tachycardia. Procainamide may cause
nausea, vomiting, loss of appetite, and,
rarely, confusion. Prolonged treatment
may induce lupus erythematosus.
procaineA local anaesthetic (see an-
aesthesia, local).
procarbazineAn anticancer drugused
most often in Hodgkin’s disease. Side
effects are typical of anticancer drugs.
prochlorperazineA phenothiazine-type
antipsychotic drugused to relieve symp-
toms of certain psychiatric disorders,
such as schizophreniaand mania. It is
also used in small doses as an antiemetic
drug. It may cause involuntary move-
ments of the face and limbs, lethargy,
dry mouth, blurred vision, and dizziness.
procidentiaA medical term for severe
prolapse, usually of the uterus.
proctalgia fugaxA severe cramping
pain in the rectumunconnected with any
disease. It may be due to muscle spasm.
The pain is of short duration and sub-
sides without treatment.
proctitisInflammation of the rectum,
causing soreness and bleeding, some-
times with a mucus and pus discharge.
Proctitis commonly occurs as a feature
of ulcerative colitis, Crohn’s disease, or
dysentery. In cases where inflammation
is confined to the rectum, the cause is
often unknown. In male homosexuals,
proctitis is sometimes due to gonor-
rhoeaor another sexually transmitted
infection. Rare causes include tubercu-
losis, amoebiasis, and schistosomiasis.
Diagnosis is made by proctoscopy. A
biopsyis sometimes needed. Treatment
of the underlying cause usually clears
the problem. Corticosteroid drugsmay
relieve symptoms.
proctoscopyExamination of the anus
and rectumwith a proctoscope (a rigid
viewing instrument).
procyclidineAn anticholinergic drug
used to treatParkinson’s disease and
minimize the side effects of some anti-
psychotic drugs. Possible adverse effects
include dry mouth and blurred vision.
prodromeAn early warning symptom
of illness.
progeriaPremature aging. There are 2
forms of progeria, and both are very rare.
In Hutchinson-Gilford syndrome, the pre-
mature aging starts at about 4 years old,
and many features of old age, including
grey hair, balding, sagging skin, and
atherosclerosis, have developed by age
10–12. Death usually occurs at puberty.
Werner’s syndrome (adult progeria) starts
in adolescence or early adulthood and
follows the same progression. The cause
of progeria is unknown, although it is
known that the cells in affected people
reproduce far less frequently than those
in healthy people.
progesterone hormoneA female sex
hormone essential for the functioning of
the female reproductive system. Proges-
terone is made in the ovaries, and small
amounts are produced by the adrenal
glandsand testes. During the menstrual
cycle, changing progesterone levels
cause thickening of the endometrium
and menstruation. If pregnancy occurs,
progesterone is produced by the pla-
centa; a fall in its level helps to initiate
labour. Progesterone also causes
increased fat deposition and increased
sebumproduction by glands in the skin.
progestogen drugsA group of drugs
similar toprogesterone hormone. The
drugs are used in oral contraceptives,
are prescribed to treat menstrual prob-
lems (see menstruation, disorders of),
and are included in hormone replace-
ment therapy (HRT). Progestogen drugs
are also used to treat premenstrual syn-
drome, endometriosis, and
hypogonadism, and are sometimes used
as anticancer drugs. Adverse effects
include weight gain, oedema, headache,
dizziness, rash, irregular periods, breast
tenderness, and ovarian cysts.
prognathismAbnormal protrusion of
the lower jaw or both jaws.
prognosisAn assessment of the proba-
ble course and outcome of a disease.
progressiveA term used to describe a
condition that becomes more severe
and/or extensive over time.
progressive muscular atrophyA type
of motor neuron diseasein which the
muscles of the hands, arms, and legs
become weak and wasted and twitch
involuntarily. The condition eventually
spreads to other muscles.
proguanilAn antimalarial drug used in
the prevention of malaria. Side effects
are rare. Indigestion, nausea, or vomitingPROCAINE PROGUANIL
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