What is Chloroquine?
Chloroquine is an antimalarial drug. It is also used for other medical conditions. It is not exactly known how its mechanism of action works but it is suspected to inhibit certain enzymes from its interaction with DNA.
Chloroquine Clinical Indications
Chloroquine was originally made for the treatment of malaria. It is also used for the treatment of arthritis and lupus.
Chloroquine Systemic Side Effects
Chloroquine is stored in high concentrations in tissues all over the body. It is very slowly eliminated from these tissues. Chloroquine has many side effects and those include:
Nerve and muscle weakness
Change in hair color
Tinnitus or ringing in the ears
Loss of appetite
Chloroquine Ocular Side Effects
Chloroquine is especially absorbed by the pigment cells in the eye. Eye side effects are serious and can result in loss of vision. The side effects may occur at anytime. The higher the dose and the longer the time of use makes it more likely to occur. This is due to the fact that it accumulates in the pigment cells in the eye over time and dosage level.
Chloroquine accumulates in the retinal pigment cells resulting in damage to those cells. The common clinical finding is a bull’s eye appearance of the pigment cells in the macula (responsible for the central clear vision). This results in blurred vision, distorted vision, loss of color vision, and/or visual field defects. This loss of vision is permanent.
Monitoring Patients Taking Chloroquine
Since the vision lock is permanent, it is extremely important to diagnose any changes in the retina as early as possible. Regular dilated eye exams every 6 months are required. Also a visual field test will be performed to see if there are any changes present. Color vision may also be tested as a change in color vision can be an early indication of damage to the eye from Chloroquine. If any damage is detected, the drug must be discontinued immediately.
Chloroquine can cause a severe permanent loss of vision. It is important to monitor the status of the eye every 6 months and discontinue the Chloroquine immediately if any damage or change in vision is detected.