Antipsychotics - extrapyramidal side-effects

doctor_b · 10-05-07, 11:57

Antipsychotics are the treatment of choice in schizophrenia.

Typical antipsychotics (e.g. haloperidol, chlorpromazine) are effective in treating the positive symptoms of schizophrenia (hallucinations (often auditory, delusions, disorganised speech and behaviour); atypicals (e.g. risperidone, clozapine) are more appropriate in managing negative symptoms (5As - alogia, affect flattening, anhedonia, avolition, attention-deficit).
There is no gain without pain, however - haloperidol has a High incidence of extrapyramidal side-effects and a low incidence of autonomic effects, while the opposite is true of chlorpromazine.
The natural history of the extra-pyramidal effects is:

4 hours: Acute dystonia - The patient has muscle spasm or stiffness (e.g. torticollis, trismus), tongue protrusions and twisting, opisthotonus and oculogyric crisis (forced sustained deviation of the head and eyes). These are most common in young men. Treat by giving antihistamines (diphenhydramine) or anticholinergics (benztropine).

4 days: Akathesia - The patient has a subjective feeling of restlessness. Look for constant pacing, alternating sitting and standing and inability to sit still. Beta-blockers (atenolol) are helpful here.

4 weeks: Akinesia (Parkinsonism) - Patient has stiffness, cogwheel rigidity, shuffling gait, mask-like facies and drooling. Parkinsonism is more common in older women. Try antihistamines (diphenhydramine) or anticholinergics (benztropine).

4 months - years: Tardive dyskinesia - Most commonly, the patient has perioral movements (darting, protruding tongue, chewing, grimacing, puckering). These patients may also have involuntary choreoathetoid movements of the head, limbs and trunk. There is no known treatment for tardive dyskinesia; consider, however, discontinuing the antipsychotic and switching to clozapine. [Nb! weekly Full Blood Counts are required to monitor for agranulocytosis]

Anytime: Neuroleptic malignant syndrome - This is a life-threatening condition. The patient has rigidity, mutism, obtundation, agitation, high fever (up to 107F), high creatine phosphokinase (often >5000), sweating and myoglobinuria. Treatment: first discontinue antipsychotic; then provide supportive care for fever and renal shutdown (due to myoglobinuria); finally administer dantrolene (just as in malignant hyperthermia).

10-05-07, 11:57	#1
doctor_b Gary Administrator Join Date: Jan 2006 Location: Dublin, Ireland Age: 31 Posts: 145	Antipsychotics - extrapyramidal side-effects Antipsychotics are the treatment of choice in schizophrenia. Typical antipsychotics (e.g. haloperidol, chlorpromazine) are effective in treating the positive symptoms of schizophrenia (hallucinations (often auditory, delusions, disorganised speech and behaviour); atypicals (e.g. risperidone, clozapine) are more appropriate in managing negative symptoms (5As - alogia, affect flattening, anhedonia, avolition, attention-deficit). There is no gain without pain, however - haloperidol has a High incidence of extrapyramidal side-effects and a low incidence of autonomic effects, while the opposite is true of chlorpromazine. The natural history of the extra-pyramidal effects is: 4 hours: Acute dystonia - The patient has muscle spasm or stiffness (e.g. torticollis, trismus), tongue protrusions and twisting, opisthotonus and oculogyric crisis (forced sustained deviation of the head and eyes). These are most common in young men. Treat by giving antihistamines (diphenhydramine) or anticholinergics (benztropine). 4 days: Akathesia - The patient has a subjective feeling of restlessness. Look for constant pacing, alternating sitting and standing and inability to sit still. Beta-blockers (atenolol) are helpful here. 4 weeks: Akinesia (Parkinsonism) - Patient has stiffness, cogwheel rigidity, shuffling gait, mask-like facies and drooling. Parkinsonism is more common in older women. Try antihistamines (diphenhydramine) or anticholinergics (benztropine). 4 months - years: Tardive dyskinesia - Most commonly, the patient has perioral movements (darting, protruding tongue, chewing, grimacing, puckering). These patients may also have involuntary choreoathetoid movements of the head, limbs and trunk. There is no known treatment for tardive dyskinesia; consider, however, discontinuing the antipsychotic and switching to clozapine. [Nb! weekly Full Blood Counts are required to monitor for agranulocytosis] Anytime: Neuroleptic malignant syndrome - This is a life-threatening condition. The patient has rigidity, mutism, obtundation, agitation, high fever (up to 107F), high creatine phosphokinase (often >5000), sweating and myoglobinuria. Treatment: first discontinue antipsychotic; then provide supportive care for fever and renal shutdown (due to myoglobinuria); finally administer dantrolene (just as in malignant hyperthermia).
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