University:
Western Sydney University
Course:
MEDI 2003 | Clinical Sciences 2
Academic year:

2024
Views:

100

Pages:

3
Author:

Mariam A.

Antidepressants Basics    Block reuptake. Inhibit enzymatic breakdown. Inhibit presynaptic autoregulation (block presynaptic inhibitor alpha2 adrenergic and potentiate release). Classes  Fluoxetine (Prozac) – SSRIs.  Mianserin and mirtazapine – inhibit presynaptic alpha2 adrenergic autoreceptors.  Moclobemide – reversible MAO-A (5-HT, NA and dopamine) inhibitor; MAO-B (and tyramine) at higher doses.  Reboxetine – selective NARI.  Venlafaxine – S and NA (higher dose) and weak dopamine RI. Side       effects Nausea. Impaired orgasm. Reduced libido. Withdrawal syndrome. Sweating. Tremor. Discontinuation syndrome with abrupt stoppage of SSRIs  Flu-like symptoms.  Malaise.  Dizziness.  GIT.  Paraesthesia. Serotonin syndrome  Risk with interactions.  Medical emergency.  Abdominal cramps, agitation, myoclonus, diarrhoea, tremor, coma, tachycardia, hypotension (or hypertension), confusion, disorientation, profuse sweating, fever, death. Venlafaxine  Serotonin-noradrenaline reuptake inhibitor (SNRI).  Administration: o Starting dose = 75mg. o Range = 37.5 – 225mg. o Max = 375mg.  Side effects: o Nausea. o Hypertension. o Dizziness. o Insomnia.  o Abnormal ejaculation. Low dose SSRI effect is comparable to high dose SNRI effect. Moclobemide  Reversible and selective MAO-A inhibitor. o 5-HT, NA and dopamine. o MAO-B and tyramine at higher doses.  Administration: o Starting dose = 300mg. o Range = 300 – 600mg. o Max = 1500mg.  Side effects: o Nausea. o Dizziness. o Headache. o Tremor. o Agitation. o Insomnia. Prescribing anti-depressants  Moderate to severe major depression.  Patient preference.  Symptoms two years + duration.  Previous response.  Strong family history.  Previous episodes.  Incomplete response psychotherapy. Variable response  Many patients require a trial of two different agents.  Genetic/ethnic influences likely important on drug metabolism and responsiveness. o People from Japan poor metabolism of CYP2C19-dependent agents (e.g. citalopram). o People from Africa and Arab have high metabolism of CYP2D6dependent agents (e.g. mianserin). Issues in pregnancy  Nothing completely safe.  All prescribing is on ‘risk/benefit’ basis.  Risks to child and mother of untreated or undertreated depression: o Spontaneous abortions. o Pre-eclampsia. o Premature birth.   o Small-for-dates. o Longer term neurodevelopmental problems. Risks of prescribing: o Toxicity and withdrawal syndrome at birth. o Fluvoxamine and sertraline present in breast milk. o Paroxetine linked cardiac birth defects. Seek ‘up to date’ advice. Psychological strategies  Activity scheduling.  Exercise.  Positive thinking.  Supportive counselling.