The U.S. Food and Drug Administration on Monday approved the first injectable medication to lower the risk of contracting HIV, or the human immunodeficiency virus. HIV attacks the body’s immune system and causes AIDS (acquired immunodeficiency syndrome) if not treated. The FDA-approved medication is an injectable form of GlaxoSmithKline Plc’s cabotegravir drug. The injection, called Apretude (cabotegravir extended-release injectable suspension), is given every two months as a preventative treatment, or pre-exposure prophylaxis (PrEP), to reduce the risk of sexually-acquired HIV. After an initial injection, the drug is administered one month later, and then every two months thereafter. The FDA’s approval means the injection can be administered to at-risk adults and adolescents weighing at least 35 kilograms (77 pounds). The FDA said that patients can start their treatment with Apretude or with the oral cabotegravir for four weeks to see how well they tolerate the drug. The injection includes a boxed warning—the FDA’s strictest warning—to not use the …