Bma Illustrated Medical Dictionary

flecainideAn antiarrhythmic drugused

in the treatment of tachycardia, atrial

fibrillation, and arrhythmiasassociated

with conditions such as Wolff–Parkinson–

White syndrome (a congenital abnormal-

ity of heart-rhythm). It is given, as tablets

or injection, to people resistant to or

intolerant of other treatment; and treat-

ment is always initiated in hospital. Side

effects may include dizziness, visual dis-

turbances, and worsening, or a new type

of, arrhythmia. Rarely, nausea, vomiting,

urticaria, vertigo, and jaundice occur.

fliesSee insects and disease.

floatersFragments perceived to be float-

ing in the field of vision. Floaters move

rapidly with eye movement but drift

slightly when the eyes are still. They do

not usually affect vision. Most floaters

are shadows cast on the retina by

microscopic structures in the vitreous

humour(the jelly-like substance behind

the lens). The sudden appearance of a

cloud of dark floaters, especially when

accompanied by light flashes, suggests

retinal tearor retinal detachment. A large

red floater that obscures vision is usu-

ally due to a vitreous haemorrhage.

floodingA technique used in behaviour

therapyfor treating phobias.

floppy infant A description of a baby

whose muscles lack normal tension or

tone (see hypotonia in infants).

floppy valve syndromeSee mitral

valve prolapse.

flossing, dentalThe removal of plaque

(see plaque, dental) and food particles

from around the teeth and gums by

using soft nylon or silk thread or tape.

Dental floss may be waxed or unwaxed.

Flossing should be carried out as an ad-

junct to toothbrushing.

fluSee influenza.

flucloxacillinA penicillin drugusually

used to treat staphylococcal infections.

fluconazoleAn antifungal drugused to

treat candidiasis, a fungal infection com-

monly affecting the vagina or mouth. It

may cause nausea and diarrhoea.

fluctuantA term used to describe the

movement within a swelling when it is

examined by touch. It is a sign that the

swelling contains fluid. The term is

often used to describe an abscess.

fluid retentionExcessive accumulation

of fluid in body tissues. Mild fluid reten-

tion is common with premenstrual

syndrome but disappears with the onset

of menstruation. However, more severe

fluid retention may be associated with

an underlying heart, liver, or kidney dis-

order (see ascites; nephrotic syndrome;

oedema). Diuretic drugsmay be used to

treat the condition.

flukeA type of flattened worm, also

known as a trematode, that may infest

humans or animals. The 2 main diseases

caused by flukes are liver fluke infestation,

which occurs worldwide, and schistoso-

miasis, a debilitating tropical disease.

flunitrazepamA type of benzodiazepine

drugused as a sleeping drug to treat

insomnia. The effects of flunitrazepam

may persist the following day; and pro-

longed use may result in dependence.

fluoresceinA harmless orange dye used

in ophthalmologyas an aid to the diag-

nosis of certain eye disorders.

fluoridationThe addition of fluorideto

the water supply as a means of reducing

the incidence of dental caries.

fluorideA mineral that helps to prevent

dental cariesby strengthening tooth en-

amel (see teeth), making it more resistant

to acid attacks. Fluoride may also reduce

the acid-producing ability of micro-

organisms in plaque. In the UK, fluoride

is added to the water supply; it can also

be applied directly to the teeth as part

of dental treatment or used in the form of

mouthwashes or toothpastes. Ingestion

of excess fluoride during tooth forma-

tion can lead to fluorosis.

FLECAINIDE FLUORIDE

F

Dental floss

Floss curved

around tooth

DETAIL

FLOSSING, DENTAL