Psychological medicine

Treatment of Psychosis

  • Early intervention improves outcome, reduces disruption/trauma („collateral damage‟), etc. Important given stage of life (adolescence) and the potential problems for subsequent social and occupational development etc
  • Treatment programme involving health professionals, family members, support agencies, and cultural/community context
  • Brain‟s ability to process and interpret information is affected Þ think carefully about how information conveyed is received. Keeps the facts simple, avoid distractions and pressure, ask one question at a time, give plenty of time to answer
  • Biological treatment: treat early, immediately if psychotic, key issue with maintenance medication is compliance
  • Psychological: supportive, education, self-care skills. Social skills training and community integration skills ® overcome withdrawal ® significant ¯ in readmissions
  • Social: assertive (to combat stigma), community care
  • Relapse prevention: understanding drugs, warning signs, prognosis, side effects

Antipsychotic Medication

  • Neuroleptics or major tranquillisers
  • May also use lithium, carbamazepine, antidepressants and benzodiazepines for psychosis
  • Reduced risk of relapse in schizophrenia, but 40% will still relapse within a year
  • Two effects:
    • Reduces delusions and hallucinations (may take 1 –2 weeks)
    • Tranquillising/calming effect (¯acute agitation, immediate effect)
  • For first presentation, treat with low dose and use atypicals (¯side effects ® ­compliance). Use adjunctive long acting benzodiazepine for first few weeks to sedate and ¯agitation
  • Can be administered orally, IM, IV and some as depot (but not yet for atypicals)
  • Side effects range over sedation, extra-pyramidal, anti-cholinergic and hypotensive
  • All relatively effective at reducing positive symptoms, but „atypicals‟ better than „typicals‟ at reducing negative symptoms (eg ¯motivation, interest, lack of emotional display, restricted speech)
  • All have hepatic elimination

Typicals (ie Older antipsychotics)

  • Mode of action: block dopamine (D2) receptors. Most also have low affinity for 5HT2 receptors. Varying amounts of anticholinergic, antihistamine and anti a-1 effects
  • Adverse Effects:
    • Extrapyramidal Syndromes (EPS):
      • Acute: Occur early in treatment – usually first two months.
      • Dystonias (muscle cramps and spasms): treat with benztropine parenterally 
  • Akathisia (restlessness): treat with b blocker or benzodiazepine 
  • Parkinsonism (tremor, cog wheel rigidity, bradykinesia, mask like face) – may improve with time 
  • Anticholinergics only indicated in those whose antipsychotic dose cannot be safely reduced. (= antiparkinsonian medication, eg antimuscarinic drugs such as Cogentin)
  • Tardive Dyskinesia: 
    • Late onset dyskinetic syndrome due to antipsychotic drug treatment. Usually months or years after treatment
    • Fairly common: 15 – 30% 
    • Slow, repetitive involuntary movements of mouth/face, and maybe limbs and trunk. Disappear during sleep
    • Risk factors: old age, organic brain disease, negative symptoms, alcohol abuse
    • Irreversible in 50%
    • No established protocol for treatment: try dose reduction, lithium, or change to clozapine
    • Made worse by dopaminergic agonists and anticholinergics
  • Other effects:
    • Sedation
    • Anticholinergic effects (dry mouth, constipation, blurred vision, urinary hesitancy) 
    • a blockade (postural hypotension, tachycardia, delayed ejaculation)
    • Endocrine effects (­PRL, marked weight gain, ¯libido, impotence, amenorrhoea) 
  • Neuroleptic Malignant Syndrome: Rare (0.2 – 1%) with hyperthermia, rigidity, and impaired consciousness. 20% mortality. Emergency treatment (cooling, fluids, etc)
  • Interactions:
    • Potentiate sedation with hypnotics, alcohol, opioid analgesics
    • Fluoxetine increases risk of EPS

Atypicals

  • Clozapine:
  • Mode of action: numerous receptors: D1, D2, D4, 5HT2, blocks a-1, H1 and muscarinic receptors
    • Effective in individuals not responsive to classical antipsychotics, effective for positive and negative symptoms, no extrapyramidal side effects, no impact on sexual or reproductive function.
    • Side effects:
      • Sedation, tachycardia, constipation, weight gain, and seizures (3% at highest dose) 
      • Agranulocytosis/blood dyscrasias in 1-2 % by 1 year, most in first 18 weeks ® regular blood tests 
      • Potent enzyme inhibitor: significant drug interaction potential
      • Serotonergic crisis with SSRIs
      • Hypersensitivity syndrome: PUO, arthritis, rash
      • Prolongation of QT
      • Myocarditis
  • Risperidone:
    • Mode of action: binds to 5HT2 and D2 receptors, antagonises H and a-1 receptors 
    • Similar efficacy as other antipsychotics for positive symptoms. Effective for negative side effects and also affective symptoms (depression, anxiety). 
    • Some dose related extrapyramidal side effects. ­PRL at high doses. Also insomnia, agitation, anxiety, headache
  • Olanzapine:
    • Mode of action. Similar to clozapine.  Like clozapine has minimal impact on PRL
    • Similar efficacy to haloperidol, but more impact on negative symptoms
    • Sedation, headache, dizziness, constipation, dry mouth, weight gain