffuse parenchymal lung disease after taking chloroquine pills;
- A few patients experienced DRESS syndrome after using chloroquine pills;
- An ophthalmological examination is required before starting long-term treatment and every 3-6 months with continuous use for more than 12 months.
- If the daily dose exceeds 150 mg and is used for a long time, it is recommended to perform ophthalmological monitoring every 3-6 months. In cases of irreversible visual impairment, including retinopathy, use of the drug should be stopped immediately;
- Infection with quinoline resistant P. falciparum strains should be treated with other anti-malarial drugs (e.g. quinine);
- Children are especially sensitive to 4-aminoquinolines, so the drug should be stored out of reach of them. There are reports of lethal consequences of poisoning after the accidental use of even low doses (0.75 or 1 g). In such cases, an immediate gastric lavage is recommended;
- Since the active substance accumulates in the liver, the drug should be used with caution in patients with impaired liver function or in persons suffering from alcoholism;
- During prolonged use, it is necessary to check tendon reflexes and conduct a detailed blood test every 3-6 months;
- Treatment should be stopped immediately if muscle weakness occurs;
- With prolonged use, it is necessary to conduct a complete blood test every 3-6 months;
- The lengthening of the QTc interval and the potential lengthening of the QTc interval are associated with clinical conditions. An extension of the QTc interval has been reported in some patients who used this drug. Therefore, chloroquine should be used with caution in patients with existing proarrhythmogenic conditions, such as acute myocardial ischemia or lengthening of the QT interval since its use can lead to an increased risk of ventricular arrhythmias and cardiac arrest. The magnitude of elongation can increase with increasing concentration of the drug. Therefore, it is not recommended to exceed the recommended dosage;
- If you have symptoms of cardiac arrhythmia that occurred during treatment with chloroquine, treatment should be discontinued;
- During prolonged treatment, you should regularly visit a cardiologist due to the possibility of developing cardiomyopathy;
- Some patients taking chloroquine to treat cardiomyopathy reported cases of heart failure. If the signs and symptoms of cardiomyopathy appear during treatment with this drug, treatment should be discontinued;
- Since the safety of Aralen during pregnancy is not confirmed, it is used only in cases where possible fetal damage is less dangerous than malaria;
- Chloroquine passes into the mother’s breast milk. The amount of the substance is not sufficient for the chemoprophylaxis of infants. Therefore, it is necessary to stop breastfeeding if it is necessary to take this drug;
- Aralen may impair the ability to drive, operate machinery and perform the work that requires good vision, accuracy, coordination, and the ability to maintain balance.
Store at 25° C (77° F), away from direct sunlight, heat and moisture. Keep out of reach of children and pets. Do not the pills that have already expired.