1. Psychopharmacology in Psychiatry
By : Dr Seddigh
HUMS

2. Classification of antidepressants
Tricyclics (TCAs)
Monoamine Oxidase Inhibitors (MAOIs)
Selective Serotonin Reuptake Inhibitors (SSRIs)
Serotonin/Norepinephrine Reuptake Inhibitors (SNRIs)
Novel antidepressants

3. Cyclic Antidepressants
Drug Trade name Daily dosage
Amitriptyline Elavil* mg
Clomipramine Anafranil mg
Imipramine Tofranil* mg
Nortriptyline Aventyl* mg
Pt taking amitriptyline (Elavil) has to be watched for orthostatic hypotension, arrhythmias, and eye pain

4. Common Side effects of TCAs
Mechanism
Complication
overdose

5. Drug Interactions with Cyclic Antidepressants
Alcohol
Antiparkinsonians
Antipsychotics
Fluoxetine(Prozac)
Phenobarbitol
Sedatives

6. Antidepressants
Indications

7. TCAs
effective & unacceptable
Lethal in overdose
QT lengthening

8. Selective Serotonin Reuptake Inhibitors (SSRIs)
Presynaptic reuptake
Anxiety or depressive sx
Side effects
Overdose
Discontinuation syndrome

9. The SSRI antidepressant
Drug Trade name Daily dosage/starting
Fluoxetine Prozac mg/20 mg
Paroxetine Paxil mg/ 20 mg
Sertraline Zoloft mg/50 mg
A Common side effect of SSRI that pt may be reluctant to report is sexual dysfunction

10. Paroxetine (Paxil) half life & metabolite Sedating CYP2D6 inhibition
Complication
discontinuation syndrome

11. Sertraline (Zoloft) interactions Short half Less sedating absorption
GI adverse

12. Fluoxetine (Prozac) Long half-life Initially activating taper someone
hepatic illness
interactions
increase anxiety and insomnia
induce mania

13. Antidepressants - MAO Inhibitors Isocarboxazid Marplan 45-90 mg
Drug Trade name Daily dose
Isocarboxazid Marplan mg
Phenylzine Nardil mg
Tranylcypromine Parnate mg
Pt taking Parnate, a MAOI should avoid foods containing tyramine ie cheese, red wine, avocado
MAOI -> hypotension For elderly, Nardil is the most commonly prescribed one for the elderly

14. Foods & Drugs to be avoided
Aged cheeses Amphetamine
Beer Cocaine
Broad-bean pods Decongestants
Caffeined beverages Epinephrine
Canned figs L-dopa
Other Foods to be avoided – Chocolate, Non-fresh, fermented, or preserved fish, liver, and meats Red wine, Yeast extracts, Yogurt & sour cream, Avocado.
tyramine (amino acid) is the culprit

15. Overview of antidepressants
1st choice
weeks effective → TCAs
Abrupt withdrawal TCAs
MAOIs “tyramine”
TCAs to MAOIs

16. Monoamine Oxidase Inhibitors (MAOIs)
Bind to monoamine oxidase
effective
Side effects
Hypertensive crisis

17. MAOIs cont.
Serotonin Syndrome
Wait 2 weeks
Fluoxetine

18. Overview of antidepressants
1st choice
weeks effective → TCAs
Abrupt withdrawal TCAs
MAOIs “tyramine”
TCAs to MAOIs

19. Serotonin/Norepinephrine reuptake inhibitors (SNRIs)
v/s TCAS
Indication

20. Venlafaxine (Effexor)
interactions
geriatric
diastolic BP.
nausea
discontinuation
QT prolongation
Sexual side

21. Duloxetine (Cymbalta)
depression

22. Novel antidepressants Mirtazapine (Remeron)
Pros
Different mechanism of action may provide a good augmentation strategy to SSRIs. Is a 5HT2 and 5HT3 receptor antagonist
Can be utilized as a hypnotic at lower doses secondary to antihistaminic effects
Cons
Increases serum cholesterol by 20% in 15% of patients and triglycerides in 6% of patients
Very sedating at lower doses. At doses 30mg and above it can become activating and require change of administration time to the morning.
Associated with weight gain (particularly at doses below 45mg

23. Buproprion (Wellbutrin)
Pros
Good for use as an augmenting agent
Mechanism of action likely reuptake inhibition of dopamine and norepinephrine
No weight gain, sexual side effects, sedation or cardiac interactions
Low induction of mania
Is a second line ADHD agent so consider if patient has a co-occurring diagnosis
Cons
May increase seizure risk at high doses (450mg+) and should avoid in patients with Traumatic Brain Injury, bulimia and anorexia.
Does not treat anxiety unlike many other antidepressants and can actually cause anxiety, agitation and insomnia
Has abuse potential because can induce psychotic sx at high doses

24. Overview of antidepressants
1st choice
weeks effective → TCAs
Abrupt withdrawal TCAs
MAOIs “tyramine”
TCAs to MAOIs

25. Anxiolytics
Used to treat many diagnoses including panic disorder, generalized Anxiety disorder, substance-related disorders and their withdrawal, insomnias and parasomnias. In anxiety disorders often use anxiolytics in combination with SSRIS or SNRIs for treatment.

26. Benzodiazapines
Used to treat insomnia, parasomnias and anxiety disorders.
Often used for CNS depressant withdrawal protocols ex. ETOH withdrawal.
Side effects/cons
Somnolence
Cognitive deficits
Amnesia
Disinhibition
Tolerance
Dependence

27. Peak Blood Level (hours) Elimination Half- Life1 (hours)
Drug
Dose Equivalency (mg)
Peak Blood Level (hours)
Elimination Half- Life1 (hours)
Comments
Alprazolam (Xanax)
0.5
1-2
12-15
Rapid oral absorption
Chlordiazepoxide (Librium)
10.0
2-4
15-40
Active metabolites; erratic bioavailability from IM injection
Clonazepam (Klonopin)
0.25
1-4
18-50
Can have layering effect
Diazepam (Valium)
5.0
20-80
Flurazepam (Dalmane)
30.0
40-100
Active metabolites with long half-lives
Lorazepam (Ativan)
1.0
1-6
10-20
No active metabolites
Oxazepam (Serax)
15.0
Temazepam (Restoril)
2-3
10-40
Slow oral absorption
Triazolam (Halcion) 1
Rapid onset; short duration of action

28. Buspirone (Buspar) Pros: Cons:
Good augmentation strategy- Mechanism of action is 5HT1A agonist. It works independent of endogenous release of serotonin.
No sedation
Cons:
Takes around 2 weeks before patients notice results.
Will not reduce anxiety in patients that are used to taking BZDs because there is no sedation effect to “take the edge off.