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C H A P T E R 2 2 Psychotherapeutic agents

Cortex

■■ Lithium, a membrane stabiliser, is the standard antimanic drug. Because it is a very toxic salt, serum levels must be carefully monitored to prevent severe toxicity. ■■ Many other CNS drugs, including many of the atypical antipsychotics, are now approved for use in bipolar disorder. Many people respond to a combination of these drugs to control their bipolar signs and symptoms. CENTRAL NERVOUS SYSTEM STIMULANTS CNS stimulants are used clinically to treat both atten- tion deficit disorders and narcolepsy. Paradoxically, these drugs calm hyperkinetic children and help them to focus on one activity for a longer period. They also redirect and excite the arousal stimuli from the RAS (Figure 22.2; see also Figure 22.1). The CNS stimulants ■ ■ Monitor for adverse effects (CV toxicity, renal toxicity, GI upset, respiratory complications). ■ ■ Evaluate effectiveness of the teaching plan (person can give the drug name and dosage and describe the possible adverse effects to watch for, specific measures to help avoid adverse effects, warning signs to report and the need to avoid pregnancy). ■ ■ Monitor effectiveness of comfort measures and compliance with the regimen. KEY POINTS

Diffuse thalamo- cortical projections

Thalamus

CNS stimulants work here

Ascending projectional system

Brainstem reticular formation (RAS)

FIGURE 22.2  Site of action of the central nervous system (CNS) stimulants in the reticular activating system (RAS).

that are used to treat attention-deficit disorder and nar- colepsy include methylphenidate ( Ritalin , Concerta and others); dexamphetamine (generic); modafinil ( Modav- igil ), which is not associated with many of the systemic stimulatory effects of some of the other CNS stimulants; as well as the newer drug—atomoxetine ( Strattera ) which is a selective noradrenaline reuptake inhibitor with anticholinergic effects but without the CV and stimulatory effects, making it preferable in people who cannot tolerate the systemic stimulatory effects (see Table 22.3).

TABLE 22.3

DRUGS IN FOCUS Central nervous systems stimulants

Drug name

Dosage/route

Usual indications

atomoxetine (Strattera)

Adults and children >70 kg: 40 mg/day PO, slowly increase to a target daily dose of 80 mg Children ≤70 kg: 0.5 mg/kg per day, increase to a target daily dose of 1.2 mg/kg per day Hepatic impairment: decrease dose by 50% Narcolepsy: 5–60 mg/day PO in divided doses Attention-deficit disorders: 2.5–5 mg/day PO taken in the morning Adult: 10–60 mg/day PO in divided doses, depending on preparation Paediatric: 5 mg PO b.d.; increase gradually, do not exceed 60 mg/day

Treatment of attention-deficit/hyperactivity disorders as part of a total treatment program

dexamphetamine (generic)

Treatment of narcolepsy, attention-deficit disorders, behavioural syndromes

Treatment of attention-deficit disorders and other behavioural syndromes associated with hyperactivity, as well as narcolepsy; currently available in various forms allowing for dosing one, two or three times a day Treatment of narcolepsy in adults, for improving wakefulness in various sleep disorders and for improving wakefulness in people with obstructive sleep apnoea/ hypopnoea syndrome

methylphenidate (Ritalin, Concerta

and others)

modafinil (Modavigil)

200 mg/day PO as a single dose; reduce dose with hepatic impairment and in the elderly