Psychotropic Medications: Essentials for Finals Claire Wilson
Antipsychotics • Antidepressants • Mood stabilisers (esp lithium) • A little on TCA overdose • A little on ECT
Dopamine Pathways • Mesolimbic pathway • Mesocortical pathway • Nigrostriatal pathway • Tuberoinfundibular pathway
Antipsychotics • Typicals Haloperidol Chlorpromazine • Atypicals Olanzapine Risperidone Quetiapine Aripiprazole Clozapine
Side effects • Histamine • Alpha-adrenergic • Muscarinic • Dopamine
Acute Dystonia • Torticollis: painful contraction of sternocleidomastoid. • Oculogyric crisis: opisthotonus, upward deviation of eyes, ocular pain. • Watch out in young, neuroleptic-naïve patients. • Also get this with metoclopramide.
Parkinsonian side effects • Pill-rolling tremor. • Cog-wheel rigidity. • Bradykinesia. • Expressionless ‘mask like’ face. • Shuffling gait with reduced arm swing and difficulty initiating movement.
Akathisia • Restless legs. • Feeling of tension. • Inability to tolerate inactivity. • Subjective and objective. • Watch out- increased risk of suicide.
Tardive dyskinesia • Occurs gradually after long-term treatment. • Can involve trunk, arms, hands but most commonly face. • Lip smacking, chewing movements.
Treatment • Adjust regimen- reduce dose, switch class. • Acute dystonia- give IM or oral procyclidine. • Long-term use of procyclidine for Parkinsonian side effects (tremor only). • Beta blockers for akathisia. • Tardive dyskinesia- nothing.
Also watch out for… • Prolongation of the QT interval. • Reduced seizure threshold (more so with chlorpromazine).
Side effects of atypicals • Weight gain. • Hyperlipidaemia. • Development of T2DM.
Neuroleptic malignant syndrome • Rare but fatal. • Occurs with too much dopamine depletion. • Pyrexia, muscle cramps or rigidity, delirium or coma and autonomic instability. • Elevated CK and WCC. • Supportive management and bromocriptine.
Sample MEQ A 23-year old student has recently received a diagnosis of schizophrenia. She has been prescribed haloperidol. Three days after commencing it she complains of pain in her neck and is noticed to have her face twisted to one side. • What medication side effect is she suffering from? • What is the underlying medication action that causes this side effect, and in which brain region does it occur? • List 3 other type of side-effect caused by the same drug action. • Name 2 management strategies to counteract these side-effects. • Name 2 antipsychotic drugs least likely to cause these side-effects.
Monoamine Theory of Depression • Deficiency of synaptic monoamines. • Serotonin (5-HT). • Noradrenaline (NA). • Dopamine (to a lesser extent). • Anti-depressants increase levels in synaptic cleft. • Inhibit re-uptake. • Inhibiting breakdown.
First generation antidepressants • MAOIs inhibit monoamine oxidase enzyme so reduce breakdown of 5-HT, NA and dopamine. • E.g. phenelzine. • They are old, not as effective as newer agents and have lots of drug interactions. • The ‘Cheese Reaction’. • TCAs block reuptake of 5-HT (and NA to a certain extent). • E.g. amitriptyllline, dothiepin, imipramine. • Remember HAMD for side effects (minus the D).
TCA overdose • Cardiac toxicity-watch the ECG. • CNS toxicity-seizures. • Sodium bicarbonate.
Second generation ‘new’ antidepressants • First line: SSRIs e.g. fluoxetine, citalopram, sertraline. • Second line: SNRIs e.g. venlafaxine, duloxetine. • Third line: NaSSAs e.g. mirtazepine. • Also NARIs e.g. reboxetine. • Noradrenaline-dopamine reuptake inhibitors e.g. bupropion can be used as add-on, anxiolytic and also smoking cessation aid.
Side effects of SSRIs • Sexual dysfunction. • GI upset, including GI bleeds. • Insomnia. • Suicidality? • Discontinuation syndrome.
Serotonin Syndrome • A.k.a. serotonin storm. • Similar to neuroleptic malignant syndrome, e.g. hyperthermia BUT no bradykinesia, muscle rigidity or raised CK or WCC. • Hyperkinesia and clonus. • Mild • Moderate • Severe • Supportive management and cyproheptadine.
Prescribing antidepressants • Few weeks for them to feel the benefit of the drugs. • Wait about six weeks before reviewing the patient. • Continue for at least 4-6 months after resolution of symptoms. • Relieve patient concerns e.g. you will not become addicted! • Be sure they are unipolar depressive and not bipolar.
Sample MEQ You are called out to see a 38-year old woman who has not left the house since loosing her job two months ago. Her daughter tells you see has not been eating properly and has stopped washing and getting dressed. You suspect she is suffering from reactive depression. • Name three other biological symptoms that would suggest depression. • After taking a history and examining Mrs. Park you both decide that trying an anti-depressant is the best option. Give three classes of anti-depressants, an example and the main side effect for each class. • Describe the mechanism of action of these three classes of anti-depressants. • You start Mrs. Park on Fluoxetine. What would be your starting dose? • Name two types of non-pharmacological treatments that Mrs. Park may benefit from.
Mood stabilisers • Valproate • Carbamazepine • Lithium • Lamotrigine • Gabapentin • Antipsychotics • Can also use benzos and ECT
Lithium toxicity • Narrow therapeutic range 0.4-1.0 nmol/L. • Regular monitoring of plasma levels- watch out when dehydrated-toxicity. • Cardiotoxicity • Neurotoxicity
Lithium side effects • Regular TFTs, U&Es and ECGs and prior to commencing. • Hypothyrodisim. • Renal tubular necrosis. • Nephrogenic diabetes insipidus. • Can also cause fine tremor, nausea, vomiting, diarrhoea and metallic taste in mouth.
Psychotropics in the perinatal period • No lithium in pregnancy- teratogenic- Ebstein’s anomaly. • No anticonvulsants- neural tube defects. • If bipolar patient needs something in pregnancy, give low dose atypical antipsychotic. • SSRIs in pregnancy- controversial.
ECT • The last option after drugs have failed. • Unknown mode of action. • 6-12 treatments at 3 day intervals. • Procedure. • Headache. • Amnesia?