Examples of these include some sleep aid tablets such as Nytol , human deworming tablets such as Mebendazole , painkillers with small amounts of codeine (up to mg per tablet), and pseudoephedrine . Medication available only with a prescription is marked somewhere on the box/container with [POM]. Pharmacy-only products are marked with [P]. A prescription is not required for [P] medicines, and pharmacy sales assistants are required by Royal Pharmaceutical Society codes to ask certain questions, which varies for what the customer says. If they ask for a specific product, the pharmacy assistant must ask "Who is it for," "How long have you had the symptoms," "Are you allergic to any medication," "Are you taking any medication" ('WHAM' questions). If a customer asks for a remedy, ., hay fever, then the two WHAM questions must be followed "Who is it for," "What are the symptoms," "How long have you had the symptoms," "Have you taken any action towards your symptoms," and "Are you taking any other medication." It is with this information that the pharmacist can halt the sale, if need be. No [POM], [P] or [GSL] products that are stocked in a pharmacy can be sold, dispensed, or pre-made until a responsible pharmacist is signed in and on the premises. Some medication available in supermarkets and petrol stations is sold only in smaller packet sizes. Often, larger packs will be marked as [P] and available only from a pharmacy. Frequently, customers buying larger-than-usual doses of [P] medicines (such as DXM , promethazine, codeine or Gee's linctus) will be queried, due to the possibility of abuse. 
Studies show some of the chemicals in coal tar may cause cancer, but only in very high concentrations, such as in what is used in industrial paving. Anyone using tar regularly should follow a regular skin cancer checkup schedule. California requires OTC coal tar shampoos, lotions and creams that contain more than percent coal tar to be labeled with cancer warnings. However, the FDA maintains that OTC products with coal tar concentrations between percent and 5 percent are safe and effective for psoriasis, and there is no scientific evidence that the tar in OTC products is carcinogenic.
Although manufacturers are required to provide appropriate OTC labeling for products classified as OTC medications, patients who are inexperienced in the interpretation of medication labels may have difficulty reading and understanding label instructions. 11 This difficulty could result in misuse of the product, leading to adverse events or drug interactions with prescription medications or other OTC medications. 12 Another concern with reclassified products is that their use may delay effective treatment of more serious medical disorders because symptoms are relieved by an OTC medication. To help prevent these problems, health care professionals should be prepared to effectively counsel patients regarding appropriate use of OTC medications.