Antidepressants and anti-manic drugs

Question 1

MAOIs

Answer 1

MAOI-A: phenylzine
MAOI-B seligiline… used for parkinson’s

MOA for MAOI-A: inhibits MAOI-A, which increases the amount of NE / 5-HT that can be release from post-synaptic vesicles
Adverse effects: sexual dysfunction, interactions with sympathomimetic drugs such as epinephrine and amphetamines. Interactions with tyramine because it is broken down by MAO-A, so this will stimulate excessive NE & 5-HT release, leading to HTN crisis
Uses: depression

Question 2

TCAs

Answer 2

Amitriptyline and Imipramine

MOA: inhibit re uptake of 5-HT & NE by blocking NT-specific transporters

Adverse effects: sexual dysfunction, mAchR antagonist effects via inhibition, Na+ channel blocker effects

Contraindications: patients taking Na channel blockers for heart, patients on SSRIs, and antimuscarinic drugs
Uses: depression, anxiety, pain syndromes

Amitriptyline: less drug-drug interactions because less metabolism

Question 3

SSRIs

Answer 3

Fluoxetine and Citalopram

MOA: inhibit 5-HT re uptake on pre-synaptic neurons, which increases 5-HT that can bind to 5-HT1 receptors

Adverse effects: Sexual dysfunction / Serotonin syndrome with TCAs / weight gain & suicidal thoughts

Uses: OCD / PTSD / depression / Eating disorders / Depression for children

Pharmacokinetics: @ high doses, SSRIs can inhibit CYP metabolism. Citalopram has lower risk of CYP inhibition, while Fluoxetine has the highest risk. SSRIs can inhibit the metabolism of codeine into its active form

Question 4

SNRIs

Answer 4

Venlafaxine and Duloxetine

MOA: similar to TCA, which inhibit the re uptake of 5-HT and NE, yet have no affect of macho and sodium channels

Question 5

Noradrenergic Dopaminergic reuptake inhibitors

Answer 5

Bupropion

MOA: block reuptake of NE and DA, with no effect on serotonin

ADRs: no sedation, weight gain, or suicidal thoughts or sexual dysfunction

Uses: depression for patients that complained of decreased sexual libido

Question 6

Alpha 2 receptor inhibitors

Answer 6

Mirtazepine

MOA: inhibit alpha 2 reuptake of NE and 5-HT on pre-synaptic terminals

ADRs: weight gain

Uses: Mirtazepine is first line therapy for patients with depression that suffer from anorexia

Question 7

Lithium

Answer 7

MOA: inhibit inositol phosphates
Adverse effects: tremors, weight gain, electrolyte imbalance, mimics high sodium load
Uses: acute mania episodes and prophylaxis of future episodes

Question 8

Alternative Tx for mania

Answer 8

Anticonvulsants- valproic acid / carbamazepine / lamotrigine

Antipsychotics - quetiapine / risperidone / aripiprazole