pharyngeal pouchSee oesophageal di-
verticulum.
pharyngitisAcute or chronic inflam-
mation of the pharynx, causing a sore
throat. Causes of pharyngitis include viral
and bacterial infections. Swallowing sub-
stancesthat scald, corrode, or scratch
the lining of the throat, and smoking,
may also cause pharyngitis.
As well as a sore throat, there may
be discomfort when swallowing, slight
fever, earache, and swollen lymph nodes
in the neck.
Gargling with warm salt water and tak-
ing analgesic drugs is usually the only
treatment needed. If the sore throat is
severe or prolonged a doctor may take a
throat swaband prescribe antibiotic drugs.
pharynxThe passage that connects the
back of the mouth and nose to the oeso-
phagus. The upper part, or nasopharynx,
connects the nasal cavity to the area
behind the soft palate. The middle part,
the oropharynx, runs from the naso-
pharynx to below the tongue. The lower
part, called the laryngopharynx, lies
behind and to each side of the larynx.
pharynx, cancer ofA cancerous tumour
of the pharynx. Pharyngeal cancer usu-
ally develops in the mucous membrane
lining. In the West, almost all cases of
pharyngeal cancer are related to smoking
and to drinking alcohol. The incidence
rises with age, and the disorder is more
common in men.
Cancerous tumours of the oropharynx
(the middle section of the pharynx) usu-
ally cause difficulty swallowing, often
with a sore throat and earache. Blood-
stained sputum may be coughed up.
Sometimes there is only the feeling of a
lump in the throat or a visible enlarged
lymph nodein the neck. Cancer of the
laryngopharynx (the lowermost part of
the pharynx) initially causes a sensation
of incomplete swallowing, then a muf-
fled voice, hoarseness, and increased
difficulty in swallowing. Tumours of the
nasopharynxhave different causes.
Diagnosis of cancer of the pharynx is
made by biopsy, often in conjunction
with laryngoscopy, bronchoscopy, or oeso-
phagoscopy. The growth may be removed
surgically or treated with radiotherapy.
Anticancer drugsmay also be given.phencyclidineA drug of abuse, com-
monly known as angel dust or PCP.
phenelzineA monoamine oxidase inhib-
itor antidepressant drugusually given
when other antidepressant drugs are
ineffective. Possible side effects include
dizziness, drowsiness, and rash, and,
when taken with certain foods or other
drugs, a dangerous rise in blood pressure.
phenobarbitalA barbiturate drug used
mainly as an anticonvulsant. It is often
used with phenytointo treat epilepsy.
Possible side effects include drowsi-
ness, clumsiness, dizziness, excitement,
and confusion.
phenothiazine drugsA group of drugs
used to treat psychotic illnesses (see
antipsychotic drugs) and to relieve severe
nausea and vomiting (see antiemetic
drugs). The group includes chlorpro-
mazine, fluphenazine, and perphenazine.
phenoxymethylpenicillinA synthetic
penicillin drug, which is an antibiotic
prescribed to treat bacterial infections
including pharyngitis, tonsillitis, and
tooth abscess.
Possible adverse effects include rash
and nausea. A few people develop a
serious allergic reaction in which there
is wheezing, breathing difficulty, and
swelling around the mouth and eyes.
phenylbutazoneA nonsteroidal anti-
inflammatory drug (NSAID) used to
relieve the symptoms of ankylosing
spondylitis. Phenylbutazone may cause
nausea, fluid retention, rash, and peptic
ulcer. It may also increase the risk of
blood disorders. It is prescribed only
under hospital supervision, when other
drugs are ineffective.
phenylephrineA decongestant drug
used to treat seasonal allergic rhinitis
(hay fever) and the common cold. As
eye-drops, it is used to dilate the pupils
for eye examinations. High doses or pro-
longeduse of nasal preparations may
cause headache and blurred vision;
stopping taking the drug suddenly may
make nasal congestion worse.
phenylketonuriaAn inherited disorder
in which the enzymethat converts the
amino acidphenylalanine into tyrosine
(another amino acid) is defective. Unless
phenylalanine is excluded from the diet,
it builds up in the body and causesPHARYNGEAL POUCH PHENYLKETONURIAP