McKenna's Pharmacology for Nursing, 2e

326

P A R T 4  Drugs acting on the central and peripheral nervous systems

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 Treatment of major depressive disorder and management of neuropathic pain associated with diabetic peripheral neuropathy Treatment of major depressive disorder, maintenance of people with major depressive disorder and generalised anxiety disorder 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 Treatment of OCDs; also under investigation for treatment of depression, bulimia, panic disorder and social phobia 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 Treatment of depression, OCDs, social anxiety disorder, posttraumatic stress disorder, panic disorders and PMDD

duloxetine (Cymbalta)

30 mg/day PO, up to 120 mg/day if needed

escitalopram (Lexapro)

10 mg/day PO as a single dose; 10–20 mg/day PO maintenance

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

fluoxetine (Prozac, Sarafem, Lovan)

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 10–20 mg/day PO; do not exceed 50 mg/day; reduce dose in hepatic or renal dysfunction and with the elderly

paroxetine (Aropax)

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

( Luvox ); paroxetine ( Aropax ); and sertraline ( Xydep , Zoloft ).

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

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