Drug Eruption and Interactions - PHARMACEUTICAL REVIEW

648 DESCRIPTION OF THE 34 MOST COMMON REACTION PATTERNS
Common causes of fixed eruptions are: ampicillin, aspirin,
barbiturates, dapsone, metronidazole, NSAIDs, oral contraceptives,
phenolphthalein, phenytoin, quinine, sulfonamides,
and tetracyclines.
Gingival hyperplasia
Gingival hyperplasia, a common, undesirable, non-allergic
drug reaction begins as a diffuse swelling of the interdental
papillae.
Particularly prevalent with phenytoin therapy, gingival
hyperplasia begins about 3 months after the onset of therapy,
and occurs in 30 to 70% of patients receiving it. The
severity of the reaction is dose-dependent and children and
young adults are more frequently affected. The most severe
cases are noted in young women.
In many cases, gingival hyperplasia is accompanied by
painful and bleeding gums. There is often superimposed secondary
bacterial gingivitis. This can be so extensive that the
teeth of the maxilla and mandible are completely
overgrown.
While it is characteristically a side effect of hydantoin
derivatives, it may occur during the administration of phenobarbital,
nifedipine, diltiazem and other medications.
Lichenoid (lichen planus-like) eruptions
Lichenoid eruptions are so called because of their resemblance
to lichen planus, a papulosquamous disorder that
characteristically presents as multiple, discrete, violaceous,
flat-topped papules, often polygonal in shape and which are
extremely pruritic.
Not infrequently, lichenoid lesions appear weeks or
months following exposure to the responsible drug. As a
rule, the symptoms begin to recede a few weeks following
the discontinuation of the drug.
Common drug causes of lichenoid eruptions are:
antimalarials, beta-blockers, chlorpropamide, furosemide,
gold, methyldopa, phenothiazines, quinidine, thiazides, and
tolazamide.
Lupus erythematosus
A reaction, clinically and pathologically resembling idiopathic
systemic lupus erythematosus (SLE), has been reported in
association with a large variety of drugs. There is some evidence
that drug-induced SLE, invariably accompanied by a
positive ANA reaction with 90% having antihistone antibodies,
may have a genetically determined basis. These symptoms
of SLE, a relatively benign form of lupus, recede within
days or weeks following the discontinuation of the responsible
drug. Skin lesions occur in about 20% of cases. Drugs
cause fewer than 8% of all cases of systemic LE.
The following drugs have been commonly associated with
inducing, aggravating or unmasking SLE: beta-blockers,
carbamazepine, chlorpromazine, estrogens, griseofulvin,
hydralazine, isoniazid (INH), lithium, methyldopa, minoxidil,
oral contraceptives, penicillamine, phenytoin
(diphenylhydantoin), procainamide, propylthiouracil,
quinidine, and testosterone.
Onycholysis
Onycholysis, the painless separation of the nail plate from
the nail bed, is one of the most common nail disorders.
The unattached portion, which is white and opaque, usually
begins at the free margin and proceeds proximally, causing
part or most of the nail plate to become separated. The
attached, healthy portion of the nail, by contrast, is pink and
translucent.
Pemphigus vulgaris
Pemphigus vulgaris (PV) is a rare, serious, acute or chronic,
blistering disease involving the skin and mucous membranes.
Characterized by thin-walled, easily ruptured, flaccid
bullae that are seen to arise on normal or erythematous skin
and over mucous membranes, the lesions of PV appear initially
in the mouth (in about 60% of the cases) and then
spread, after weeks or months, to involve the axillae and
groin, the scalp, face and neck. The lesions may become generalized.
Because of their fragile roofs, the bullae rupture leaving
painful erosions and crusts may develop principally over the
scalp.
Peyronie’s disease
First described in 1743 by the French surgeon, François de la
Peyronie, Peyronie’s disease is a rare, benign connective tissue
disorder involving the growth of fibrous plaques in the
soft tissue of the penis. Beginning as a localized inflammation,
it often develops into a hardened scar. Affecting as much as
1% of men, it may cause deformity, pain, cord-like lesions,
or abnormal curvature of the penis when erect.
It has been associated with several drugs, including all the
adrenergic blocking agents (beta-blockers), methotrexate,
colchicine and others.
Photosensitivity
A photosensitive reaction is a chemically induced change in
the skin that makes an individual unusually sensitive to electromagnetic
radiation (light). On absorbing light of a specific
wavelength, an oral, injected or topical drug may be chemically
altered to produce a reaction ranging from macules and
papules, vesicles and bullae, edema, urticaria, or an acute
eczematous reaction.
Any eruption that is prominent on the face, the dorsa of
the hands, the ‘V’ of the neck, and the presternal area should