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P A R T 4
Drugs acting on the central and peripheral nervous systems
(
Luvox
); paroxetine (
Aropax
); and sertraline (
Xydep
,
Zoloft
).
Therapeutic actions and indications
The action of SSRIs blocking the reuptake of 5HT
increases the levels of 5HT in the synaptic cleft and may
contribute to the antidepressant and other effects attrib
uted to these drugs.
SSRIs are indicated for the treatment of depression,
OCDs, panic attacks, bulimia, premenstrual dysphoric
disorder (PMDD), posttraumatic stress disorders, social
phobias and social anxiety disorders. A period of up to
4 weeks is necessary for realisation of the full therapeutic
effect. People may respond well to one SSRI and yet
show little or no response to another one. The choice of
drug depends on the indications and individual response.
Box 21.3 provides more information. Ongoing investi
gations are focusing on the use of these antidepressant
drugs in the treatment of other psychiatric disorders (see
Table 21.4).
Pharmacokinetics
The SSRIs are well absorbed from the GI tract, meta
bolised in the liver and excreted in the urine and faeces.
The half-life varies widely with the drug being used.
Contraindications and cautions
The SSRIs are contraindicated in the presence of allergy
to any of these drugs
because of the risk of hypersensi-
tivity reactions.
Caution should be used in people with
impaired renal or hepatic function
that could alter the
metabolism and excretion of the drug, leading to toxic
effects
, or with diabetes,
which could be exacerbated by
the stimulating effects of these drugs.
Caution should
also be used with severely depressed or suicidal people,
especially children and adolescents,
because of a risk of
TABLE 21.4
DRUGS IN FOCUS Selective serotonin reuptake inhibitors
Drug name
Dosage/route
Usual indications
citalopram (Cipramil)
20 mg/day PO b.d., up to 60 mg/day may be
needed
Treatment of depression in adults has
also been used to treat panic disorder,
premenstrual dysphoric disorder (PMDD),
obsessive-compulsive disorders (OCDs),
social phobias, trichotillomania and
posttraumatic stress disorders
duloxetine (Cymbalta)
30 mg/day PO, up to 120 mg/day if needed
Treatment of major depressive disorder
and management of neuropathic pain
associated with diabetic peripheral
neuropathy
escitalopram (Lexapro)
10 mg/day PO as a single dose; 10–20 mg/day
PO maintenance
Treatment of major depressive disorder,
maintenance of people with major
depressive disorder and generalised
anxiety disorder
fluoxetine (Prozac,
Sarafem, Lovan)
20–80 mg/day PO in the am; do not exceed
60 mg/day; reduce dose with hepatic
impairment; also available in a 90-mg,
once-a-week formulation
Treatment of depression, bulimia, OCDs,
panic disorders, PMDD in adults; also
under investigation for treatment of other
psychiatric disorders, including obesity,
alcoholism, chronic pain and various
neuropathies
fluvoxamine (Luvox)
Adult: 50 mg PO at bedtime to a maximum
of 300 mg/day; reduce dose with hepatic
impairment
Paediatric (8–17 years): 25 mg PO at bedtime;
do not exceed 250 mg/day
Treatment of OCDs; also under
investigation for treatment of depression,
bulimia, panic disorder and social phobia
paroxetine (Aropax)
10–20 mg/day PO; do not exceed 50 mg/day;
reduce dose in hepatic or renal dysfunction
and with the elderly
Treatment of depression, OCDs, PMDD,
posttraumatic stress reaction, social
anxiety disorders, general anxiety
disorders and various panic disorders
in adults; also under investigation for
treatment of chronic headache, diabetic
neuropathy and hot flushes
sertraline (Xydep, Zoloft)
Adult: 50–200 mg/day PO; reduce dose with
hepatic dysfunction, OCD
Paediatric: 25–50 mg/day PO based on age
and severity of OCD
Treatment of depression, OCDs, social
anxiety disorder, posttraumatic stress
disorder, panic disorders and PMDD
