This document provides information on various types of anti-depressant medications including tricyclics, tetracyclics, SSRIs, SNRIs, MAOIs and other options. It discusses factors that influence medication choice such as features of illness, suicide risk, side effects and cost. Common reasons for drug failure and specific medications are outlined along with dosing information and considerations for treating anxiety.

1. Anti-depressants
Or What When
Dr Bruce Davies
www.bradfordvts.co.uk

2. Range
 Tricyclics
 Tetracyclics
 SSRI
 SNRI
 MAOI
 Oddities
 Adjuvants

3. 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

4. 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.

5. 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

6. 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

7. Tricyclics
Lofepramine
 Least toxic TCA.
 Minimal sedative
side effects.
 Anticholinergic +
 Doubts about
efficacy.
 210 mg / day
Protriptyline
 Stimulant.
 Anticholinergic +
 40mg / day

8. 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

9. 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.
?

10. 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

11. 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.

12. 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.

13. Oddities
Trazodone.
 Unique structure.
 Low cardiotoxicity, few
anticholinergic side effects.
 Drowsiness +.
 Nausea.
 150 mg /day.

14. 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

15. Adjuvants and Combinations
 Realm of
specialists
 Lithium,
carbamazepine
 Mixtures i.e. SSRI
and TCA
 Dangerous – need
expert supervision

16. 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.

17. Anxiety
 ? Role of
benzodiazepines.
 ? Beta-blockers.
Buspirone.
 Some efficacy, but
small.
 Slow onset, 2-4
weeks.

18. DSM - IV
Duration > 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

19. Incidence Of Depression:
2000 Patients
100 - major
100 - minor
200 -
subclinical
Depression. In 50% of patients it
may not be acknowledged.

20. ICD - 10
Patient 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?

21. 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.

22. 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.

23. 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.