1. Drugs in Psychiatry
Antipsychotics (Neuroleptics)
Prescribing:
“I wouldreviewthe needforthismedication:”
- Do theyneedanantipsychotic?
- Do theyneeda differentantipsychotic?
- Do theyneedthisdose?
PrescribingBZD:“…butI wouldfollowupfor 2-4 weekstopreventriskof dependence.”
Acute Dystonia- Groups of m. spasms.(e.g.oculogyric–eyesroll over, neckpulledovertoone side.)
Tardive Dyskinaesia – Incurable sloworbelatedonsetinvoluntarymovementdisorder –Orofacial – lipsmacking.Oppositeof Parkinson’sdisease.
Agranulocytosis –Acute neutropeniacausingimmune suppression.MustmonitorWCC
Before:
o Check FBC
o Register Dr, Pt, Pharmacistwith drug Co.’s monitoringservice
Subsequently:
o Weekly FBC for 18wks
o Fortnightly FBC for rest of year
o Monthly FBC thereafter.
Procyclidine– Antimuscarinictreatmentof EPSE:usedto balance ACh(excitatory)inresponseto↓dopamine(inhibitory)
2. Typical Antipsychotics (1st
Gen) Advantagesof Atypicals:
Cheap
Experience with use and SE
Emergency – when oral route will taketoo long, can
be injected when pt acutely disturbed.
Injected as a depot long term Tx. ↑ compliance.
(e.g. Flulpenthixol)
NAME OF MEDICATION Phenothiazines
Chlorpromazine
Trifluroperazine
Butropenones
Haloperidol
Droperidol
Thioxanthenes
Flupenthixol
Zuclopenthioxol
INDICATION Shizophrenia
Mania
Dopamine SE:
HyposthalamicPitutiaryAxis:
↑prolactin levels galactorrhoea,impotence.
EPSE (Nigrostriatal):
Acute dystonia – anticholinergic
Parkinsonism–anticholinergic, (NOT L-dopa)
Akathesia – β-blocker, BZD, anticholinergic
Tardivedyskinaesia
AnticholinergicSE:
Constipation
Blurred vision
Dry Mouth
Confusion
Histamine SE:
Sedation
α1 – SE:
Postural HoTN
Impotence
Other SE:
Neuroleptic malignantsyndrome(rare, high
mortality 30-50%)
Weight Gain
Arrhythmia
↓seizure threshold
MECHANISMOF ACTION D2 receptorantagonism
(non-selective)
DOSE 0.5-3mg BD
Up to 30mg (resistant
schizophrenia)
Adjustdose forlowest
maintenance.
SIDE-EFFECTS EPSE EPSE EPSE
CAUTIONS
INTERACTIONS Amiodarone– CVS
tachyarrythmias,QTinterval.
ACEi & CCB – Enhanced
hypotensive effect
CONTRAINDICATIONS
3. Atypical Antipsychotics(2nd
Gen.) Advantagesof Atypicals:
DifferentSEprofile (less
likelytocause EPSE- ↓risk
of tardive dyskinesia.
As effective astypicals.
Disadvantages
Expensive (notpreferentially
used1st
line)
Many onlyavailable asoral
except:
o Olanzapine IM
o RisperidoneIM$$
COMMON SE OF ATYPICALS
EPSE at highdose
Sedation
Weightgain,DM,
Cholesterol.
↓seizure threshold
METABOLIC SYNDROME
GENERAL CAUTIONSATYPICALS
CVSdisease - ECG
Parkinson’sDisease–
exacerbatedwith
antipsychotics
Photosensitisation –Avoid
sunlight.
NAME OF
MEDICATION
Clozapine Olanzapine Amisulpiride Risperidone Quetiapin
e
Aripiprazole
(Abilify)
INDICATION Onlydrug effective in
resistantSchizophrenia
If pt has not improved
after2 trailsof meds
then3rd
optionshould
alwaysbe Clozapine
Schizophrenia Acute
psychosis
Mania
Psychosis
Bipolar
MECHANISMOF
ACTION
D1, D2, 5-HT & α1 D1, D2, 5-HT, H1
antagonist
D2, D3
antagonist
D2, 5-HT, α1
antagonist
DOSE 12.5mg once
25-50mg on 2nd
day
Increase gradually
25mg intervalsif
well toleratedto
300mg
2mg day 1
4mg day 2
Maintenance
dose 4-6mg
SIDE-EFFECTS Sedation
Anticholinergic
Weightgain
↓↓seizure threshold
Hypersalivation
AGRANULOCYTOSIS
Constipation
Dry mouth
N+V
CAUTIONS
INTERACTIONS Diazepam– synergistic
Marrow suppressants -
increasedriskof BM
dysfunction
Citalopram
- ProlongedQTinterval
- Ventriculararrhythmia
CONTRAINDICATIONS CVSdisorders
- Myocarditis
- Prolongedtachycardia
Neutropenia
Coma/CNSdepression
Acute alcohol intoxication
- CNSdepression
- Avoidindrinkers.
Must monitor WCC
Before:
- Check FBC
- Register Dr, Pt, Pharmacistwith
drug Co.’s monitoringservice
Subsequently:
- Weekly FBC for 18wks
- Fortnightly FBC for rest of year
- Monthly FBC thereafter.
4. Antidepressants TCA SSRI SNRI NARI
NAME OF MEDICATION Amitryptilline
Imipramine
Dosulepin
Lofepramine
Fluoxetine(Prozac)
Citalopram
Paroxetine(Seroxat)
Sertraline (Lustral)
Venlafaxine Raboxetine
INDICATION Depressive illness
Migraine prophylaxis
Helpful inresistant
disease where SSRIfail.
Rarelyused
MECHANISM OF ACTION Inhibitreuptake of 5-HT& NA Selectiveserotoninreuptake
inhibition.
Serotonin+
Noradrenalinereuptake
inhibitor.
NA reuptake
inhibitor.
DOSE
SIDE-EFFECTS Anticholinergic
- Dry mouth
- Constipation
- Blurredvision
Histamine
- Sedation
α1
- Postural HoTN
- Impotence
Quinidinelike
- ECG changes
- Arrhythmia
5-HT
- GI upset,sweating
NA
- TREMOR
GI – Nausea, Diarrhoea
Sweating
Insomnia/agitation/akathesia
Sexual dysfunction
↓seizure threshold(inep.)
Discontinuationsyndrome
Generallywelltolerated.
SimilartoSSRI,
Can getdiscontinuation
syndrome:“Brainzaps”
Interferencewithnormal
social function
Nausea
Insomnia
Tremor
CAUTIONS DANGEROUS IN OD
DANGEROUS IN CVSDISEASE
INTERACTIONS
CONTRAINDICATIONS
TCA withdrawal symptoms:
↑anxiety
Sleepdisturbance
Psychoticfeatures
Cautionabruptwithdrawal
seizures,coma&death.
5. α2 ReceptorAntagonist MAOI ECT Psychosurgery
NAME OF
MEDICATION
Mirtazipine
Mianserin
Isocarboxazid
RIMA moclobemide
Phenelzine
Tranylcypromine
Depression (if severe orresistant)
Mania(infrequently)
Schizophrenia (rarely)
Indications:
Intractable depression
OCD
Techniques:
Cingulotomy
Subcaudate
tractotomy
Section57 MHA (2nd
opinion+consent)
INDICATION α2 receptorantagonist
(some postsynaptic5HT
action)
Rarelyused unlesspartof
combinationtherapy - not
veryeffective
Anaesthetic+ muscle relaxant
Brief pulse of electricity
Modifiedgrandmal fit(15-60s)
Bilateral
Electrode oneachtemple
More effectivethan unilateral andeasierto
administer
↑memoryimpairment
Unilateral
One electrode onRtemple one onback of
head.
Technicallydifficult&lesseffective
↓memoryimpairment
LEGALITY :
Informal Pt. – Informedconsent
DetainedPt.
Either informedconsent
Or 2nd
opinionfromMHA commissionedDr.(SOAD)
Emergency – can give 1-2 Tx while waitigforSOAD
SIDE EFFECTS:
Mortality1/22,000
Headache
MemoryImpairment.
STM esp.autobiographical
No evidenceforpermanentdmg.
MECHANISMOF
ACTION
Preventbreakdown of:
Serotonin
Melationin
Adrenaline
Noradrenaline
Dopamine
Tyramine
DOSE
SIDE-EFFECTS Sedation&weightgain
MianserinCan cause
blooddyscrasias
Cheese rxn HTN crisis
stroke death.
CAUTIONS
INTERACTIONS TCA (2wksposst)
Cheese rxn HTN crisis
stroke death.
CONTRAINDICATIONS CVSdisease
Pheochromocytoma
Elderly