British National Formulary
Wordings which can be given as separate warnings are labels 1-19 and labels 29-33. Wordings which can be incorporated in an appropriate position in the directions for dosage or administration are labels 21-28. A label has been omitted for number 20.
If separate labels are used it is recommended that the wordings be used without modification. If changes are made to suit computer requirements, care should be taken to retain the sense of the original.
To be used on preparations for children containing antihistamines, or other preparations given to children where the warnings of label 2 on driving or alcohol would not be appropriate.
To be used on preparations for adults that can cause drowsiness, thereby affecting the ability to drive and operate hazardous machinery; label 1 is more appropriate for children. It is an offence to drive while under the influence of drink or drugs.
Some of these preparations only cause drowsiness in the first few days of treatment and some only cause drowsiness in higher doses.
In such cases the patient should be told that the advice applies until the effects have worn off. However many of these preparations can produce a slowing of reaction time and a loss of mental concentration that can have the same effects as drowsiness.
Avoidance of alcoholic drink is recommended because the effects of CNS depressants are enhanced by alcohol. Strict prohibition however could lead to some patients not taking the medicine. Pharmacists should therefore explain the risk and encourage compliance, particularly in patients who may think they already tolerate the effects of alcohol (see also label 3). Queries from patients with epilepsy regarding fitness to drive should be referred back to the patient's doctor.
Side-effects unrelated to drowsiness that may affect a patient's ability to drive or operate machinery safely include blurred vision, dizziness, or nausea. In general, no label has been recommended to cover these cases, but the patient should be suitably counselled.
To be used on preparations containing monoamine-oxidase inhibitors; the warning to avoid alcohol and dealcoholised (low alcohol) drink is covered by the patient information leaflet.
Also to be used as for label 2 but where alcohol is not an issue.
To be used on preparations where a reaction such as flushing may occur if alcohol is taken (e.g. metronidazole and chlorpropamide). Alcohol may also enhance the hypoglycaemia produced by some oral antidiabetic drugs but routine application of a warning label is not considered necessary.
To be used with label 25 on preparations coated to resist gastric acid (e.g. enteric-coated tablets). This is to avoid the possibility of premature dissolution of the coating in the presence of an alkaline pH.
Label 5 also applies to drugs such as ketoconazole where the absorption is significantly affected by antacids; the usual period of avoidance recommended is 2 to 4 hours.
To be used on preparations containing ofloxacin and some other quinolones, doxycycline, lymecycline, minocycline, and penicillamine. These drugs chelate calcium, iron and zinc and are less well absorbed when taken with calcium-containing antacids or preparations containing iron or zinc. These incompatible preparations should be taken 2-3 hours apart.
To be used on preparations containing ciprofloxacin, norfloxacin or tetracyclines that chelate calcium, iron, magnesium, and zinc and are thus less available for absorption; these incompatible preparations should be taken 2-3 hours apart. Doxycycline, lymecycline and minocycline are less liable to form chelates and therefore only require label 6 (see above).
To be used on preparations that contain a drug which is required to be taken over long periods without the patient necessarily perceiving any benefit (e.g. antituberculous drugs).
Also to be used on preparations that contain a drug whose withdrawal is likely to be a particular hazard (e.g. clonidine for hypertension). Label 10 (see below) is more appropriate for corticosteroids.
To be used on preparations where a course of treatment should be completed to reduce the incidence of relapse or failure of treatment.
The preparations are antimicrobial drugs given by mouth. Very occasionally, some may have severe side-effects (e.g. diarrhoea in patients receiving clindamycin) and in such cases the patient may need to be advised of reasons for stopping treatment quickly and returning to the doctor.
To be used particularly on preparations containing anticoagulants, lithium and oral corticosteroids. The appropriate treatment card should be given to the patient and any necessary explanations given.
This label may also be used on other preparations to remind the patient of the instructions that have been given.
To be used on preparations that may cause phototoxic or photoallergic reactions if the patient is exposed to ultraviolet radiation. Many drugs other than those listed in Appendix 9 (e.g. phenothiazines and sulphonamides) may, on rare occasions, cause reactions in susceptible patients. Exposure to high intensity ultraviolet radiation from sunray lamps and sunbeds is particularly likely to cause reactions.
To be used on preparations containing probenecid and sulfinpyrazone whose activity is reduced by aspirin.
Label 12 should not be used for anticoagulants since label 10 is more appropriate.
To be used on preparations that are intended to be dissolved in water (e.g. soluble tablets) or mixed with water (e.g. powders, granules) before use. In a few cases other liquids such as fruit juice or milk may be used.
To be used on preparations that may cause the patient's urine to turn an unusual colour. These include phenolphthalein (alkaline urine pink), triamterene (blue under some lights), levodopa (dark reddish), and rifampicin (red).
To be used on preparations containing sufficient flammable solvent to render them flammable if exposed to a naked flame.
To be used on glyceryl trinitrate tablets to remind the patient not to transfer the tablets to plastic or less suitable containers.
To be used on preparations for the treatment of acute migraine except those containing ergotamine, for which label 18 is used. The dose form should be specified, e.g. tablets or capsules.
It may also be used on preparations for which no dose has been specified by the prescriber.
To be used on preparations containing ergotamine. The dose form should be specified, e.g. tablets or suppositories.
To be used on preparations containing hypnotics (or some other drugs with sedative effects) prescribed to be taken at night. On the rare occasions (e.g. nitrazepam in epilepsy) when hypnotics are prescribed for daytime administration this label would clearly not be appropriate. Also to be used as an alternative to the label 2 wording (the choice being at the discretion of the pharmacist) for anxiolytics prescribed to be taken at night.
It is hoped that this wording will convey adequately the problem of residual morning sedation after taking 'sleeping tablets'.
To be used on preparations that are liable to cause gastric irritation, or those that are better absorbed with food.
Patients should be advised that a small amount of food is sufficient.
To be used on some preparations whose absorption is thereby improved. Most oral antibacterials require label 23 instead (see below).
To be used on oral preparations whose absorption may be reduced by the presence of food and acid in the stomach.
To be used on preparations that should be sucked or chewed.
The pharmacist should use discretion as to which of these words is appropriate.
To be used on preparations that are enteric-coated or designed for modified-release.
Also to be used on preparations that taste very unpleasant or may damage the mouth if not swallowed whole.
To be used on preparations designed for sublingual use. Patients should be advised to hold under the tongue and avoid swallowing until dissolved. The buccal mucosa between the gum and cheek is occasionally specified by the prescriber.
To be used on preparations that should be well diluted (e.g. chloral hydrate), where a high fluid intake is required (e.g. sulphonamides), or where water is required to aid the action (e.g. methylcellulose). The patient should be advised that 'plenty' means at least 150 mL (about a tumblerful). In most cases fruit juice, tea, or coffee may be used.
To be used on external preparations that should be applied sparingly (e.g. corticosteroids, dithranol).
To be used on containers of dispensed solid dose preparations containing paracetamol for adults when the instruction on the label indicates that the dose can be taken on an 'as required' basis. The dose form should be specified, e.g. tablets or capsules.
This label has been introduced because of the serious consequences of overdosage with paracetamol.
To be used on all containers of dispensed preparations containing paracetamol.
To be used on all containers of dispensed preparations containing aspirin and paracetamol.
To be used on containers of dispensed preparations containing aspirin when the name on the label does not include the word 'aspirin'.
To be used on containers of dispensed preparations containing aspirin derivatives.
