A MILD headache, a stiff joint, maybe the loosies. The first stop for most of us affected by these common health irritants is the chemist, not the doctor. And even if the strip of tablets clearly says it’s a Schedule H drug, no shop boy will refuse to sell paracetamol or antihistamines.So, say the experts, it’s the consumer who needs to be cautious. Stick to the correct dosage for the right length of time. Call on a doctor if the symptoms worsen. But first, read our checklist. What are OTC drugs?Over-the-counter (OTC) drugs are non-prescription medicines (as opposed to Rx or prescription drugs) sold in convenience stores, groceries and health shops. They include pain relievers, cough and cold remedies, sleeping aids, weight-reducing aids, vitamin supplements et al, usually available as syrups, pills or ointments. About 50 per cent of senior citizens regularly use OTC drugs. What’s the catch?They are not as safe as their easy accessibility would make you believe. There have been reports that chemicals or substances used in some OTC drugs have psychoactive effects, which impair the central nervous system. ‘‘Large doses of OTC drugs can be very toxic. Every person must know what she or he is taking. Instead of brand names, one has to be familiar with the constituents of the drug,’’ says Dr CM Gulati, editor of the Monthly Index of Medical Specialities (MIMS). ‘‘OTCs may impair the ability to drive safely because they can make one drowsy or, conversely, excited. When combined with other drugs, stronger side-effects can result, or the effectiveness of the drug can be reduced.’’ How can they be abused?‘‘The drugs can be harmful in two ways. One, if the patient is contraindicative, and two, if the patient is overdoing the drugs. While overdoing causes toxicity, a contraindicative patient will suffer long-term effects,’’ says Gulati. DIY DOSE At the chemist • Buy the entire strip and read the patient information leaflet that comes with it. • On the label, look for product name, active ingredients, purpose (product category, such as antihistamine, antacid, analgesic), uses, warnings, directions and other information. •Check the outer packaging for evidence of tampering. At home • Avoid alcohol if you are taking antihistamines, cough or cold products containing dextromethorphan, or drugs treating sleeplessness. • Do not use drugs that cause sleeplessness (Coldarin, for instance) if you are on prescription sedatives. • Check with your doctor before taking products containing aspirin if you’re on a prescription blood thinner, have diabetes or gout.