T
opical agents are intended for surface
use only and are not meant for inges-
tion or injection. They may be toxic if
absorbed into the system, but they have
several useful purposes when applied
to the surface of the skin or mucous
membranes. Some forms of drugs
are prepared to be absorbed through
the skin for systemic effects. These
drugs may be prepared as transder-
mal patches (e.g. glyceryl trinitrate,
oestrogens, nicotine), which are
designed to provide a slow release
of the drug from the vehicle. Drugs
prepared for this type of admin-
istration are discussed with the
specific drug in the text and are
not addressed in this appendix.
Therapeutic actions and indications
Topical agents are used to treat a variety of disorders
in a localised area. Table C describes the usual uses
for the many different types of topical agents. Because
these drugs are designed for topical application, they are
minimally absorbed systemically and, if used properly,
should have minimal systemic effects.
Contraindications and cautions
The use of topical agents is contraindicated
in cases
of allergy to the drugs
and in the presence of open
wounds or abrasions,
which could lead to the systemic
absorption of the drugs
. Caution should be used during
pregnancy
if there is any possibility that the agent
might be absorbed
. Caution should also be used
in the
presence of any known allergy to the vehicles of prepa-
ration (creams, lotions)
.
Adverse effects
Because these drugs are not intended to be absorbed
systemically, the adverse effects usually associated with
topical agents are local effects, including local irritation,
stinging, burning or dermatitis. Toxic effects are associ-
ated with inadvertent systemic absorption.
Appendix
Topical agents
C
Care considerations
Assessment: History and examination
■
■
Screen for the presence of
any known allergy to the
drug
, which would be a contraindication to its use.
■
■
Include
screening for baseline status before
beginning therapy and for any potential adverse
effects
. Assess the following: condition of area to
be treated.
Implementation
■
■
Ensure proper administration of the drug
to
provide best therapeutic effect and least adverse
effects as follows
:
–– Apply sparingly. Some preparations come with
applicators, some should be applied while
wearing protective gloves and others are dropped
onto the site with no direct contact. Consult
information regarding the individual drug being
used for specific procedures.
–– Do not use with open wounds or broken skin,
which could lead to systemic absorption and
toxic effects
.
–– Avoid contact with the eyes,
which could be
injured by the drug
.
–– Do not use with occlusive dressings,
which could
increase the risk of systemic absorption.
■
■
Monitor the area being treated
to evaluate drug
effects on the condition being treated
.
■
■
Provide comfort measures
to help the person
tolerate drug effects
(e.g. analgesia as needed for
local pain, itching).
■
■
Provide teaching
to enhance knowledge about drug
therapy and promote compliance with the drug
regimen
:
–– Teach the person the proper administration
technique for the topical agent ordered.
–– Caution the person that transient stinging or
burning may occur.
–– Instruct the person to report severe irritation,
allergic reaction or worsening of the condition
being treated.
Evaluation
■
■
Monitor response to the drug (improvement in
condition being treated).
