C H A P T E R 2 1
Antidepressant agents
331
women. As with other SSRIs, it should be used in
pregnancy only if the benefit clearly outweighs the
risk. It is taken orally, once a day.
• Moclobemide (
Amira, Aurorix
) is a MAO type A
inhibitor used for the treatment of major depressive
disorder. The drug is metabolised in the liver and
excreted through urine. The drug does cross the
placenta and enters breast milk, so it should only be
used during pregnancy and breastfeeding if the benefit
outweighs the potential risk to the neonate. This drug
is associated with CNS effects, as well as GI effects
including nausea, constipation, diarrhoea and dry
mouth.
• Mianserin (
Lumin, Tolvon
) is a tetracyclic
antidepressant, related to other TCAs, used to
manage major depression and has effective sedative
properties. Mianserin blocks alpha
2
adrenoceptors
blocking reuptake of noradrenaline, and interacts
with serotonin receptors. Mianserin has a half-life of
21 to 61 hours. It is rapidly absorbed and excreted in
the urine and faeces. Little is known about its effects
in pregnancy and breastfeeding, and it should be used
during those times only if the benefit to the mother
clearly outweighs the potential risk to the neonate.
• Mirtazapine (
Avanza
) is rapidly absorbed from the
GI tract, extensively metabolised in the liver and
excreted in the urine. Mirtazapine has a half-life
of 20 to 40 hours. How its many anticholinergic
effects relate to its antidepressive effects is not
known. Little is known about its effects in pregnancy
and breastfeeding, and it should be used during
those times only if the benefit to the mother clearly
outweighs the potential risk to the neonate.
• Reboxetine (
Edronax
) is a newer noradrenaline
reuptake inhibitor used for managing major
depression. It is rapidly absorbed with a half-life of
12 hours. Reboxetine is metabolised in the liver and
excreted in the urine. Little is known about its effects
in pregnancy and breastfeeding, and it should be used
during those times only if the benefit to the mother
clearly outweighs the potential risk to the neonate.
• Selegiline (
Eldepryl
) is a MAO type B inhibitor that
has been used for many years in the treatment of
Parkinson’s disease and for the treatment of major
depressive disorder. The drug is metabolised in the
liver and excreted through urine. A substantial increase
in selegiline bioavailability (up to threefold) occurs
when selegiline is administered with food high in fat.
The drug does cross the placenta and enters breast
milk, so it should only be used during pregnancy and
breastfeeding if the benefit outweighs the potential
risk to the neonate. This drug is associated with CNS
effects, as well as GI effects including nausea, vomiting,
dry mouth and abdominal pain.
• Venlafaxine (
Efexor
) mildly blocks the reuptake of
noradrenaline, 5HT and dopamine and has fewer
adverse CNS effects than other antidepressants. Its
popularity has increased with the introduction of
an extended-release form that does away with the
multiple daily doses that are required with the regular
form. Venlafaxine is readily absorbed from the GI
tract, extensively metabolised in the liver and excreted
in urine. Adequate studies have not been done in
pregnancy and breastfeeding, and it should be used
during those times only if the benefit to the mother
clearly outweighs the potential risk to the neonate.
TABLE 21.5
DRUGS IN FOCUS Other antidepressants
Drug name
Dosage/route
Usual indications
agomelatine (Valdoxan)
25 mg PO at night
Treatment of major depression in adults,
including relapse prevention
bupropion (Prexaton)
150 mg PO b.d. in sustained-release form
or 150–300 mg/day as a single dose of
extended-release form
Treatment of depression in adults, smoking
cessation
desvenlafaxine (Pristiq)
50 mg/day PO with or without food; range
50–200 mg/day
Treatment of major depressive disorder in
adults
mianserin (Lumin, Tolvon)
30 mg/day in three divided doses, maximum
120 mg/day
Treatment of major depression in adults
mirtazapine (Avanza)
15 mg/day PO, may be increased to a
maximum of 45 mg/day; reduce dose in
elderly people and those with renal or hepatic
dysfunction
Treatment of depression in adults
moclobemide (Amira)
300–600 mg PO daily in two divided doses
Treatment of major depression in adults
reboxetine (Edronax)
4 mg PO b.d., up to 10 mg/day
Treatment of major depression in adults
selegiline (Eldepryl)
5 mg PO b.d.
Treatment of major depressive disorder
venlafaxine (Efexor XR)
75 mg/day PO in divided doses, to 375 mg/day;
75 mg/day PO sustained-release formulation
to a maximum 225 mg/day; reduce dose with
hepatic and renal impairment
Treatment and prevention of depression
in generalised anxiety disorder; social
anxiety disorder; decreases addictive
behaviour
