[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Clinical exam](https://durgical.com/en/clinical-exam/) › [History taking and the interview](https://durgical.com/en/clinical-exam/#a-history) › Medicines, allergies and habits: tobacco, alcohol and other substances [Clinical exam](https://durgical.com/en/clinical-exam/) · [History taking and the interview](https://durgical.com/en/clinical-exam/#a-history) # Medicines, allergies and habits: tobacco, alcohol and other substances - History Knowing a patient's medicines, allergies and use of tobacco, alcohol or other substances prevents errors and explains many symptoms. Updated 2026-11-01 ## Key points - Record every medicine: prescribed, over-the-counter, herbal, supplements and contraceptives. - For each allergy note the substance and the reaction; a side effect such as nausea is not a true allergy. - Allergies are recorded in a visible place in the record; severe reactions include anaphylaxis, angioedema and bronchospasm. - Pack-years = cigarettes per day × years smoked ÷ 20. - The CAGE questionnaire has four questions; two or more positive answers suggest an alcohol problem. The WHO AUDIT has ten. - Ask about other substances (cannabis, cocaine, opioids) and the route of use, because of the risk of infection. ## What it is This part of the past history gathers the medicines the patient uses, their allergies and their substance use. It is key to safety: a poorly recorded allergy or a missed interaction causes avoidable harm. Tobacco and alcohol are major causes of illness and death worldwide, so every patient is asked about them, without judgment and with concrete questions. ## What it must include - A complete list of medicines with how they are taken and adherence. - Allergies: substance, type of reaction, date and severity; or 'no known allergies'. - Tobacco: type, amount, years, pack-years; exposure to wood smoke or second-hand smoke. - Alcohol: frequency, amount, binge episodes and the screening result. - Other substances: type, route, frequency and last use. ## How to ask - 'What medicines do you take, including those bought without a prescription, herbal products and vitamins?' - 'How and how often do you take them? Do you ever forget?' - 'Are you allergic to any medicine, food or latex? What exactly happened?' - 'Do you smoke or have you smoked? How many cigarettes a day and for how many years? Do you vape?' - 'Do you drink alcohol? How often, and how much on a typical day?' - CAGE: 'Have you felt you should cut down? Have people annoyed you by criticising your drinking?' - CAGE: 'Have you felt guilty about drinking? Have you had a drink first thing in the morning to steady your nerves or a hangover?' - 'Have you used any other substance, such as cannabis or cocaine? Ever injected?' ## Memory aid Three drawers that are always opened: what the patient takes, what harms them and what they cannot give up. ## Test yourself Think of the answer, then tap the question to see it. ## How are pack-years calculated? Multiply the number of cigarettes per day by the years of smoking and divide by 20; the result is expressed in pack-years. ## What do the four CAGE questions assess? Whether the person has felt they should cut down, been annoyed by criticism, felt guilty and needed a morning drink; two or more positive answers suggest an alcohol problem. ## Why is 'allergic to penicillin' not enough? Because the reaction must be recorded: hives or anaphylaxis are true allergies, whereas nausea is usually a side effect. ## Which products are often forgotten when asking about medicines? Over-the-counter products, herbal remedies, supplements, contraceptives and medicines the patient uses only now and then. [Add to my cards (4)](https://durgical.app/estudiar/?add=/en/clinical-exam/medicines-allergies-and-habits-tobacco-alcohol-and-other-substances/) ## Related - [Past medical, surgical, family and social history](https://durgical.com/en/clinical-exam/past-medical-surgical-family-and-social-history/) - [The clinical history: its parts and their order](https://durgical.com/en/clinical-exam/the-clinical-history-its-parts-and-their-order/) - [Comprehensive geriatric assessment: function, cognition, falls](https://durgical.com/en/clinical-exam/comprehensive-geriatric-assessment-function-cognition-falls/) ## Related conditions - [Alcohol use disorder](https://durgical.com/en/conditions/alcohol-use-disorder/) - [Anaphylaxis](https://durgical.com/en/conditions/anaphylaxis/) - [Opioid use disorder, overdose and withdrawal](https://durgical.com/en/conditions/opioid-use-disorder-overdose-and-withdrawal/) - [Chronic obstructive pulmonary disease (COPD)](https://durgical.com/en/conditions/chronic-obstructive-pulmonary-disease/) - [Lung cancer](https://durgical.com/en/conditions/lung-cancer/) [← All of the clinical exam](https://durgical.com/en/clinical-exam/) Educational content on the clinical exam; it is learned and practised under supervision. It does not replace assessment by a health professional and is not for self-diagnosis. Sources: [Drug allergies: MedlinePlus Medical Encyclopedia](https://medlineplus.gov/ency/article/000819.htm) (U.S. National Library of Medicine, 2025); [Tobacco and nicotine](https://www.who.int/news-room/fact-sheets/detail/tobacco) (World Health Organization, 2025); [Alcohol](https://www.who.int/news-room/fact-sheets/detail/alcohol) (World Health Organization, 2024); [The Alcohol Drinking History - Clinical Methods - NCBI Bookshelf](https://www.ncbi.nlm.nih.gov/books/n/cm/A2995/) (Butterworths (NCBI Bookshelf), 1990). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/clinical-exam/medicines-allergies-and-habits-tobacco-alcohol-and-other-substances/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/clinical-exam/medicines-allergies-and-habits-tobacco-alcohol-and-other-substances/