Patient Rights Treatment Decisions & Safety Active Ingredient in a Medication Function By Michael Bihari, MD Michael Bihari, MD, is a board-certified pediatrician, health educator, and medical writer, and president emeritus of the Community Health Center of Cape Cod. Learn about our editorial process Michael Bihari, MD Updated on January 04, 2020 Print An active ingredient is the component of a medication responsible for the medication’s effects. In addition to therapeutic benefit, an active ingredient can also cause adverse or unintended effects which can result in patient discomfort or worse. When prescribing most medications, the beneficial effects of the medication should outweigh any adverse effects. Furthermore, adverse effects should be tolerable. If the active ingredients in a medication are substantial and intolerable, the drug is usually discontinued. According to the FDA: "An active ingredient is any component that provides a pharmacological activity or other direct effects in the diagnosis, cure, mitigation, treatment, or prevention of disease, or to affect the structure or any function of the body of man or animals." Active ingredients are also known as therapeutically active ingredients or pharmaceutically active ingredients. In addition to active ingredients, medications also contain inactive ingredients, such as colors, binders, and preservatives. Hero Images / Getty Images Example of Active Ingredient: Sertraline Hydrochloride The active ingredient in Zoloft, or sertraline, a prescription medication used to treat depression, is sertraline hydrochloride. Sertraline hydrochloride is slightly soluble in water. Sertraline inhibits the uptake of serotonin by blood platelets in the brain. Sertraline likely has little effect on other neurotransmitters, such as dopamine and norepinephrine. Adverse effects of sertraline can include the following: DizzinessSkin rashNervousnessInsomniaNauseaDiarrheaConstipationUpset stomachHeadacheStomach painChanges in appetiteSexual dysfunctionDry mouthWeight loss Zoloft is a selective serotonin reuptake inhibitor (SSRI) used to treat major depressive disorder, obsessive-compulsive disorder, panic disorder, PTSD, premenstrual dysmorphic disorder and social anxiety disorder. Sometimes the active ingredients of two (or more) medications interact in dangerous ways. For example, when Zoloft is mixed with the psychiatric medications monoamine oxidase inhibitors (MAOIs) very bad things can happen including rigidity, myoclonus, hyperthermia, changes in vital signs, irritability, extreme agitation, delirium, and coma. The resulting clinical presentation is similar to the neuroleptic malignant syndrome. Of note, neuroleptic malignant syndrome presents as muscular rigidity, autonomic instability, fever and mental status changes in people who are taking atypical antipsychotics. Other Examples of Active Ingredients The active ingredient in Prilosec, an over-the-counter medication used to treat GERD (heartburn), is omeprazole magnesium. The active ingredient in BJ's Allergy Medicine, an over-the-counter medication used to treat nasal allergies, is diphenhydramine HCL, which is also sold under the brand name Benadryl. Content edited by Naveed Saleh, MD, MS Was this page helpful? Thanks for your feedback! Sign up for our Health Tip of the Day newsletter, and receive daily tips that will help you live your healthiest life. Sign Up You're in! Thank you, {{form.email}}, for signing up. There was an error. Please try again. What are your concerns? Other Inaccurate Hard to Understand Submit Article Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Burstein A, Talmi A, Stafford B, Kelsay K. Child & Adolescent Psychiatric Disorders & Psychosocial Aspects of Pediatrics. In: Hay WW, Jr., Levin MJ, Deterding RR, Abzug MJ. eds. CURRENT Diagnosis & Treatment: Pediatrics, 22e. New York, NY: McGraw-Hill; 2013. Satterfield JM, Feldman MD. Anxiety. In: Feldman MD, Christensen JF, Satterfield JM. eds. Behavioral Medicine: A Guide for Clinical Practice, 4e. New York, NY: McGraw-Hill; 2014. Selected Sources