Anti-depressants

Or What When

Dr Bruce Davies

Range

Tricyclics Tetracyclics SSRI SNRI MAOI Oddities Adjuvants

Factors Influencing Choice Features of illness, e.g.

agitation, hypersomia Suicide risk Other therapy Other illness. Side effects Cost Special problems e.g.

Age, driving, pregnancy

Drug Failure

Non compliance. Inadequate dosage. Other drugs e.g. alcohol, caffeine. Unresolved outside problems. Up to 25% failure even if above don’t

apply.

Tricyclics

Amitryptyline Potent sedative Weight gain ++ Anticholinergic ++ Most researched 150mg / day

(Therapeutic in 95% of adults)

Clomipramine Similar side effects to

amitryptyline. Said to be best for

obsessional symptoms. 150mg / day

Tricyclics

Dothiepin Sedative Same side effects as

amitryptyline. By far and away the

most toxic antidepressant.

150 mg / day

Imipramine Stimulant Anticholinergic ++ 150 mg/ day

Tricyclics

Lofepramine Least toxic TCA. Minimal sedative side

effects. Anticholinergic + Doubts about efficacy. 210 mg / day

Protriptyline Stimulant. Anticholinergic + 40mg / day

Tetracyclics

Maprotiline Similar side effect

profile to amitryptyline.

Seizures severe in overdose.

150 mg /day

Mianserin Good safety in

overdose. Few sedative or

anticholinergic properties.

? Agranulocytosis risk 90 mg / day

SSRI

First choice in elderly. First choice if heart

disease. First choice if suicide

risk. More expensive.

Side effects Like TCA reduce with

time. Gut problems

predominate. Flat dose response

curve – so no need to titrate dose upwards.

?

SSRI

Citalopram Few interactions

Most expensive

20 mg /day

Fluoxetine Sedation –

Skin s/e

Anxiety +

Cheapest

20-80 mg /day

Fluvoxamine Gut s/e + Insomnia - 200 mg /day

Paroxetine Sedation + Withdrawal problems ?

20 mg /day

Sertraline Diarrhoea 50 mg /day

SSNRI

Venlafaxine Selective Serotonin and noradrenaline

reuptake inhibitor – like amitryptyline. Few other effects – unlike amitryptyline. 75-150mg / day minimum Dry mouth, somnolence, high BP, nausea,

headache and dizziness.

MAOI

The old ones block peripheral MAOI ( B ) and central MAOI (A) so a low tyramine diet is needed. ? Obsolete.

Moclobemide. Only MAOI-A. ? Role. ? Special place in anxiety disorder. 300-600mg / day.

Oddities

Trazodone. Unique structure. Low cardiotoxicity, few anticholinergic

side effects. Drowsiness +. Nausea. 150 mg /day.

Oddities

Tryptophan Natural amino acid - Serotonin precursor. Eosinophilia-myalgia syndrome, Hospital

initiation only. Adjuvant to others ?Flupenthixol Some doubts as to efficacy. Fast action 1 mg / day

Adjuvants and Combinations

Realm of specialists Lithium,

carbamazepine Mixtures i.e. SSRI and

TCA Dangerous – need

expert supervision

Anxiety Usually worth trying a

antidepressant. May be useful to avoid the

stimulant ones ! May need higher doses. Initiation may lead to

paradoxical increase in symptoms. ? Cover with short course of anxiolytic.

Anxiety

? Role of benzodiazepines.

? Beta-blockers.

Buspirone. Some efficacy, but

small. Slow onset, 2-4 weeks.

DSM - IVDuration > 2 weeks

Depressed mood or Marked loss of interest or pleasure in normal activities

Plus 4 of:

i. Significant change in weight

ii. Significant change in sleep pattern

iii. Agitation or retardation

iv. Fatigue or loss of energy

v. Guilt / worthlessness

vi. Can’t concentrate or make decisions

vii. Thoughts of death or suicide

Incidence Of Depression : 2000 Patients

100 - major

100 - minor

200 - subclinical

Depression. In 50% of patients it may not be acknowledged.

ICD - 10Patient has low mood:

1) How bad is it and how long has it been going on?

2) Have you lost interest in things?

3) Are you more tired than usual?

If the answer is yes to these, then:

4) Have you lost confidence in yourself?

5) Do you feel guilty about things?

6) Concentration difficulties?

7) Sleeping problems?

8) Change in appetite or weight?

9) Do you feel that life is not worth living any more?

ICD - 10

Mild

Two criteria from 1-3 and 2 others. Moderate

Two criteria from 1-3 and 3-4 others or a yes to question 5.

Severe

Most of the criteria in severe form especially questions 5 & 9.

BUT BUT BUT

But there is a lot more than the drugs.

The use of other therapies is equally important.

The doctor may be the best drug.

Availability is often the limit to other treatment methods.

Based On

BNF June 2000. Depression in General Practice. Tylee,

Priest & Roberts. Pub. Martin Dunitz. 1996. GP Psychotropic Handbook. S Bazire.

Quay Books. 1995. Basic Notes in Psychiatry. Michael Levi.

Kluwer Books. 1997.