Front line physicians treating patients with SARS-CoV2/COVID-19 are seeing an unprecedented, alarming, and escalating orchestrated attack on chloroquine (CQ) and its safer derivative, hydroxychloroquine (HCQ). Both medicines have been safely used in millions of patients worldwide for malaria prevention and treatment since they were FDA approved for safety and effectiveness in 1934 and 1955, respectively. The World Health Organization (WHO) lists CQ and HCQ as “essential medicines” because of safety, effectiveness, low cost, and wide availability. 
The United States CDC itself has published guidelines on its website: “Who can take hydroxychloroquine (Placquenil)? Hydroxychloroquine can be prescribed to adults and children of all ages. It can also be safely taken by pregnant women and nursing mothers.”
The CDC Guidelines address side effects: Hydroxychloroquine is a relatively well tolerated medicine. The most common adverse reactions reported are stomach pain, nausea, vomiting, and headache. These side effects can often be lessened by taking hydroxychloroquine with food. Hydroxychloroquine may also cause itching in some people. All medicines may have some side effects. Minor side effects such as nausea, occasional vomiting, or diarrhea usually do not require stopping the antimalarial drug.”
CDC addresses duration of use: “How long is it safe to use hydroxychloroquine? CDC has no limits on the use of hydroxychloroquine for the prevention of malaria. When hydroxychloroquine is used at higher doses for many years, a rare eye condition called retinopathy has occurred. People who take hydroxychloroquine for more than five years should get regular eye exams. 
NOTICE: The CDC guidelines for use in malaria do not even mention the “fatal heart arrhythmia” hyped in the fear-mongering articles in the media recently. Rheumatology guidelines for using HCQ for Lupus and Rheumatoid Arthritis (RA) patients do not require a baseline EKG to check heart rhythm, though doctors might order one before using these medicines if needed for a patient with heart disease.
So our own CDC has said CQ and HCQ are safe and well tolerated for potentially long periods of time preventing and treating malaria. FDA later approved HCQ for treating Lupus and RA, with millions taking much higher doses over decades, not days.