Drugs used in the treatment of affective disorders Dr. Vidumini De Silva

Disorders of the mood Depression Mania Manic depressive psychosis

Depression and anti depressanats monoamine hypothesis endogenous depression is due to deficiency of CNS noradrenergic or serotonergic activity or transmission drugs used in depression elevates the level of these

Antidepressanats Tricyclic antidepressants Monoamine oxidase inhibitors(MAO) Selective serotonin reuptake inhibitors(SSRI) SSNRI

Tricyclic antidepressanats Inhibit the reuptake of noradrenaline and 5 hydroxytryptamine in brain. Take a week or more to show there antidepressant effect Have anticholinergic and anti histaminic effects. Best given one daily oral dose at night treatment is usually started with a small dose at night and increased at 2 weekly intervals.

Indications for use Depression Neuralgias Nocturnal enuresis in children Irritable bowel syndrome Some forms of headache

Adverse effects Dry mouth,blurring of vision,constipation and difficulty in micturition CVS effects tachycardia. Arhythmias May precipitate epilepsy confusion in the elderly

Monoamine oxidase inhibitors MAO is one of the two main enzymes involved in the metabolism of 5HT and catecholamines in depression not responding to other medication

SSRI’s Less side effects compared to Tricyclics and MAO inhibitors specially anticholinergic effects Doesn’t offer greater efficacy than TCA in depression eg Fluoxetine, Fluvoxamine, Paroxetine, Citalopram, Sertraline

SSRI Used in Depression, Panic disorders, Bulimia nervosa, Obsessive compulsive disorder and social phobias. Venlafaxine is a SSNRI used in depression and anxiety disorder

Side Effects Gastrointestinal side effects are common Nausea Vomiting Diarrhoea Constipation Abdominal pain

Venlafaxine SSNRI Less sedating Less anticholinergic effects Should be used with caution in IHD and hypertension

Drugs used in manic depressive psychoses Lithium Carbamazepine Sodium valproate

Lithium Effective in the prophylaxis of manic depressive psychoses,unipolar depression and treatment of acute mania Well absorbed from the gut and eliminated unchanged in urine Has a narrow therapeutic index. Needs the monitoring of plasma concentrations. Toxicity is common if levels >1.5mmol/l CNS side effects like tremor,giddiness and ataxia may be the early features of toxicity.

Carbamazepine Used in the prophylaxis of manic depressive psychoses Used In patients who cannot tolerate lithium or who do not respond to lithium