Classic Antipsychotic: Phenothiazine

Mechanism: Blocks D2 receptor, also a-adrenergic and histamine receptors. 

Uses: schizophrenia, relieves "positive"symptoms; pre-anesthetic, sedative, premature ejaculation, severe itching; also manic episodes, EtOH hallucinations, psychosis and hallucinations in drugs of abuse; can be given in ER

Side effects: anticholinergic (blurred vision, constipation, urnary retention, decreased GI motility); Alphar block (postural hypotenstion, inhibits ejactulation); Jaundice necessitates drug change; decreased seizure threshold; retinal deposites; extrapyramidal effects, endocrine effects, tardive dyskinesia, neuroleptic malignant syndrome. 

Dx interactions: increase sedation with sedative hypnotics, increase anticholinergic effects with anticholinergics,

Other drugs: Thioridazine (Mellaril^â)- high antichoinergic acitvity, more sedation+hypotension, less extrapyramidal symptoms

Fluphenazine (Prolixin^â) - "high potency", more selective for DA receptors, less anti-cholinergic activity. more likely to cause extrapyramidal (parkinsons) symptoms

Prochlorperazine (Compazine^â) - for nausea and vomiting

            Trifluoperazine (Stelazine^â) - low anticholinergic activity, high incidence of extrapyramidal effects, less sedation and hypotension

Typical Antipsychotic

Mechanism: Selective D2 blockade, some effect at a1 and 5HT2r, no anticholinergic effects.

Uses: Injected in acute psychotic situations i.e. drug or alcohol abuse; Tourrett's

Dx interactions: increase sedation with sedative hypnotics, increase anticholinergic effects with anticholinergics,

Other drugs: Thiothixene (Navane)- similar to pheonthiazines

Pimozide (Orap)- binds only D2; motor and phonic tics in tourette's; +extrapyramidal +sedation +anticholinergic     

Molindone (Moban) - high extrapyramidal symptoms

Loxapine (Loxitane) - lowers seizure threshold

New gen "Atypical" Antipsychotics

Drug of last choice (agranulocytosis)

Advantages: has greater mesocortical and limbic system specificity -> very low extrapyramidal side effects; no tardive dyskinesia; 

Limiting Side effects: agranulocytosis in 1% of pts; sedation, seizure threshold lower, hypotension, tachy, increased saliva, dizziness, weight gain

Dx interactions: increase sedation with sedative hypnotics, increase anticholinergic effects with anticholinergics,

New Gen. "Atypical" antipsychotics

Use: bipolar disorder, first line schizophrenia (bolded drugs)

Mechanism: Blocks D2, D4 and 5-HT2A receptors; 

Advantages: Useful for "negative" symptoms; Low extrapyramidal symptoms; no agranulocytosis

Disadvantages: Weight gain, increased hyperglycemia and DMII (worst for this); sedation, dizzy, ortho hypo, constipation

Dx interactions: increase sedation with sedative hypnotics, increase anticholinergic effects with anticholinergics, 

Other Drugs: Risperidone (Risperdal^â) - Psychosis; relieves "positive" and "negative" symptoms; w/SSRIs for resistant depression and autism; low extrapyramidla symptoms, binds 5-TH2A and D4 more than D2; prolongs QT interval; may increase mortality in alzheimer's

Quetiapine (Seroquel^â)- bipolar; "positive" and "negative" symptoms, tx resistant depression; little effect on prolactin; weight gain, sedation; bipolar, sedation and depression.

Ziprasidone (Geodon^â) - acute mania, tourett's, prolongs QT interval, seizures possible; hyperprolactinemia                                            Iloperidone (Fanapt^â) - alpha 1 block, no muscarinic effect, may increase QT interval if administered with CYP inhibiting drugs

Paliperodone (Invega^â)

Lurasidone (Latuda^â)

Asenapine (Saphis^â) - possibly not as bad for weight gain; nightmares and PTSD off label

"Dopamine system stabilizer"

Use: first line schizophrenia, Tx resistant depression,

Unique mechanism of action: Activates dopamine receptors when dopaminergic tone is low, blocks them if dopaminergic tone is high; partial D2 adn 5-HT1A agonist

Uses: drug-resistant depression; antipsychotic

Side effects: hyperglycemia, esophageal motility problem (no elderly); ortho hypo, seizures, sedation, inability to regulate body temp; 

Mood stabilizers

Pharmacokinetics: excreted by kidneys, competes with sodium for reabsorption; low sodium diet = increased Li concentration; thiazide diuretics and NSAIDs decrease Li clearance

Dx interactions: Antidepressants = increase mania; 

Diseases that alter the effects or interact with Li: 

Side effects: tremor, nausea, headache, renal effects, decreased thyroid function, edema, weight gain; safe for pregnancy

Tox. Signs: mild tox = nausea, vomit, diarrhea, muscle weakness, fasciculation, hyperreflexia, memory/concentration impaired, slurred speech, sedation, fine tremor, Rash.

 Severe tox = same as above but add clonic-tonic twitch, rep complications, cardiac arrhythmias, renal failure, coma death; Treated with discontinue drug, dialysis/gastric lavage, saline, antiepileptic meds.; increased thirst and urine output, treat with amiloride (prevent Li from getting to collecting duct, prevents ability to block ADH).

Anticonvulsant

Mechanism: Prob block Na channels, may enhance GABA, blocks high freuency repetitive firing; prob wont be asked about mechanism

Uses: 1st choice for mixed seizure disorders; 1st choice for complicated tonic-clonic seizures, 2nd choice for absence, myoclonic seizures, migraine prophylaxis, bipolar (works for alot of things)

Tox: weight gain, hepatotoxicity, Preg cat D

Interactions: other anti-seizure meds

Anticonvulsant

Mechanism: Blocks Na+ Channel, holds channel in inactive state longer; inhibits rapidly firing neurons, little effect on normal neurons

Pharmacokinetics: 1st order at low dose, zero order at high; doesn't take much to get out of therapeutic range

Use: Partial seizures, generalized tonic-clonic seizures (primary and secondary); NOT effective for absence

Interactions: Metab by liver, warfarin competes, will increase significantly if combined with phenytoin (starts bleeding in hospital in question)

Tox:Gingival hyperplasia, pregnancy category D

Other Drugs: Fosphenytoin (Cerebyx) = soluble prodrug for injection

Anticonvulsant

Mechanism: Enhance GABA activity, increasing inhibition of glutamate

Uses: Partial seizures, generalized tonic clonic

Tox: CNS and resp. depression, pregnancy category D

Other Drugs:Primidone (Mysoline);

Levetiracetam (Keppra)- myoclonic seizures

Lamotrigine (Lamictal) - absence,partial seizures, bipolar stevens-johnson syndrome; preg cat. C

Topiramate (Topamax) - absence, migraine prophylaxis, weight loss, alcoholism; preg cat. C

Gabapentin (Neurontin)- adjunct for partial and generalized tonic clonic seizures; neuropathic pain use; causes sleepiness

Vigabatrin (Sabril)- visual field problems/ retinal damage

Tiagabine (Gabatril)- 

Anticonvulsant

Mechanism: Block thalamic, low-threshold (T-type) Ca+2 current; "pacemaker" of thalamic neurons in abscence seirzure; 

Uses: DOC FOR ABSENCE SEIZURES

Tox: GI irritant, Preg. cat. C

Anticonvulsant

Mechanism: Blocks Na+ Channel, holds channel in inactive state longer; inhibits rapidly firing neurons, little effect on normal neurons

Use: Partial seizures, generalized tonic-clonic seizures, trigeminal neuralgia, bipolar

Tox: GI upset, idiosyncratic blood dyscrasias (AGRANULOCYTOSIS), HLA-B*1502