6. Drugs used in Mania – MoodDrugs used in Mania – Mood
StabilizersStabilizers
Lithium CarbonateLithium Carbonate
Alternative Drugs:Alternative Drugs:
– CarbamazepineCarbamazepine
– Sodium ValproateSodium Valproate
– LamotrigineLamotrigine
– TopiramateTopiramate
– Atypical anyipsychotics – Olanzapine, risperidoneAtypical anyipsychotics – Olanzapine, risperidone
7. Lithium Carbonate – PharmacologicalLithium Carbonate – Pharmacological
actionsactions
CNS:CNS:
– No discernible psychotropic effect in normalNo discernible psychotropic effect in normal
individualsindividuals
– Similarly, no effect on Manic-depressiveSimilarly, no effect on Manic-depressive
patientspatients
– On prolonged administration – acts as moodOn prolonged administration – acts as mood
stabilizerstabilizer
– Suppresses the episodes af attackSuppresses the episodes af attack
9. Lithium Carbonate – Mechanism ofLithium Carbonate – Mechanism of
actionaction
1.1. Effect on Electrolyte and ion transport:Effect on Electrolyte and ion transport:
– Li is the lightest of the alkali metal atomsLi is the lightest of the alkali metal atoms
– Na+ and K+ are important in this familyNa+ and K+ are important in this family
– Li distributes evenly in extracellular and intracellular fluidsLi distributes evenly in extracellular and intracellular fluids
(contrast to Na+ and K+)(contrast to Na+ and K+)
– Build up a small concentration gradient across cellBuild up a small concentration gradient across cell
membranemembrane
– But, cannot be transported via Na+/K+ ATPaseBut, cannot be transported via Na+/K+ ATPase
– Interfere with transuducer mechanism of cell membraneInterfere with transuducer mechanism of cell membrane
10. Lithium Carbonate – MechanismLithium Carbonate – Mechanism
of actionof action
2.2. Effects on 2Effects on 2ndnd
MessengerMessenger
– IPIP33 and DAG are important 2and DAG are important 2ndnd
messenger for alpha andmessenger for alpha and
Muscarinic transmissionMuscarinic transmission
– Lithium inhibits several enzymes in the normal recycling ofLithium inhibits several enzymes in the normal recycling of
PhosphoinositidePhosphoinositide
– These include IPThese include IP22 to IPto IP11 and IP to Inositoland IP to Inositol
– These leads to depletion of PIPThese leads to depletion of PIP22, the membrane precursor, the membrane precursor
of IPof IP33 and DAGand DAG
– Ultimate effect may be in G-protein receptors – mayUltimate effect may be in G-protein receptors – may
uncouple receptors from G-proteinuncouple receptors from G-protein
12. Lithium Carbonate, Mechanism –Lithium Carbonate, Mechanism –
contd.contd.
3.3. Neurotransmitters:Neurotransmitters:
– Enhances the action of SerotoninEnhances the action of Serotonin
– Decrease the noradrenaline and dopamineDecrease the noradrenaline and dopamine
turnover – antimanic actionturnover – antimanic action
– Augment synthesis of AcetylcholineAugment synthesis of Acetylcholine
13. Lithium Carbonate - PharmacokineticsLithium Carbonate - Pharmacokinetics
•Initial Dose is 600 mg/day and gradually increased (600 to
1200 mg/day
Well absorbed orally, but slowlyWell absorbed orally, but slowly
Not metabolized and not protein boundNot metabolized and not protein bound
Attains uniform distribution in total bodyAttains uniform distribution in total body
waterwater
Apparent Vd – 0.8L/kg at steady stateApparent Vd – 0.8L/kg at steady state
14. Lithium, Pharmacokinetics –Lithium, Pharmacokinetics –
contd.contd.
Li is actively reabsorbed from proximal tubule in theLi is actively reabsorbed from proximal tubule in the
kidney similar to Na+kidney similar to Na+
When Na+ is restricted larger portion of Na+ isWhen Na+ is restricted larger portion of Na+ is
reabsorbed - similar is in case of Lireabsorbed - similar is in case of Li
Initially rapid excretion, then slower in later phase.Initially rapid excretion, then slower in later phase.
T1/2 is 16 to 30 HrsT1/2 is 16 to 30 Hrs
Clearance is 20% of creatinineClearance is 20% of creatinine
Steady state is attained in 5-7 daysSteady state is attained in 5-7 days
Available as 300 and 400 mg tabletsAvailable as 300 and 400 mg tablets
15. Lithium – Monitoring of TreatmentLithium – Monitoring of Treatment
Individual variation in the rate of excretionIndividual variation in the rate of excretion
Narrow margin of safetyNarrow margin of safety
Done 5 days after the start of treatmentDone 5 days after the start of treatment
Measurement is done 12 Hrs after the last doseMeasurement is done 12 Hrs after the last dose
If no therapeutic improvement, chnge the doseIf no therapeutic improvement, chnge the dose
New dose = desired plasma level/present levelNew dose = desired plasma level/present level
Monitor the new dose level after 5 days againMonitor the new dose level after 5 days again
If steady state (0.5 to 0.8 mEq/L – increase theIf steady state (0.5 to 0.8 mEq/L – increase the
interval of monitoringinterval of monitoring
16. Lithium – Adverse EffectsLithium – Adverse Effects
1.1. CNS:CNS:
– Tremor is frequentTremor is frequent
– Coarse tremor, giddiness, ataxia, motor incoordination,Coarse tremor, giddiness, ataxia, motor incoordination,
nystagmus etc. – delirium, comanystagmus etc. – delirium, coma
– Occurs mainly when plasma level is high (2mEq/L)Occurs mainly when plasma level is high (2mEq/L)
– Treat with propranolol, atenolol etc.Treat with propranolol, atenolol etc.
– If required – Osmotic diuretics for Li excretionIf required – Osmotic diuretics for Li excretion
1.1. Renal: Polyuria and PolydipsiaRenal: Polyuria and Polydipsia
– Loss of ability of collecting tubules to conserve water by influenceLoss of ability of collecting tubules to conserve water by influence
of ADH (G protein)of ADH (G protein)
– Excessive free water clearanceExcessive free water clearance
– Nephrogenic Diabetes InsipidusNephrogenic Diabetes Insipidus
17. Lithium, Adverse Effects – contd.Lithium, Adverse Effects – contd.
3.3. Cardiac Effects:Cardiac Effects: Sick-sinus syndrome –Sick-sinus syndrome –
contraindicated – flattening of T wavecontraindicated – flattening of T wave
4.4. Thyroid Function:Thyroid Function: Decrease in thyroidDecrease in thyroid
Function – goitre (G protein)Function – goitre (G protein)
5.5. PregnancyPregnancy – contraindicated– contraindicated
– Foetal goitre, congenital abnormalities (cardiac)Foetal goitre, congenital abnormalities (cardiac)
18. Lithium – Drug InteractionsLithium – Drug Interactions
Diuretics: Renal clearance of Lithium is reduced byDiuretics: Renal clearance of Lithium is reduced by
25% with Diuretic e.g. furosemide, Thiazides25% with Diuretic e.g. furosemide, Thiazides
NSAIDS: Renal clearance of Lithium is reduced byNSAIDS: Renal clearance of Lithium is reduced by
25%25%
All Neuroleptics, except clozapine – increased EPSAll Neuroleptics, except clozapine – increased EPS
Insulin and oral hypoglycaemics: enhanceInsulin and oral hypoglycaemics: enhance
hypoglycaemiahypoglycaemia
19. Antimanic – Other Drugs
Carbamazepine:
– Prolong remission
– Relapse with Li+ therapy and rapid cycling of
Mood – Li + CBZ
Sodium Valproate:
– Ist line in acute mania
– Lithium resistance cases
– Lithium + Valproate – resistance to monotherapy
20. Antimanic Drugs - contd.
Lamotrigine:
– Not for acute cases but Bipolar disorders
– Used as monotherapy as well as with Lithium
Atypical antipsychotics:
– 1st line in acute mania in combination with BZD
except patient requiring parenteral therapy
– Olanzapine in maintenance therapy and
prophylaxis
22. ANTIDEPRESSANTS
1. MAO inhibitors:
– Irreversible: Isocarboxazid, Iproniazid, Phenelzine and
Tranylcypromine
– Reversible: Moclobemide and Clorgyline
1. Tricyclic antidepressants (TCAs)
NA and 5 HT reuptake inhibitors – Imipramine,
Amitryptiline, Doxepin, Dothiepin and Clomipramine
NA reuptake inhibitors – Desimipramine, Nortryptyline,
Amoxapine
1. Selective Serotonin reuptake inhibitors:
– Fluoxetine, Fluvoxamine, Sertraline and Citalopram
1. Atypical antidepressants:
– Trazodone, Mianserin, Mirtazapine, Venlafaxine, Duloxetine,
Bupropion and Tianeptine
23. Causes of Depression and
Mechanism of antidepressants
The Monoamine Theory:
Adrenaline, Noradrenaline, Dopamine and 5-HT
are neurotransmitters (Biogenic amines)
Called Noradrenergic, Serotonergic or
Dopaminergic etc. neurones
Normally NA and 5 HT are in adequate numbers
at post synaptic region
In DEPRESSION – Deficiency of NA or 5 HT or
BOTH
24. Mechanism of antidepressants –
contd.
Drugs act by increasing the local availability of NA or
5 HT
MAO Inhibitors: MAO is a Mitochondrial Enzyme
involved in Oxidative deamination of these amines
MAO-A: Peripheral nerve endings, Intestine and
Placenta (5-HT and NA)
MAO-B: Brain and in Platelets and Mainly
Serotonergic (Phenylalanine)
Selective MAO-A inhibitors (RIMA) have
antidepressant property
25. Mechanism of antidepressants –
contd.
TCAs:
– NA, 5 HT and Dopamine are present in Nerve endings
– Normally, there are reuptake mechanism and termination of
action
– TCAs inhibit reuptake and make more monoamines
available for action
SSRIs:
– Serotonins also reuptaken by Nerve terminals
– SSRIs inhibit the reuptake mechanism and make more 5
HT available for action
27. MAO inhibitors
Drugs: Irreversible: Isocarboxazid, Iproniazid, Phenelzine and
Tranylcypromine, Reversible: Moclobemide and Clorgyline
Not popular now except irreversible selective MAO-A
inhibitors:
– Strict dietary restrictions
– Irreversible action
– Drug-drug interactions
– Safer drugs are available now
Major drawbacks:
– Manic state or hypertensive crisis
– Cheese reactions
– Other drug interactions
28. MAO inhibitors (Drawbacks) – contd.
Drug Interactions:
– Ephedrine (drugs of cold and cough): hypertensive reaction
– Reserpine, guanethidine: excitement and rise in BP
– Levodopa: excitement and rise in BP (delayed degradation
of NA and DA)
– Antiparkinsonian anticholinergics: Hallucinations and
symptoms of atropine poisoning
– MAOI and SSRI: Serotonin Syndrome (Mental confusion,
hallucinations, sweating, hyperthermia, twitching of muscle,
clonus and convulsion)
29. MAO inhibitors – contd.
Moclobomide: Advantages
– Reversible action (1-2 days after stoppage)
– Potentiation of pressor response to dietary
amines is weak
– Dietary restriction not required
– Lack of anticholinergic, sedative,, cognitive and
CVS adverse effects
– Used in elderly patients and with heart diseases
– Mild to moderate depression - alternative to TCAs
30. Tricyclic Antidepressants - Imipramine
NA and 5 HT reuptake inhibitors –
Imipramine, Amitryptiline, Doxepin, Dothiepin and
Clomipramine; NA reuptake inhibitors –
Desimipramine, Nortryptyline, Amoxapine
Analogue of CPZ
Inhibit NET and SERT
Interacts with variety of receptors – alpha, H1,
5HT1, 5HT2 and D2
31. Imipramine – contd.
Early effects – sedation, no other CNS effect
After 2-4 wks:
– Elevation of mood, more communicative
– REM sleep suppressed and no night awakening
– More sedative ones are for agitated and anxiety
patients (amitriptyline, doxepin)
– Withdrawn patients – less sedative Imipramine,
Nortriptyline
– Induce seizure (Clomipramine, bupropion)
32. Imipramine - Mechanism of action
Inhibit uptake of Biogenic amines – NA and 5-HT
No inhibition of DA uptake except Bupropion
Cocaine and amphetamines are inhibitors of DA
uptake – strong CNS stimulant
May facilitate DA transmission in forebrain –
elevation of MOOD
Reuptake inhibition causes – increase amines in
synaptic cleft
Inhibition of DA – stimulant action
Inhibition of NA and 5-HT – antidepressant action
33. Imipramine - Mechanism of action –
contd.
But, antidepressant action starts after few weeks, whereas
blockade starts immediately
Inhibition of uptake is an early step but cascade of events that
follow are important
Initially, auto receptors - α2 and 5-HT1 are activated by excess
of NA/5HT – negative feed back
Limiting of synaptic availability of NA - homeostasis
On repeated exposure – α2 receptor response diminishes -
desensitization of these pre-synaptic receptors
Adaptive changes – in number and sensitivity of pre and
postsynaptic pre-synaptic production and release of NA -
normal or more
No reuptake and no negative feed back
34. Imipramine – Pharmacological actions
ANS: Dry mouth, blurring of vision,
constipation and urinary hesitancy
CVS: Tachycardia –
– NA and anticholinergic action
– Postural hypotension
– ECG – T wave suppression
– Arrhythmia
36. Imipramine - Pharmacokinetics
Good oral absorption but undergo 1st pass effect –
variable bioavailablity
Highly bound to plasma protein and high Vd
Metabolized in Liver: Active metaboites: Imipramine
– desipramine and amitriptyline – nortriptyline
Excreted via urine, t1/2 – 16 to 24 Hrs
One daily dose – because of active metabolites
Therapeutic window phenomenon: Optimal effect at
50-200 ng/ml
Doses to be individualized and titrated
37. Imipramine – Adverse effects
1. Anticholinergic effects: Dry mouth, bad taste,
constipaton, urinary retention etc.
2. Dysphoric state or mania - suicide
3. CVS:
Postural hypotension – older patient and overdose
Arrhythmia – with IHD
1. Weight gain – not with bupropion and SSRI
2. Seizure – in children
3. Sedation, mental confusion etc. – more with
amitriptyline
4. Sweating and fine tremor
38. Imipramine – Drug Interactions
1. TCAs and Sympathomimetics (Cough and
cold)
2. TCAs and MAO inhibitors – Hypertensive
crisis
3. TCAs and SSRIs – SSRIs inhibit
metabolism of TCAs
4. Anticholinergic property – delay absorption
of other drugs
39. Imipramine - Drawbacks
Low safety margin
Anticholinergic, CVS and neurological side
effects
Therapeutic lag (2-4 wks)
Variable patient response
40. SELECTIVE SEROTONIN REUPTAKE
INHIBITORS
Drugs: Fluoxetine, Fluvoxamine, Sertraline and
Citalopram
Similar antidepressant action
Relatively safe and better patient acceptability
Some patients not responding to TCAs may respond
with SSRIs
Because of absence of psychomotor and cognitive
impairment - Preferred in prophylaxis of recurrent
depression
41. SELECTIVE SEROTONIN REUPTAKE
INHIBITORS
Relative advantages:
– No sedation, so no
cognitive or psychomotor
function interference
– No anicholinergic effects
– No alpha-blocking action,
so no postural hypotension
and suits for elderly
– No seizure induction
– No arrhythmia
Drawbacks:
– Nausea is common
– Interfere with ejaculation
– Insomnia, dyskinesia,
headache and diarrhoea
– Impairment of platelet
function – epistaxis
– Serotonin Syndrome:
Mental confusion,
hallucinations, sweating,
hyperthermia, twitching of
muscle, clonus and
convulsion.
42. SELECTIVE SEROTONIN REUPTAKE
INHIBITORS
Fluoxetine:
– Prototype of SSRIs
– Slow action and not used for rapid effects
– Longest acting – 2 days, t1/2 = 2 days
– Used in depression and OCDs in adult and
children
43. SSRIs – Pharmacokinetic comparison
Dose
mg/day
Drug
interaction
Half life Steady
state
(Days)
Fluoxetine 5-20 high 2-4 days 30-60
Sertraline 50 low 26 Hrs 7-14
Paroxetime 20 high 20 Hrs 10-14
Citalopram 20-40 low 35 Hrs 7
44. Atypical Antidepressants
1. Trazodone:
Weak 5-HT uptake block, α – block, 5-HT2 antagonist
No anticholinergic action
No arrhythmia
No seizure
ADRs: Priapism, Postural Hypotension
2. Venlafaxine:
SNRI (Serotonin and NA uptake inhibitor)
Fast in action
No cholinergic, adrenergic and histaminic interference
Raising of BP
45. Atypical Antidepressants – contd.
3. Mirtazapine:
NaSSA action (Noradrenaergic and specific serotonergic
antidepressant) – enhancement of NA release and specific 5-
HT1 receptor action
Blockade of 5-HT2 and 5-HT3
No anticholinergic or antidopaminergic action
4. Bupropion:
Inhibitor of DA and NA uptake (NDRI)
Non-sedative but excitant property
Used in depression and cessation of smoking
Seizure may precipitated
46. Antidepressants - Uses
1. Endogenous Major Depression:
Aim: Relieve symptoms of depression and restore Normal
social Behavior
1st
choice – SSRI (atypical ones also may be considered)
TCAs – in non-responsive cases
(TCAs have to be used in severe depression in adults)
MAO –A inhibitors in mild and moderate cases
Maintenance – by TCAs (Imipramine 100 mg)
Combined with Lithium in Bipolar disorder
Newer ones are not recommended in children – suicide
chance
47. Antidepressants (Uses) – contd.
2. Obsessive Compulsive Disorder (OCD) and Phobic states:
(SSRIs are useful)
– Compulsive eating in Bulimia
– Body dysmorphic disorder
– Compulsive buying
– Kleptomania
3. Anxiety Disorders: BZD
4. Neuropathic pain: Imipramine, Amitriptyline – post herpetic neuralgia
4. Attention Deficit Hyperactivity Disorder: TCAs
5. Enuresis
6. Migraine: Amitryptiline as prophylactic
49. What is anxiety?
Anxiety is a normal reaction to stress
It helps one deal with a tense situation in the
office, study harder for an exam, keep
focused on an important speech
In general, it helps one cope
But when anxiety becomes an excessive,
irrational dread of everyday situations, it has
become a disabling disorder
50. Antianxiety Drugs – contd.
Five major types of anxiety disorders are:
– Generalized Anxiety Disorder (GAD)
– Obsessive-Compulsive Disorder (OCD)
– Panic Disorder
– Post-Traumatic Stress Disorder (PTSD)
– Social Phobia (or Social Anxiety Disorder)
GAD:
– Excessive, exaggerated anxiety and worry about everyday life
events with no obvious reasons for worry
– always expect disaster and can't stop worrying about health,
money, family, work, or school
– interferes with daily functioning, including work, school, social
activities, and relationships.
52. What are the Drugs?
Benzodiazepines: Alprazolam, Diazepam,
Chlordiazepoxide, Oxazepam and Lorazepam
Older Drugs: Barbiturates, Chloral hydrate and
Meprobamate
Azapirones: Buspirone, Gepirone and Isapirone
Others: Propranolol, Imipramine Fluoxetine and
Zolpidem etc.
53. Antianxiety Drugs – BZDs
High potency BZDs are useful
Slow and Long duration of action
Relieve anxiety at low doses – no generalized CNS depression
Prescribed for short period – especially for alcohol and drug
abuse persons
Less cognitive impairment
At low dose – CVS and Respiratory side effects are less
Withdrawal syndrome – tapering of Doses
Clonazepam - social phobia and GAD
Lorazepam - panic disorder
Alprazolam - panic disorder and GAD
Diazepam – acute panic state and organic disease anxiety
54. Antianxiety Drugs – Buspirone
No marked sedation and euphoria
No direct effect on GABA or BZD receptors
No physical dependence or tolerance
No muscle relaxant, no anticonvulsant or no
extra pyramidal effects
No functional and cognitive impairment
No cross tolerance to other anxiolytics and
little abuse potential
55. Buspirone – contd.
Partial agonist action on presynaptic auto receptor 5-
HT1A – reduces serotonergic activity in dorsal raphe
Antagonist of certain 5-HT1A post synaptic receptors
Weak D2 action but no antipsychotic effect
Adaptive changes after chronic treatment – reduction
in 5-HT2 receptors in cortex
Given orally, absorbed rapidly – high 1st
pass
metabolism, active metabolite – urine and faeces
Dose: 5-15 mg dose
56. Antianxiety Drugs - Propranolol
Reduces symptoms of anxiety
Symptoms: Sympathetic overactivity –
palpitation, tachycardia, rise in BP, sweating,
tremor, GIT hurrying etc
No action on psychological symptoms – fear,
tension etc.
Useful in examination fear, public
appearance etc.
57. Pharmacotherapy of Anxiety
Anxiety is a Physiological phenomenon
Start medication only when marked impairment of performance
Start with a BZD according to the type of disorder at smallest
dose possible
Doses are found out by titrating with the symptoms
Usually start with ½ or 2/3rd
of the normal dose at bed time
If required the rest of the doses be given at day time
Simultaneously treat the primary cause – hypertension, Peptic
ulcer etc.
SSRIs and Buspirone may be used in severe cases but not in
acute cases
58. Pharmacotherapy of Anxiety – contd.
Beta-blockers may be given as adjuncts
Withdraw anxiolytics, if required in tapering doses
Lifelong therapy may be required for some patients
but avoid short acting drugs for long therapy
Monitor for Drug interactions
In GAD – counseling, mental relaxations and
Behavioural therapy
Avoid:
– Excess of Cola or Coffee (stimulants)
– Combination of alcohol, antihistamines, anticholinergics
Affective disorders are the diseases of mind. They affect the state of mind of the sufferers. It may be from mild disorder to life threatening one. There is serious biological, social, psychological and behavioural factors invilved.
One of the common disorder is MANIA where a person is in hyperactivity, irritable mood, reuced sleep, uncontrolled speech and thought
Bipolar disorders are special category of disorders which where there is mood swing from depression to mania. This special category is treated by Mood stabilizers. Lithium – instead of NaCl in cardiac patient caused severe intoxication.
NA neruones mostly arise from locus ceruleus (pons) and lateral tegmentum in Midbrain
Serotonergic neurones arise from raphe nucleus of pons
MAO degrades some of NA within the neurones even after uptake. Inhibition of this MAO enzyme may accumulate NA in excess and may cause hypertensive crisis and manic state
Cheese reactioon – Indirectly acting sympathomimetic amines escape degradation by MAO, reaches systemic circulation and displace large amount of NA from nerve endings leading to hypertensive crisis. Treated with phentolamine and prazosin
Continued stimulation of cells with agonist results in desensitization (adaptation/refractoriness/down-regulation) such that the effect followed on subsequent exposure is diminished
Serotonin syndrome is a potentially life-threatening adverse drug reaction that may occur following therapeutic drug use, inadvertent interactions between drugs, overdose of particular drugs, or the recreational use of certain drugs.
Obsessions are involuntary, seemingly uncontrollable thoughts, images, or impulses that occur over and over again in your mind.
Fear of being contaminated by germs or dirt or contaminating others
Fear of causing harm to yourself or others
Compulsions are behaviors or rituals that you feel driven to act out again and again. Usually, compulsions are performed in an attempt to make obsessions go away.
Phobia - ,specific phobia and social phobia