PH3.5 | PH3.5 | Antidepressants and Antipsychotics — SDL Guide — Summary & Reflection

KEY TAKEAWAYS

Antidepressants: SSRIs (first-line — SERT block; serotonin syndrome risk with MAOIs; discontinuation syndrome); SNRIs (SERT+NET; neuropathic pain); TCAs (multiple receptors; fatal in overdose — Na⁺-channel block; TCA overdose → IV NaHCO₃); MAOIs (phenelzine: tyramine hypertensive crisis with aged food; moclobemide = RIMA — safer). Antipsychotics: Typical (haloperidol — D2 block; high EPS: acute dystonia/akathisia/drug-induced parkinsonism/TD); Atypical (D2+5HT2A; lower EPS; clozapine — treatment-resistant schizophrenia — mandatory WBC monitoring for agranulocytosis; metabolic syndrome). NMS (antipsychotic → hyperthermia + rigidity — treat with dantrolene + bromocriptine) vs serotonin syndrome (SSRI+MAOI → clonus + agitation — treat with cyproheptadine). SSRI+MAOI: minimum 14-day washout (fluoxetine: 5 weeks).

REFLECT

A 28-year-old man with schizophrenia is brought to the emergency department by his family. He stopped his risperidone six weeks ago because of weight gain and sexual dysfunction. He is acutely psychotic — agitated, hallucinating, refusing oral medication. His family asks you why he cannot simply be given 'strong medicine to fix his brain permanently'. Walk through your pharmacological management plan: acute phase → maintenance → long-term adherence strategy. How does risperidone's receptor profile explain the adverse effects that led to non-adherence, and what alternative might reduce those specific side-effects? What would you counsel regarding long-acting injectable antipsychotics?