C H A P T E R 2 0
Anxiolytic and hypnotic agents
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desirable in people who are restless, nervous, irritable
or overreacting to stimuli. Although sedation is anxio-
lytic, it may frequently lead to drowsiness. For example,
sedative-induced drowsiness is a concern for outpatients
who need to be alert and responsive in their normal
lives. On the other hand, this tiredness may be desirable
for people who are about to undergo surgery or other
procedures and who are receiving medical support. The
choice of an anxiolytic drug depends on the situation in
which it will be used, keeping the related adverse effects
in mind.
Hypnosis
Extreme sedation results in further central nervous
system (CNS) depression and sleep, or
hypnosis
. Hyp-
notics are used to help people fall asleep by causing
sedation. Drugs that are effective hypnotics act on the
reticular activating system (RAS) and block the brain’s
response to incoming stimuli. Hypnosis, therefore, is the
extreme state of sedation, in which the person no longer
senses or reacts to incoming stimuli.
BENZODIAZEPINES USED AS ANXIOLYTICS
Benzodiazepines
, the most frequently used anxiolytic
drugs, prevent anxiety without causing much associ-
ated sedation. In addition, they are less likely to cause
physical dependence than many of the older sedatives/
hypnotics that are used to relieve anxiety. Table 20.1
lists the available benzodiazepines, including common
indications and specific information about each drug.
TABLE 20.1
DRUGS IN FOCUS Benzodiazepines* used as anxiolytics
Drug name
Dosage/route
Usual indications
alprazolam (Xanax)
1.5–4.5 mg/day PO
Anxiety; panic attack
Onset:
30 minutes
Duration:
4–6 hours
Special considerations:
Taper after long-term
therapy
bromazepam (Lexotan)
Adult: 3–12 mg PO t.d.s.
Anxiety, agitation
Onset:
0.5–4 hours
Duration:
12–24 hours
clobazam (Frisium)
Adult: 10–30 mg PO daily in single or
divided dose
Acute anxiety, sleep disturbance
Onset:
1–4 hours
Duration:
17–49 hours
diazepam (Valium)
Adult: 2–10 mg PO b.d. or t.d.s.
Paediatric (6 months–3 years):
1–6 mg/day
Paediatric (4–14 years): 4–12 mg/day
Anxiety; alcohol withdrawal; muscle relaxant;
antiepileptic; antitetanus; preoperative anxiolytic
Onset:
5–60 minutes
Duration:
3 hours
Special considerations:
Monitor injection sites;
drug of choice if route change is anticipated;
taper after long-term therapy
lorazepam (Ativan)
1–10 mg/day PO in divided doses; or
0.05 mg/kg IM; or 0.044 mg/kg IV
Anxiety; preanaesthesia anxiolytic
Onset:
1–30 minutes
Duration:
12–24 hours
Special considerations:
Monitor injection sites;
reduce dosage of narcotics given with this drug
oxazepam (Serepax)
10–15 mg PO t.d.s. to q.i.d.
Anxiety; alcohol withdrawal
Onset:
slow
Duration:
2–4 hours
Special considerations:
Preferred for elderly
temazepam (Normison)
10–30 mg PO at bedtime
Hypnotic; treatment of insomnia
Onset:
varies
Duration:
4–6 hours
Special considerations:
Taper after long-term
therapy
triazolam (Halcion)
0.125–0.5 mg PO at bedtime
Hypnotic; treatment of insomnia
Onset:
varies
Duration:
2–4 hours
Special considerations:
Monitor liver and renal
function, FBC; taper after long-term therapy
*Onset of action and duration are important in selecting the correct drug for a particular use.
