Drugs Related To The Central Nervous System

Muscle relaxants Muscle relaxants (also called skeletal muscle relaxants) are a diverse group of medicines that have the ability to relax or reduce tension in muscle. Some (such as baclofen, methocarbamol, and tizanidine) work in the brain or spinal cord to block over-excited neuronal (nerve) pathways. Others (such as dantrolene and botulinum toxin) act directly on muscle. Cannabis extract is thought to have a dual effect. Muscle relaxants treat two main conditions: spasticity (stiff, rigid muscles) caused by conditions such as cerebral palsy, multiple sclerosis, and stroke; or muscle spasms which are typically temporary and associated with conditions such as tension headache, low back pain, or fibromyalgia. Only three muscle relaxants - baclofen, dantrolene, and tizanidine are FDA approved to treat spasticity; however, six (carisoprodol, chlorzoxazone, cyclobenzaprine, metaxalone, methocarbamol, and orphenadrine) are approved to treat muscle spasm. Botulinum toxin is only appro...

Anxiolytics, sedatives, and hypnotics Anxiolytics, sedatives and hypnotics are medicines that work on the central nervous system to relieve anxiety, aid sleep, or have a calming effect. The benzodiazepines are the main class of drugs that fit into this category . Although there are more than twenty benzodiazepine derivatives, only certain ones have been approved to treat anxiety (eg, alprazolam, clonazepam, diazepam, and lorazepam ), sleeplessness (insomnia) (eg, estazolam, flurazepam, quazepam, temazepam and triazolam), or panic disorder (eg, alprazolam). Barbiturates are an older class of medicine that used to be used for these indications as well; however, barbiturates have a narrow therapeutic index (window of effectiveness before toxicity occurs), and are more likely to cause respiratory depression, coma and death, and are very rarely used nowadays. The main issue with use of benzodiazepines is dependence. Benzodiazepines differ in their propensity to cause sedation and in th...

Antiparkinson agents Antiparkinson agents aim to replace dopamine either by drugs that release dopamine or those that mimic the action of dopamine . Parkinson's disease is a degenerative disorder of movement that occurs due to dopamine deficiency in the basal ganglia. Antiparkinson agents attempt to replace dopamine and treat or halt the symptoms such as tremor, hypokinesia, and so on. Anticholinergic antiparkinson agents Anticholinergic antiparkinson agents or acetylcholine antagonists block the muscarinic acetylcholine receptors and cholinergic nerve activity.  Activation of muscarinic receptors has an excitatory effect, opposite to that of dopaminergic activation, so suppression of the effects of acetylcholine compensates for a lack of dopamine in Parkinson's disease.  Acetylcholine and dopamine have to be carefully balanced for proper body movement. Anticholinergic agents create a better balance between acetylcholine and dopamine. Anticholinergic agents are...

Antiemetic/ antivertigo agents Vomiting is controlled by the vomiting center in the medulla. Vomiting center is activated by either one of four trigger zones: chemoreceptor trigger zone, vestibular nuclei, cerebral cortex and gastrointestinal tract. Vomiting center is controlled by serotonin (5-HT3), muscarinic and histamine (H1) receptors. Chemoreceptor trigger zone is sensitive to chemical stimuli, such as opioids and cytotoxic drugs. It is under the control of dopamine, serotonin (5-HT3) and opioid receptors. Vestibular nuclei is controlled by muscarinic and histamine (H1) receptors. This is activated in vertigo or motion sickness. Cerebral cortex activates vomiting from smell, thought and so on. Gastrointestinal tract has serotonin (5-HT3) receptors, which are affected by chemotherapeutic drugs. Different classes of drugs work on different receptors and act as antiemetics and antivertigo agents. 5HT3 receptor antagonists 5-HT3 receptor antagonists (also called serot...

What are Anorexiants? Anorexiants are drugs that act on the brain to suppress appetite. They have a stimulant effect on the hypothalamic and limbic regions, which control satiety. Anorexiants are used as therapy for obesity. Phendimetrazine Phendimetrazine is a sympathomimetic amine, which is similar to an amphetamine. It is also known as an "anorectic" or "anorexigenic" drug. Phendimetrazine stimulates the central nervous system (nerves and brain), which increases your heart rate and blood pressure and decreases your appetite. Phendimetrazine is used as a short-term supplement to diet and exercise in the treatment of obesity.   Phendimetrazine may cause blurred vision or impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert and able to see clearly. Phendimetrazine may be habit-forming and should be used only by the person it was prescribed for. Keep the medication in a secure place where others cannot get t...

What are Anticonvulsants? Anticonvulsants (antiepileptics or AEDs) helps to normalise the way nerve impulses travel along the nerve cells which helps prevent or treat seizures. When the brain is working normally the nerve cells talk to each other using controlled electrical signals from one nerve cell to another. This tells the body to do everything it needs or wants to do. During a seizure there is a change in the level of nerve cell electrical signals from a normal level to an excessive or abnormal amount of nerve signals. This increased nerve activity is responsible for the signs and symptoms of a seizure. What causes the change is nerve impulses can be the result of an injury to part of the brain, stroke, brain tumor, genetic causes, metabolic problems or toxicity issues. Anticonvulsants can also be used to treat nerve pain and bipolar disorder. How they work? Anticonvulsants keep the nerve cell impulses to a normal level so they don’t become excessive and uncontrolled, w...