Aralen has anti-inflammatory activity and is sometimes prescribed in high doses to treat the autoimmune diseases rheumatoid arthritis, systemic lupus erythematosus, and discoid lupus erythematosus. In these diseases, the body's immune system is overactive and causes inflammation that results in the disease symptoms.
Aralen is active against other types of protozoa, including one called Entamoeba histolytica. Metronidazole is the drug of choice for infections with this parasite, but chloroquine can be prescribed to treat liver infections if metronidazole is not available.
Aralen is prescribed both to prevent and to treat malaria. For prevention it is usually taken in combination with another antimalarial drug called proguanil. However, the malaria parasite is resistant to these drugs in certain areas of the world, and it is important to check with your pharmacist which drugs are currently recommended to prevent malaria in the country you are travelling to. You can check in the travel section of this site.
Aralen suppresses the inflammation and the disease process.
Aralen tablets contain the active ingredient chloroquine phosphate, which is an antimalarial drug, though it has other uses, for example, in treating the autoimmune diseases rheumatoid arthritis and lupus erythematosus.
Aralen works by attacking the parasites once they have entered the red blood cells. Aralen kills the parasites and prevents them from multiplying further.
Higher doses than those prescribed for preventing malaria are prescribed to treat malaria infection. Chloroquine may be given by injection to treat malaria, if administration by mouth is not possible. However, chloroquine is no longer recommended for treating falciparum malaria, because there is widespread resistance of the Plasmodium falciparum parasite to chloroquine.
If chloroquine is recommended for prevention it should be started a week before travel to the malarious region. It should then be taken throughout the stay, so that if you are bitten by an infected mosquito, there will be drug in your blood to prevent malaria developing. Chloroquine should be continued for a further four weeks after leaving the malarious area, so that there is still drug in the blood to kill any remaining parasites released from the liver into the red blood cells during this time.
In rheumatoid arthritis, chloroquine is known as a disease-modifying antirheumatic drug. It doesn't have an immediate effect, but requires four to six months of treatment for a full response. If there is no real benefit on the disease after taking Aralen for six months, your doctor will usually ask you to stop taking it and try a different DMARD.
It is not fully understood how chloroquine kills the parasites, but it is thought to work by blocking the action of a chemical that the parasites produce to protect themselves once inside the red blood cells. When inside the red blood cells, the malaria parasites digest the oxygen carrying pigment haemoglobin that is found in these cells. This divides the haemoglobin into two parts haem and globin, and the haem part is toxic to the malaria parasite. To prevent itself from being damaged by haem, the malaria parasite produces a chemical that converts haem into a compound that is not toxic to them. Chloroquine blocks the action of this chemical. This causes the levels of the toxic haem to rise, thus killing the malaria parasites.
Malaria is a potentially fatal disease caused by various types of single-celled parasites known as Plasmodium.
Once in the blood, the parasites travel to the liver, where they multiply.
Plasmodium are carried by mosquitoes and injected into the bloodstream during a bite from an infected mosquito.
The attacks do not begin until a sufficient number of blood cells have been infected with parasites.
The parasites are then released back into the bloodstream where they invade the red blood cells and multiply again. An actual attack of malaria develops when the red blood cells burst, releasing a mass of parasites into the bloodstream.
Aralen is prescribed for:
- Infection of the liver with entamoeba histolytica;
- Inflammatory disease of the joints;
- Prevention of malaria;
- Systemic lupus erythematosus and discoid lupus erythematosus;
- Treatment of malaria;
Aralen side effects that you should report to your health care professional or doctor as soon as possible:
- Weakening of the heart muscle;
- Weakening of muscles;
- Visual disturbances;
- Skin rashes;
- Low blood pressure, this might make you feel dizzy;
- Loss of hair colour;
- Liver disorders;
- Hearing distubances, eg ringing in the ears or hearing loss;
- Hair loss;
- Disturbances of the gut such as diarrhoea, nausea, vomiting or abdominal pain;
- Disturbance in the normal numbers of blood cells in the blood;
- Discolouration of skin, nails, or mucous membranes, eg inside of mouth;
- Damage to the retina of the eye;
- Changes in the electrical signals in the heart;
- Anxiety, confusion, hallucinations or strange or abnormal thoughts;