A nurse is caring for a client who recently traveled to a malaria-stricken country. The client is diagnosed with malaria and is prescribed chloroquine (Aralen). Which of the following adverse effects should the nurse educate the client regarding this medication?

A) Retinal toxicity: Chloroquine (Aralen), an antimalarial medication, is known to cause retinal toxicity, especially when used for prolonged periods or at high doses. Retinal toxicity can lead to damage to the retina, resulting in visual disturbances, blurred vision, and potentially permanent vision loss. This is a well-known adverse effect of chloroquine, and it is particularly concerning with long-term use. Patients taking chloroquine should be monitored regularly for signs of retinal damage, and baseline and periodic eye exams are recommended to assess for any changes in vision. Educating the client about the potential risk of retinal toxicity is important so they can report any visual disturbances promptly. B) Nephrotoxicity: Nephrotoxicity (kidney damage) is not a common adverse effect of chloroquine. While chloroquine can be excreted through the kidneys, it does not typically cause direct nephrotoxicity. However, renal function should be monitored in patients with pre-existing kidney disease, as dose adjustments may be necessary in such cases. In general, nephrotoxicity is not a primary concern with chloroquine, unlike other medications that are more commonly associated with kidney damage. C) Hepatotoxicity: While some antimalarial medications, such as atovaquone-proguanil or mefloquine, may have hepatotoxic effects, hepatotoxicity is not a common or significant adverse effect of chloroquine. However, like any medication, chloroquine should be used with caution in patients with liver disease, as liver dysfunction may affect the drug's metabolism. Nonetheless, hepatotoxicity is not a primary adverse effect to focus on for chloroquine use in the treatment of malaria. D) Pancytopenia: Pancytopenia, which refers to a reduction in all three blood cell types (red blood cells, white blood cells, and platelets), is not a common or expected adverse effect of chloroquine. While some antimalarial drugs may cause hematologic issues, such as agranulocytosis or thrombocytopenia, chloroquine is more commonly associated with gastrointestinal symptoms, skin reactions, and ocular toxicity. Pancytopenia is a rare and more serious adverse effect typically linked with other drugs, such as certain chemotherapeutic agents or immunosuppressants, rather than chloroquine.