arthritis. Penicillamine is also used to
treat copper, mercury, lead, or arsenic
poisoning; Wilson’s disease; and primary
biliary cirrhosis.
The possible adverse effects of peni-
cillamine can include allergic rashes,
itching, nausea, vomiting, abdominal
pain, loss of taste, blood disorders, and
impaired kidney function.
penicillin drugsA group of antibiotic
drugs. Natural penicillins are derived
from the mould PENICILLIUM; others are
synthetic preparations. Penicillins are
used to treat many infective conditions,
including tonsillitis,bronchitis, bacterial
endocarditis, syphilis, and pneumonia.
They are also given to prevent rheumatic
feverfrom recurring. Common adverse
effects of penicillins are an allergic reac-
tion causing a rash, and diarrhoea.
penile implantA prosthesisinserted
into the penisto help a man suffering
from permanent impotenceto achieve
intercourse. The various types include a
silicone splint inserted in the tissues of
the upper surface of the penis, and an
inflatable prosthesis that is inflated by
squeezing a small bulb in the scrotum.
penile wartsSee warts, genital.
penisThe male sex organ through which
urineand semenpass. The penis consists
mainly of 3 cylindrical bodies of erectile
tissue (spongy tissue full of blood ves-
sels) that run along its length. Two of
these bodies, the corpora cavernosa, lie
side by side along the upper part of the
penis. The 3rd body, the corpus spon-
giosum, lies centrally beneath them and
expands at the end to form the glans.
Through the centre of the corpus spon-
giosum runs the urethra, a narrow tube
that carries urine and semen out of the
body through an opening at the tip of
the glans. Around the erectile tissue is a
sheath consisting of fibrous connective
tissue enclosed by skin. Over the glans,
the skin forms a fold called the foreskin.
penis, cancer ofA rare type of cancer-
ous tumour that is more common in
uncircumcised men with poor personal
hygiene. Viral infection and smoking
have both been shown to be additional
risk factors. The tumour usually starts
on the glansor on the foreskin as a
painless, wart-like lump or a painful
ulcer, and develops into a cauliflower-
like mass. The growth usually spreads
slowly, but in some cases it can spread
to the lymph nodesin the groin within a
few months.
Diagnosis is made by a biopsy. If the
tumour is detected early, radiotherapy is
usually successful. Otherwise, removal of
part or all of the penis may be necessary.
pentamidine An antiprotozoal drug (see
protozoa), administered by intravenous
infusion or nebulizer to prevent and
treat pneumocystis pneumoniain immu-
nosuppressed people. Pentamidine is
also used to treat the tropical disease
leishmaniasis. Side effects may include
nausea and vomiting, dizziness, flush-
ing, rash, and taste disturbances.
pentazocineAn opioid analgesic drug
used to relieve moderate or severe pain
caused by injury, surgery, cancer, or
childbirth. It is rarely used because of
its adverse affects, which include dizzi-
ness, drowsiness, nausea, vomiting, and,
rarely, hallucinations. Drug dependence
may develop if high doses are taken for
prolonged periods.
peppermint oilAn oil obtained from
the peppermint plant MENTHA PIPERITA. It
is prescribed to relieve abdominal colic
but may cause heartburn. Peppermint
oil is also used as a flavouring in some
drug preparations.
peptic ulcerA raw area that develops
in the gastrointestinal tract as a result
of erosion by acidic gastric juice; it
most commonly occurs in the stomach
or the 1st part of the duodenum.
The major cause of peptic ulcers is
HELICOBACTER PYLORIbacterial infection,
which can damage the lining of the stom-
ach and duodenum, allowing the acid
stomach contents to attack it. Analgesic
drugs,alcohol, excess acid production,
and smoking can also damage the
stomach lining. Ulcers can also form in
the oesophagus, when acidic juice from
the stomach enters it (see acid reflux),
and in the duodenum.
There may be no symptoms, or there
may be burning or gnawing pain in the
upper abdomen. Other possible symp-
toms include loss of appetite, nausea,
and vomiting. The ulcer may also bleed.
If severe, it may result in haematemesisPENICILLIN DRUGS PEPTIC ULCER
P