Psychiatric Drugs and Medications Q 42
Sheila who has been on a low-potency antipsychotic for 2 weeks has shown minimal response. The most probable explanation is:
A. The client probably has refractory illness
B. The client needs a stronger medication
C. It is too early to see a full therapeutic response
D. The client is definitely not taking the medication
Correct Answer: C. It is too early to see a full therapeutic response.
The initial response may be seen 1 to 2 days after initiation of treatment, with full therapeutic response in approximately 6 to 8 weeks. The first-generation antipsychotics work by inhibiting dopaminergic neurotransmission. Their effectiveness is best when they block about 72% of the D2 dopamine receptors in the brain. They also have noradrenergic, cholinergic, and histaminergic blocking action.
Option A: All dopamine receptor antagonists are available and can be administered in oral form. Except for thioridazine, pimozide, and molindone, all other first-generation antipsychotics can also be given parenterally. Haloperidol and fluphenazine can be delivered in long-acting depot parenteral form.
Option B: These can be administered in oral or parenteral forms. Risperidone, olanzapine, aripiprazole, and paliperidone are available as extended-release or long-acting injectable forms. Clozapine, asenapine, and olanzapine are available in the sublingual formulation.
Option D: Some antipsychotics can be monitored for a plasma therapeutic range. It is recommended to monitor plasma concentrations at a trough, which is at a minimum of 12 hours after the prior dose, and best at 20 to 24 hours after the last dose. Most antipsychotics do not have a well-defined dose-response curve.