This group of drugs constitutes the major treatment for some of the most disturbed patients seen by psychiatrist. Anti psychotics drugs are mainly used to treat acute schizophrenic episodes and to prevent reemergence of psychotic syndrome in schizophrenic patients.
These compounds also are useful for other psychotic condition, including mania, psychotic disorder due to a general medical condition; substance induced psychotic disorder, and Tourette's Disorder.
Antipsychotic drugs produce a board range of side effects.
Atypical antipsychotic drugs
Two currently available antipsychotic drugs, Clozapine (chloral) and Risperidon are considered atypical because they produce little or no extrapyramidal side effects.
Clozapine differs from all other available antipsychotic drugs, which have their major effects -as antagonists of DA receptors, particularly D2 receptors. Clozapine has a high affinity for the serotonin type 2 (5-hydroxytryptamine [5-HT2]), and a-adrenergic, cholinergic (muscarinic), and histamine type 1 (Hl) receptors. Moreover clozapine's DA type 1 (D1) antagonist activity is much greater than its D2 antagonist activity.
The two most serious adverse effects associated with Clozapine use are agranulocytisis and seizures.
Risperidon is an antipsychotic drug with significant antagonist activity at the 5- HT2 receptor and at the D2 receptor. researchdata indicate that it may be more effective than currently available dopamine receptor antagonists at treating both the positive and the negative symptoms of schizophrenia. The studies used dosages ranging of 2-16 mg a day of Risperidon compared with a placebo and up to 20mg a day of haldol.
Risperidon use may be associated with anxiety, insomnia, somnolence, dizziness, constipation, nausea, dyspepsia, rhinitis, rash and tachycardia. Dose-related side effects include sedation, fatigue, accommodation disturbances, Orthostatic dizziness, weigh gain, diminished sexual desire and erectile dysfunction.
The tricyclic antidepressant Imipramine was discovered during clinical testing for antipsychotic drugs. The tricyclic and tetracycline antidepressants inhibit the neuronal reuptake of both NE and 5-HT, thus increasing the amount of these neurotransmitters in the synapse.
Two antidepressants that are sterilely and pharmacologically similar to the tricyclics are amoxapine (asendin) and maprotiline (ludiomil)
Amoxapine is an analogue of loxapine, a potent antipsychotic Drug. Amoxapine has clinically significant dopamine-blocking activity. Each 100mg of amoxapine is equivalent to about 0.5-1.Omg of Haloperidol in antipsychotic activity.
Maprotiline is the most selective inhibitor of Nereuptake. It is structurally and pharmacologically similar to desipramine, the second most selective NE blacker.
Fluoxetine has a half-life of up to 4-6 days and an active metabolic that has a half-life of up to 16 day
Sertraline is the most selective of the SSRIs, although the relevance of this property is not established. Sertraline also possesses some dopamine reuptake blocking activity.
Paroxetine exhibits the greatest potency in 5-HT reuptake inhibitions, but is not as selective as Sertraline. The clinical significance goes these distinctions are not known. Paroxetine has a half-life of 1 day and has no active metabolites.
Fluvoxamine is an SSRI that is not markedly different from other drugs of this class but that is approved only for the treatment of obsessive-compulsive disorder by the FDA.
Two Phenylpiperazines agents, trazodone and nefazodone, are unique among the antidepressant drugs in that they are potent antagonists of the 5-HT2receptor. They are, however, different in their profile of side effects.
- Trazodone-trazodone is a highly specific 5-HT reuptake blacker in vitro. Its therapeutic effects are due to its activity as a 5-HT reuptake inhibitor and a 5-HT2 antagonist.
- Nefazodone-although and analogue of trazodone, nefazodone has a distinct combination of pharmacological effects and as a consequence, a different side effect profile. Like trazodone, nefazodone is a potent antagonist of postsynaptic 5-HT2A receptors and an inhibitor of presynaptic 5 Htreuptake.
What's best for what ails you. How the top 6 stack up
You are in pain arid you want relief. But chemist shop shelves are packed with a confusing array of products. What's best for a tension headache, menstrual cramps or arthritis? Are all painkillers created equal? No, says Rob Hutchison, a pharmacy specialist in pain management at Presbyterian Hospital of Dallas. They all have different benefits, side effects and possible drug interactions.
For example, aspirin and ibuprofen help reduce inflammation but may cause stomach problems. Acetaminophen is easier on the stomach, but it doesn't halt inflammation - and it may cause liver damage if taken in high doses for several days.
Whichever pain reliever you choose, reading labels is key, says Jan Engle, past president of the American Pharmacists Association. The OTC drugs are meant for short-term use (no more than ten days without a doctor's OK). If you're pregnant, trying to conceive, breast-feeding or on prescription drugs, talk to your doctor or pharmacist before taking any medication. Here are answers to your pain-killer questions.
Similar of Antipsychotic Drugs