sprays. Generally, corticosteroids are most effec-
tive when taken on a regular schedule to prevent
the inflammatory process from developing,
though they also can help suppress an inflamma-
tory response after it begins. Because long-term
corticosteroid therapy also suppresses the function
of the adrenal glands, the body stops producing
cortisol and becomes dependent on the external
source of corticosteroids (the medication). It is
important to reduce the dose over time (taper)
when stopping a systemic corticosteroid, to allow
the adrenal glands to resume cortisol production.
Suddenly stopping systemic corticosteroid therapy
can result in a rebound syndrome, with symptoms
of inflammation, PAIN, and FEVER.
Risks and Side Effects
Side effects are uncommon with short-term sys-
temic (oral and injection forms), inhalation, or
topical corticosteroid use. However, corticosteroids
tend to be less effective with repeated or chronic
use. Injected corticosteroids, such as to treat
inflammation in joints, can cause tissue damage
over time. Doctors generally limit corticosteroid
injections to prevent such damage. Long-term use
of inhaled corticosteroids is often irritating to the
tissues of the NOSEor THROAT. Long-term topical
corticosteroids can cause thinning and darkening
of the SKIN.
Long-term systemic corticosteroid therapy, such
as for immunosuppression or to treat severe
autoimmune disorders, has numerous side effects
that require close monitoring to maintain optimal
health. Key among them are increased risks for
type 2 DIABETESand OSTEOPOROSIS. Systemic corti-
costeroids alter the body’s hormonal balance and
interactions, affecting numerous endocrine func-
tions such as regulatory mechanisms for
INSULIN–GLUCOSE METABOLISMand calcium balance
in the bones. Systemic corticosteroids also influ-
ence thyroid hormones, which may alter overall
metabolism to result in side effects such as rapid
weight gain (with a characteristic rounded face)
and excessive tiredness. Some people experience
mood swings, mood disorders, DEPRESSION, or GEN-
ERAL ANXIETY DISORDER (GAD) when taking long-
term corticosteroid therapy, a consequence of the
influence corticosteroids exert on BRAIN neuro-
transmitters.
Because they suppress the immune response
and LEUKOCYTE(white blood cell) production, sys-
temic corticosteroids also increase the risk for
infection. Chronic COLDS, URINARY TRACT INFECTION
(UTI), CANDIDIASIS (yeast infection), and wounds
that are slow to heal are common with long-term
systemic corticosteroid therapy. Early treatment
with ANTIBIOTIC MEDICATIONSorANTIFUNGAL MEDICA-
TIONScan help the body fight such infections. Sys-
temic corticosteroids interact with numerous
other medications and, because they cause sodium
and fluid retention, may increase BLOOD PRESSURE
or cause HYPERTENSION.
See also BONE; CUSHING’S SYNDROME; DRUG INTER-
ACTION; 5 - AMINOSALICYLATE( 5 ASA) MEDICATIONS; NEU-
ROTRANSMITTER; NONSTEROIDAL ANTI-INFLAMMATORY
DRUGS (NSAIDS); OPPORTUNISTIC INFECTION; ORGAN
TRANSPLANTATION; PSYCHOSIS; THYROID GLAND; WOUND
CARE.cytokines A large family of proteins that mediate
and regulate the IMMUNE RESPONSE. Leukocytes
(white BLOODcells) produce cytokines. There are
more than 100 cytokines, which may act inde-
pendently or synergistically with other cytokines.
Among the actions of cytokines are cell homing
and direction (drawing leukocytes to the site of
INFECTIONor injury), INFLAMMATIONresponse, and
stimulation of the numerous molecules that par-
ticipate in the immune response. Cytokines may
act on the cells that produce them (autocrine
activity), on cells in proximity to them (paracrine
activity), or on cells throughout the body
(endocrine activity).MAJOR TYPES OF CYTOKINES
CHEMOKINES COLONY-STIMULATING FACTORS(CSFS)
ERYTHROPOIETIN(EPO) INTERFERONS
INTERLEUKINS LYMPHOKINES
MONOKINES TUMOR NECROSIS FACTORS(TNFS)See also ANTIBODY; ANTIGEN; CELL-MEDIATED IMMU-
NITY; HISTAMINE; HORMONE; LEUKOCYTE; LEUKOTRIENES.cytokines 257