Narcolepsy

Narcolepsy is characterized by excessive daytime sleepiness that is typically associated with cataplexy and other rapid-eye-movement (REM) sleep phenomena such as sleep paralysis and hypnagogic hallucinations. Sleepiness, the main symptom in narcolepsy, leads to repeated daily episodes of naps or lapses into sleep of short duration. 

The other main symptom, cataplexy, is characterized by a sudden loss of bilateral muscle tone provoked by strong emotion, typically by laughter. Cataplexy is usually of short duration, ranging from a few seconds to several minutes, and recovery is fast and complete. 

The majority of patients need medication for the two main symptoms. Drugs with CNS-stimulating effects, mostly of the amphetamine type, are used to alleviate excessive sleepiness and sleep attacks. The resulting increased level of vigilance also decreases or abolishes cataplexy in a number of patients. If this is not achieved, tricyclic antidepressants, in the hrst instance, and selective serotonin (5-hydroxytryptamine 5-HT) reuptake inhibitors, in the second instance, can be used to control cataplexy and other rapid-eye-movement sleep-related symptoms. 

Stimulatory drugs used in the Anticataplectic drugs used in the treatment 

Natamycin is an ophthalmic antifungal agent, which binds to fungal cell membrane, altering membrane permeability and depleting essential cellular constituents. A polyene mac-rolide antibiotic (instill 1 drop of 5% solution in conjunctival sac), natamycin is used in conjunctivitis, keratitis, and blepharitis caused by susceptible fungi. 

Some stimulants are approved for treatment of narcolepsy. Stimulants mainly improve excessive daytime sleepiness, and the effects may be dose related (Mitler et al. 1990). However, cataplexy usually does not respond to stimulants (Hyman et al. 1995). Stimulants are often administered in divided daily doses, and doses are often titrated weekly on the basis of clinical response. 

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Pemoline [2152-34-3] (24), stmcturally dissimilar to amphetamine or methylphenidate, appears to share the CNS-stimulating properties. As a consequence, pemoline is employed in the treatment of ADHD and of narcolepsy. There are several other compounds that are stmcturally related to amphetamines, although not as potent and, presumably, without as much abuse potential. These compounds also have anorexic effects and are used to treat obesity. Some of the compounds available are phentermine [122-09-8] fenfluramine [458-24-2] and an agent that is available over-the-counter, phenylpropanolamine [1483815-4] (26). 

Knockout mice exhibit narcolepsy. hMice under chronic high fat diet. 

Zeitzer JM, Nishino S, Mignot E (2006) The neurobiology of hypocretins (orexins), narcolepsy and related therapeutic interventions. Trends Pharmacol Sci 27 368-74... 

The mode of action of modafinil, a new arousal-promoting compound used in the treatment of sleepiness associated with narcolepsy, is not fully understood. 

NARCOLEPSY The nurse observes the patient with narcolepsy during daytime hours. If periods of sleep are noted, the nurse records the time of day they occur and their length. 

Narcolepsy Keep a record of the number of times per day that periods of sleepiness occur, and bring this record to each visit to the primary healtii care provider or clinic. 

Mr. Trent has narcolepsy and is prescribed amphetamine 10 mgfl. Develop questions you would ask Mr. Trent when he returns to the clinic for evaluation after 1 month of therapy. 

Stimulants induce both tolerance and sensitization to their behavioral effects. Tolerance develops to the anorectic and euphoric effects of stimulants (Schuster 1981) however, chronic intermittent use of low doses of stimulants delays the development of tolerance. With the doses commonly used in clinical practice, patients treated for narcolepsy or for depressive or apathetic states find that the stimulant properties usually persist without development of tolerance however, the persistence of antidepressant effects remains a matter of controversy. Sensitization has been linked to the development of amphetamine-induced psychosis (Yui et al. 1999). Sensitization to the induction of psychosis is suggested because psychosis is induced by progressively lower doses and shorter periods of consumption of amphetamine following repeated use over time (Sato 1986). Sensitization for amphetamine-induced psychosis may persist despite long periods of abstinence. 

Scrima L, Hartman PG, Johnson EH, et al The effects of gamma-hydroxybutyrate on the sleep of narcolepsy patients a double blind study. Sleep 13 479 90, 1990 Series F, Series 1, Cormier Y Effects of enhancing slow-wave sleep by gamma-hydroxybutyrate on obstructive sleep apnea. Am Rev Respir Dis 143 1378-1383, 1992 Shannon M Methylenedioxymethamphetamine (MDMA, ecstasy ). Pediatr Emerg Care 16 377-380, 2000... 

Drugs with no therapeutic use (cannabis, LSD) and so are not prescribed Drugs with medical use — heroin and morphine for pain relief, amphetamine for narcolepsy and cocaine... 

Amphetamines (speed sulph, sulphate, uppers, wake-ups, billy whizz, whizz, whites, base) are synthetic stimulants which as medicines have been formed into a variety of tablets. Their current medical use is very limited and in fact only dexamphetamine sulphate, Dexedrine, is now available for use solely in the treatment of narcolepsy. The only other amphetamine available for medical use is methylphenidate (Ritalin) for the treatment of attention deficit syndrome in children. As a street drug, amphetamine usually comes as a white, grey, yellowish or pinky powder. The purity rate of street powders is less than 10%, the rest being made up of milder stimulants such as caffeine, other drugs such as paracetamol or substances like glucose, dried baby milk, flour or talcum powder. 

Describe the mechanisms of the sleep disorders covered in this chapter, including insomnia, narcolepsy, restless-legs syndrome, obstructive sleep apnea, and parasomnias. 

Treatment of excessive daytime sleepiness in narcolepsy and other sleep disorders may require the use of sustained- and immediate-release stimulants to effectively promote wakefulness throughout the day and at key times that require alertness. 

Although difficult to estimate, the prevalence of narcolepsy is between 0.03% and 0.06%.7 Significant differences have been reported for various ethnic groups. Narcolepsy has a higher prevalence in the Japanese and a lower prevalence in the Israeli populations.8,9 Cataplexy is not required for diagnosis however, between 50% and 80% of patients with narcolepsy have accompanying cataplexy.10... 

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