Depression and Anxiety Flashcards
two examples of TCAs
- amitriptylline
2. imipramine
SSRIs
- fluoxetine
2. citalopram
SNRIs
- venlafaxine
2. duloxetine
what is an atypical antidepressant
buproprion-NE and Dopamine reuptake inhib
Buproprion pros
against weight gain and smoking
Buproprion cons
epileptogenic
Cheese/Tyramine effect
MAOI however, which irreversibly inhibits MAO Type A, results in prevention of NE breakdown/degradation, hence accumulation of NE. MAO-A inhibition also prevents breakdown of tyramine (tyramine ingested in forms of cheese). Tyramine (sympathomimetic agent) increases the release of NE. The combination can result in large accumulation of NE release with vasoconstriction and BP elevation, presenting with hypertensive crisis. Stop MAOI, treat with IV nitrates and beta-blocker (labetalol).
What do TCAs block?
- NE
- Serotonin
- Histamine
- Alpha-1-adrenergic
- Muscarinic cholinergic
- Voltage sensitive sodium channels
TCAs adverse effects:
anticholinergic: confusion, urinary retention, blurred vision, dry mouth, constipation, tachycardia
antihistamine: weight gain, sedation
alpha blocking: postural hypotension
In which 4 conditions are TCAs contraindicated?
MI
Arrhythmia
closed angle glaucoma
BPH
which TCA is safest in pregnancy and can be used in elderly
amitryptilline
which TCA is used for enuresis
imipramine
Toxic effects of TCAs
cardiotoxic: sinus tachycardia (due to anticholinergic effect, worsened by hypotension);
refractory hypotension (alpha-1 adrenergic receptor blockade with decreased peripheral resistance,
impaired sodium input resulting in impaired myocardial contractility thus contributing to hypotension and decreased cardiac output);
cardiac conduction abnormalities (due to inhibition of fast sodium channels, delayed AV conduction, risk of arrythmias)
CNS toxicity – delirium, lethargy, seizures, coma (inhibition of fast sodium channels in the CNS, antagonism of GABA A receptors, antihistaminic effects)
which SSRI also blocks NE reuptake?
Fluoxetine
SSRI side effects
sexual dysfunction
BUT
no anticholinergic, no antihistamine or cardiac effects
NB CAN POTENTIATE SUIDICIDAL THOUGHTS IN CHILDREN/TEENS SO CHOOSE A TCA FOR THIS AGE GROUP
SSRIs block serotonin uptake in platelets, thus increased risk of bleeding; warfarin and SSRI’s contra-indicated
safe in early preg
Serotonin syndrome
•Neuromuscular hyperactivity:
–tremor, sustained clonus (pathognomonic; mostly if high doses of SSRI’s used, if other serotonergic agents used), hyperreflexia, rigidity
•Altered mental state:
–agitation, confusion
•Autonomic hyperactivity
–fever, sweating, tachycardia, tachypnoea, diarrhoea
e.g. serotonergics - tramadol; linezolid, St. John’s Wort
Treat – stop the drug; benzodiazepines, treat symptomatically
which drug releases NE and serotonin into the synaptic cleft?
mianserin
Mianserin
tetracyclic antidepressants, alpha 2 antagonists. Not a SSRI, not a TCA.
Unlike the tricyclic antidepressants, it does not prevent peripheral reuptake of NE, but releases 5-HT and NE into the synaptic cleft.
Free of anticholinergic side-effects (useful in patients with prostatic enlargement; closed-angle glaucoma), not cardiotoxic, no risk of OD.
Potentially anti-histaminic side-effect with sedation; and weightgain.
Serious risk of neutropenia and agranulocytosis
Venlafaxine
Venlafaxine – SNRI – at lower doses only has serotonin reuptake inhibition; at higher doses has NE reuptake inhibition (not the case with duloxetine, which has uptake inhibition of both at low and high doses). Thus, at lower doses, acts as SSRI. Problem with venlafaxine – discontinuation/withdrawal syndrome; follows interruption/reduction/discontinuation of drug. Can present with paresthesiae, ataxia/dizzyness, lethargy, insomnia, anxiety, agitation. Consider drug only when patient poorly responsive to others.
SNRIs are a bit more difficult to manage, withdrawal
BPMD meds
- Lithium
- Anticonvulsants: sodium valproate, carbamezapine
- lamotrigine-rash
Lithium toxicity
Nephrotoxic
neurotoxic
thyrotoxic
adverse effects lithium
neutrophilia,
weight gain,
polydipsia and polyuria,
not teratogenic
don’t use with NSAIDS, ACE I, thiazide diuretics
treatment anxiety
benzodiazepines
treatment serotonin syndrome
benzodiazepines
