Antidepressants and mood stabilizers

Question 1

Class of antidepressants

Answer 1

• TCA (tricyclic amides): inhibition of presynaptic reuptake of NE/5HT/DA (ex: amitriptyline)
• SSRI: inhibition of presynaptic reuptake of 5HT (ex: fluoxetine)
• MAOI: inhibition of monoamine oxidase (ex: phenelzine)
• Others: 5HT2 antagonism (mirtazapine), DA reuptake inhibitor (bupropion)
• Rx can be acute (6-8 wks), months-years (continuation or maintenance), or be lifelong (maintenance)
• Rx of antidepressants to someone w/ bipolar d/o can trigger a manic phase

Question 2

Amitriptyline (Elavil)

Answer 2

• TCA: inhibits the reuptake of NE, 5NT, and DA
• Causes sedation (inhibits histamine), dizziness (inhibits a1 adrenergic), dry mouth and constipation (inhibits cholinergic)
• Is effective and inexpensive
• Major problem: chance of cardiotoxicity/heart block in OD (need ECG baseline and to monitor)

Question 3

Fluoxetine (prozac)

Answer 3

• SSRI
• Causes nausea and diarrhea (agonist of 5HT3)
• Causes headache, sexual changes like delayed ejaculation (agonist of 5HT2)
• 30-50% have sexual side effects
• Safety in OD, does not cause sedation

Question 4

Phenelzine (Nardil)

Answer 4

• MAOI
• Causes dizziness and postural hypotension (a1 inhibition)
• Increases wakefulness and causes insomnia
• Hypertensive crisis when mixed w/ pseudoephedrine or tyramine (no aged cheese or wine)

Question 5

Mirtazapine (Remeron)

Answer 5

• 5HT2 antagonism
• No sexual side effects, nausea, or headache
• Blocks histamine but less sedation due to NE increase
• Main common adverse effect: sedation (due to blocking histamine) and significant weight gain

Question 6

Bupropion (wellbutrin)

Answer 6

• DA/NE reuptake inhibitor
• Helps in cessation of smoking and ADHD
• No sexual dysfunction, no weight gain
• Common adverse effect: insomnia, upset stomach
• Seizure risk: not used in those w/ epilepsy/seizures or those w/ eating d/o particularly bulimia

Question 7

Mood stabilizers

Answer 7

• Rx for bipolar disorder, are taken lifelong to prevent relapse of illness
• Either lithium (more lethal in OD) or valproate (less lethal in OD)

Question 8

Lithium

Answer 8

• Eskalith, lithobid
• Excreted unchanged thru renal
• Inhibits excitatory NT (NE, DA) release, enhances 5HT to help deal w/ depression
• Effective in both stages of the disease, best relapse prevention
• Onset 1-2 wks (less lipophilic), lethal in OD
• Therapeutic level: .6-1.5 mEq/L
• Drug interactions: ibuprofen, caffeine

Question 9

Valproate

Answer 9

• Depakene, Depakote
• Facilitates GABA activity, broad-spectrum anticonvulsant
• For acute mania, mixed mania (rapid cycling)
• Less established relapse prevention
• Onset 2-5 days (lipophilic), much safer in OD
• Hepatic elimination
• Therapeutic level: 50-125 mg/L