November 3, 2025 Author : Ana Filipa Mourão (rheumathology) Biological medicine are relatively recent and considered one of the most significant advances of the last decades in the treatment of many diseases. They are a therapeutic option for several chronic inflammatory, autoimmune, and oncological diseases, some of which are quite complex, debilitating, and sometimes life-threatening. What are biological medicines? Are produced by or from living organisms (like bacteria, viruses, animal or plant cells) using biotechnology techniques, whereas traditional drugs are obtained through chemical synthesis. Have very specific targets (e.g., immune system molecules or cells involved in a disease process) and a recognized efficacy, even when conventional drugs used for the same disease do not or no longer have it. The first biological drug produced through biotechnology was human recombinant insulin, in the 1980s. Since then, many others have emerged, including monoclonal antibodies and drugs used in gene therapy. Diseases for which biological medicines may be indicated Currently, biologics are used worldwide , primarily in rheumatology, gastroenterology, pulmonology, dermatology, and oncology, including: Rheumatic diseases: rheumatoid arthritis, spondyloarthritis such as ankylosing spondylitis and psoriatic arthritis, Sjogren syndrome, systemic lupus erythematosus, among others, with the aim of reducing inflammation, pain, and joint stiffness, and halting disease progression. Dermatological diseases: moderate to severe psoriasis and resistant atopic dermatitis, by blocking the inflammatory mediators that trigger skin lesions. Digestive diseases: Crohn disease and ulcerative colitis, to induce and maintain remission, reducing the frequency of inflammatory flares and decreasing the likelihood of a surgery. Respiratory diseases: severe asthma that cannot be controlled with standard treatments. Oncological diseases: lymphoma, leukemia, breast cancer, lung cancer, among others, to act against specific tumor cells or strengthen the immune system response. When are biological medicines prescribed? Except for some cancers, biological medications are not a first-line option, meaning they are not the first-line treatment for a disease. In most cases, they are prescribed when : The response to conventional medications was inadequate; There are contraindications to the recommended first-line treatment; First-line medications had serious side effects or adverse effects; The disease is diagnosed at an advanced stage or progresses rapidly, justifying an earlier option than the usual one for biological medicines. Treatment with biological medicines Biological medicines act on the immune system – they are immunosuppressants. People undergoing treatment with immunosuppressive medications are immunocompromised, meaning their immune system is weakened, making them more vulnerable to infections, even those that their body would normally resolve easily. Therefore, anyone undergoing treatment with biological medicines, regardless of the disease, will always require more frequent medical monitoring before and during treatment and, depending on the case, throughout the patient lives. Furthermore, patients must play an even more active role in prevention and monitoring their health. Monitoring before, during, and after treatment In addition to medical follow-up and disease-specific tests, before starting treatment with biological medicines, tests are performed, including some designed to screen for infections, such as tuberculosis, viral hepatitis, and human immunodeficiency virus infection, among others. If an infection is present, it should be treated before starting treatment with biological medicines. Due to the increased risk of infection during treatment, vaccination status must also be up-to-date , and vaccines may be prescribed and should be administered before starting treatment to reduce the likelihood of various diseases, such as pneumonia or hepatitis. Biological medicines can be administered orally or by injection (intravenous or subcutaneous). In some cases (subcutaneous), the injection is administered by the patient themselves. In this case, the first treatment is usually supervised by a nurse who teaches the patient how to self-administer the medication and reviews with them the signs to watch for and the precautions to take. The duration of treatment with biological medications depends on the disease, the patient, and the medication. Monitoring throughout the treatment period is essential to assess efficacy and ensure the safety of the medication. This means attending regular appointments and undergoing all tests and other diagnostic exams prescribed. Once treatment, which can last months or years, is completed, it is normal to maintain regular medical supervision to ensure disease control and to act early if necessary. The active role of the patient is irreplaceable Comply with the treatment as directed, maintaining the proposed medical follow-up, monitoring for signs of infection, and adopting healthy habits are the responsibilities of patients that help ensure the safety and efficacy of biological medicines. The following are important general precautions for any treatment with biological medications: Treatment should not be interrupted or changed without medical advice , as this could compromise efficacy or cause adverse effects. Be particularly alert to signs of fever, persistent cough, unusual symptoms, or non-healing wounds, and seek medical attention if these occur, always mentioning the current medication. Always report in medical appointments the biological therapy , including in the urgent care service, before surgery, dental procedures, or any invasive procedure. Increase hygiene precautions , including regular hand washing because hands frequently and unintentionally touch the eyes and mouth. Go to a dental appointment before starting biological treatment to treat cavities or any source of infection. Avoid contact with sick people , including those with respiratory symptoms such as coughing or sneezing. Avoid crowded places or, if not possible, wear a protective mask. Avoid travel to regions with endemic infections and/or poor sanitation. Avoid smoking and alcoholic beverages , as they can interfere with medications and, in inflammatory diseases, increase inflammation. Eat a complete, diverse, and balanced diet , as well as regular exercise, which strengthens the immune system and plays a direct role in controlling some diseases. For example, swimming and flexibility and stretching exercises are essential for maintaining the quality of life of patients with inflammatory spine joint diseases. As with conventional medications, some biological medicines cannot be taken (by the mother or father) while planning a pregnancy. In this case, it is essential to inform the doctor, who can advise whether it is necessary and for how long to discontinue or change the treatment before beginning attempts to conceive. Meet the rheumathology clinical team from Hospital da Luz network. The content published in the Health Guide is intended for the general public and is provided for informational and educational purposes only. It does not replace individual medical assessment, diagnosis, or personalized clinical advice from a qualified healthcare professional. The content is produced or reviewed by physicians and other healthcare professionals at Hospital da Luz and is based on the knowledge available at the time of publication or the most recent update, as indicated at the beginning of each item.
