PSYCHIATRIC DRUGS
May be classified in various ways, including chemical structure, clinical effect, and pharmacologic mechanism.
CLASSIFICATION BY CLINICAL EFFECTS
Classification system that clinicians may find most practical and useful. It groups the drugs under the effects they appear to exert on the symptoms of certain disorders; however, most often, more than one category of disorders are targeted by the same class of medications. For example, antidepressants are widely used in the treatment of several conditions, including depression, anxiety, eating disorders, & OCD.
Serotonin-Norepinephrine Reuptake Inhibitors (SNRI)
work to increase both serotonergic and noradrenergic activity. SNRI's include Effexor-venlafaxine & Cymbalta-duloxetine. SNRI's are used to treat anxiety disorders and neuropathic pain.
Tricyclic Antidepressants (TCA)
Thought to exert a general inhibitory effect on the reuptake of all monoamine neurotransmitters, including norepinephrine, dopamine, and serotonin. Due to their many side effects and dietary restrictions, TCA's are typically only prescribed if SSRI's are ineffective. Commonly TCAs include Tofranil-imipramine & Anafranil-clomipramine.
Monoamine Oxidase Inhibitors (MAOI)
Inhibit the activity of monoamine oxidase, which breaks down monoamines and thereby increases serotonin, dopamine, and norepinephrine levels in the brain. Effective in the treatment of atypical depression. Because they cause more side effects and have more drug and dietary interactions than SSRIs and TCAs, they are typically reserved as last-option antidepressants. MAOIs brand-names include: Nardil-phenelzine, Parnate-tranylcypromine, and Emsam-selegiline.
ANTI-OBSESSIONAL
This is a useful sub-category of the main antidepressant list, emphasized because of their effects on obsessive thoughts via serotonergic action. It is mostly comprised of SSRIs and includes Prozac, Zoloft, Paxil, Luvox, Celexa, Lexapro, and also the TCA Anafrenil
MOOD STABILIZERS and ANTI-CONVULSANTS
This is a class of drugs commonly used to treat bipolar disorder. Anti-convulsants were traditionally manufactured for the treatment of epileptic seizures, but subsequently found useful also as mood stabilizers. Examples include: Eskalith and Lithonate (lithium carbonate), Symbiax (a synthesis of olanzapine and fluoxetine), Tegretol (carbamazepine), Trileptal (oxcarbazepine), Depakote (divalproex), Lamictal (lamotrigine), Topomax (topiramate), and Gabirtril (tiagabine).
PSYCHOSTIMULANTS
Widely used in the treatment of attention deficit disorders, this list includes Ritalin and Concerta (methylphenidate), Dexedrine (dextroamphetamine), and Adderall (d- and l- amphetamine).
ANTIPSYCHOTICS
These medications are mainly used to treat psychotic illness; they can also be used as adjuncts for depressive disorders when appropriate. This class can be further divided in low and high potency, as well as typical (traditional) and atypical (newer).
Low Potency antipsychotics
Low Potency only means that a higher dosage is needed for the desired effect, and does not have to do with side effects and sedative power. Low Potency antipsychotics are known to have significant side effects and sedative power.
Low Potency medications include:
Thorazine (chlorpromazine), Mellaril (thioridazine), Clozaril (Clozapine), and Seroquil (quietapine)
High Potency medications include:
Loxitane (loxapine), Stelazine (trifluoperazine), Prolixin (fluphenazine), Navane (thiothixene), Haldol (Haloperidol), Risperdal (risperidone), Zyprexa (olanzapine), and Abilify (aripiprazole)
ANTI-ANXIETY
This class of medications can be further divide into Benzodiazepines and Other Anti-Anxiety Agents. They are widely used to treat both anxiety and mood disorders, and can be adjuncts in antipsychotic regimes.
Benzodiazepines
Valium (diazepam), Librium (chlordiazepoxide), Klonopin (clonazepam), and Ativan (lorazepan)
Other anti-anxiety agents
BuSpar (buspirone), Neurontin (gabapentin), and the beta-blocker Inderol (propanolol)
HYPNOTICS
This class includes mostly "sleepers," such as Dalmane (flurazepam), Doral (quazepam), Restoril (temazepan), the newer Ambien (zolpidem), Sonata (zaleplan), and Lunesta (eszoplclone), as well as the antihistaminic Benadryl (diphenhydramine) for its sedative side effects.
NATURAL/HERBAL MEDICATIONS
St. John's Wort: an herbal product shown to treat depression & anxiety
SAM-e :shown effective for depression
Omega-3: shown effective for depression & bipolar disorder
Drug Formulation
The pharmaceutical process by which certain chemical substances, including the active agent, are synthesized to produce the final drug.
Drug Description
Mainly the listing of chemical ingredients, with their dosages and formulas, that make up a specific drug.
Tricyclics are best for treating
vegetative symptoms i.e., appetite and sleep issues, psychomotor retardation
TCAs are used to treat depression, anxiety, OCD, & neuropathic pain. may be helpful for agoraphobia
side effects of tricyclics
dry mouth, constipation, urinary retention, blurred vision, and nasal congestion
MAOI's are best for treating
atypical depression: increased, hypersomnia, mood reactivity, rejection sensitivity, accompanying anxiety
Side effects of MAOI's
hypotension, dizziness, dry mouth, nausea, weight gain, blurred vision Most serious is a hypertensive crisis if taken with other drugs or food with the amino-acid tyramine
Side effects of lithium
gastric distress, weight gain, tremor, fatigue, confusion 35% will have tremor in fingers. It can be toxic or deadly.
What are side effects of antipsychotics
anticholinergic: dry mouth, blurred vision, tachycardia, gastric
Extrapyramidal: parkinsonism, akathisia, dystonia, tardive dyskinesia
akathisia
motor restlessness such as fidgeting, rocking, or pacing due to the neuromuscular or neurologic adverse effects associated with the use of antipsychotics
dystonia
"a syndrome of sustained muscle contractions, frequently causing twisting and repetitive movements or abnormal postures." Differences in the extent & severity of muscle and frequency of symptom involvement range from intermittent contraction limited to a single body region to generalized dystonia involving the limbs & axial muscles. Features such as age of onset and presumed etiology play a tremendous role in prognosis & treatment. A younger age of onset associated with a more generalized and severe course in primary dystonias.
ataxia
Inability to coordinate muscle activity during voluntary movements, resulting in shaky/tremor-like movements
BENZODIAZEPINES
Anti anxiety drugs which include Diazepam (Valium), alprozolam (Xanax), Clonozepam (Klonopin), Lorazepam (Ativan) they are used to treat GAD, panic, insomnia, alcohol withdrawal, epilepsy
Benzodiazepine withdrawal
is similar to alcohol withdrawal syndrome and barbiturate withdrawal syndrome and can in severe cases provoke life threatening withdrawal symptoms such as seizures; protracted withdrawal symptoms include anxiety, irritability, insomnia and sensory disturbances.
Bioavailability
The portion of a drug that reaches the blood, or the physiological availability of a given amount of a drug, versus its chemical potency. It is a main principle of pharmacokinetics.
Pharmacokinetics (PK)
Is both a biochemical process and a branch of pharmacology; as a process, it can be defined as, "the change over time of the blood levels of a drug following administration." As a field of study, it is concerned with "how the body absorbs, distributes, breaks down, & eliminate drugs. PK involves the use and application of chemical & mathematical formulas.
Purposes of Pharmacokinetics (PK)
1. study the course of a drug over time, in relation to its absorption by the body, distribution, metabolism and excretion.
2. study how these four processes relate to the time course and the intensity of both therapeutic and side effects of the drug.
Difference between Pharmacokinetics (PK) & Pharmacodynamics (PD)
PK entails what the body does to the drug, while PD is what the drug does to the body
Pharmacometrics (PM)
Involves quantitative analysis and interpretation in relation to the effects of drugs in preclinical and clinical trials. Quantitative analysis and interpretation based on PK and PD
The "catecholamine hypothesis" predicts that drugs which _______________ will alleviate depression.
maintain or increase norepinephrine levels