AO1
TYPICAL ANTIPSYCHOTICS
- CHLORPROMAZINE = taken as TABLETS, SYRUP or INJECTION – most dosages go up to 400mg to 800mg
- STRONG ASSOCIATION between CHLORPROMAZINE and the DOPAMINE HYPOTHESIS
- They work as ANTAGONISTS which BLOCK DOPAMINE RECEPTORS in the SYNAPSES of the brain, REDUCING the action of DOPAMINE
- Initially dopamine production BUILDS UP but then it is REDUCED, IT NORMALISES NEUROTRANSMISSION in KEY AREAS of the brain – REDUCING SYMPTOMS like hallucinations
- CHLORPROMAZINE is also an EFFECTIVE SEDATIVE – related to its effect on HISTAMINE RECEPTORS – used to CALM PATIENTS, not only with SCHZOPHRENIA, but with other CONDITIONS
ATYPICAL ANTIPSYHOTICS
- created to MAINTAIN/IMPROVE the EFFECTIVENESS of the rugs and to MINIMISE SIDE EFFECTS
- CLOZAPINE – when REMARKETED it showed to be MORE EFFECTIVE than TYPICAL ANTIPSYCHOTICS and to be used when other treatments FAILED
PEOPLE take a BLOOD TEST REGULARLY to check that they are NOT DEVELOPING AGRANULOCYTOSIS (what it caused initially before the remarket)
CLOZAPINE is NOT used as an INJECTION due to its FATAL SIDE
CLOZAPINE binds DOPAMINE RECEPTORS TOGETHER but also acts on SERETONIN and GLUTAMATE RECEPTORS = BETTER MOOD AND LOWERS DEPRESSION and ANXIETY as well as INCREASING COGNITIVE FUNCTIONING
it is usually used when they are considered at HIGH RISK OF SUICIDE – 30% TO 50% of patients at some point
- RISPERIDONE – MOST RECENT, developed as an attempt to be as effective as CLOZAPINE but WITHOUT THE SIDE EFFECTS
- RISPERIDONE is believed to BIND DOPAMINE and SERETONIN RECEPTORS and binds them to dopamine receptors MORE STRONGLY than CLOZAPINE = more EFFECTIVE and there is EVIDENCE it leads to LESS SIDE EFFECTS
AO3
- EVIDENCE FOR EFFECTIVENESS: THORNLEY ET AL: REVIEWED studies comparing the effects of CHLORPROMAZINE to CONTROL CONDITIONS using a PLACEBO – data from 13 TRIALS with 1121 PARTICIPANTS showed that CHLORPROMAZINE was associated with BETTER OVERALL FUNCTIONING and LOWER SYMPTOM SEVERITY – data from 3 TRIALS with 512 PARTICIPANTS showed that the RELAPSE RATE was also lower for CHLORPROMAZINE
ATYPICAL ANTIPSYCHOTICS – MELTZER: concluded that CLOZAPINE is MORE EFFECTIVE than TYPICAL ANTIPSYCHOTICS and other typical antipsychotics – effective in 30% – 50% of treatment-resistant cases where typical antipsychotics have failed // OTHER STUDIES compared CLOZAPINE and others like RISPERIDONE but results have been INCONCLUSIVE, due some patients responding BETTER TO ONE THAN ANOTHER
- SERIOUS SIDE EFFECTS: TYPICAL ANTIPSYCHOTICS – DIZZINESS, AGITATION, SLEEPINESS, STIFF JAW, WEIGHT GAIN and ITCHY SKIN and long-term use – TARDIVE DYSKINESIA = caused by DOPAMINE SUPERSENSITIVITY and includes INVOLUNTARY FACIAL MOVEMENTS like grimacing, blinking and lip-smacking à MOST SERIOUS = NEUROLEPTIC MALIENANT SYNDROME – as the drug stops dopamine action in the HYPOTHALAMUS – HIGH TEMPERATURE, DELIRIUM and COMA and can be FATAL (0.1% TO 2% of people due to dosage)
ATYPICAL were developed to STOP SIDE EFFECTS and were generally succeeding BUT side effects STILL EXIST in those taking CLOZAPINE so they have a BLOOD TEST to alert doctors of AGRANULOCYTOSIS (blood condition)
- USE OF ANTIPSYCHOTICS DEPENDS ON THE DOPAMINE HYPOTHESIS: LOTS of EVIDENCE to show that the ORIGINAL HYPOTHESIS ISN’T FULLY COMPLETE (what antipsychotics rely on) as in SOME PARTS of the brain the DOPAMINE LEVELS are TOO LOW – if true then it’s NOT CERTAIN how antipsychotics (ANTAGONISTS) help with SCHIZOPHRENIA. In our MODERN UNDERSTANDING, ANTIPSYCHOTICS SHOULDN’T WORK
- PROBLEMS WITH THE EVIDENCE FOR EFFECTIVENESS: HEALY: some successful trials have had their data published MULTIPLE TIMES, EXAGGERATING the evidence for POSITIVE EFFECTS and because they have CALMING EFFECTS, it is easy to show that they have some positive effects on patients – NOT the same as saying they really reduce the severity of psychosis + MOST PUBLISHED studies assess SHORT-TERM BENEFITS rather than LONG-TERM and compare patients who keep taking ANTIPSYCHOTICS with those SUFFERING WITHDRAWAL (having just stopped taking them)