hypnotic

For the state of mind see Hypnosis.

Hypnotic (also called soporific) drugs are a class of psychoactives whose primary function is to induce sleep^[1] and to be used in the treatment of insomnia and in surgical anesthesia. Because drugs in this class generally produce dose-dependent effects, ranging from anxiolysis to production of unconsciousness, they are often referred to collectively as sedative-hypnotic drugs.^[2] Often the treatment of insomnia will not begin with drugs at all. Since many hypnotic drugs are habit-forming, a physician will usually recommend alternative sleeping patterns, sleep hygiene, and exercise before prescribing medication for sleep, due to a large number of factors known to disturb the human sleep pattern. Hypnotic medication when prescribed should be used for the shortest period of time.^[3] The benzodiazepine and nonbenzodiazepine hypnotic medications also have a number of side effects such as daytime fatigue, motor vehicle crashes, cognitive impairments and falls and fractures. Elderly people are more sensitive to these side effects and a meta analysis found that the risks generally outweigh any marginal benefits of hypnotics in the elderly.^[4] A review of the literature regarding benzodiazepine hypnotic as well as Z drugs concluded that these drugs caused an unjustifiable risk to the individual and to public health and lack evidence of long term effectiveness due to tolerance. The risks include dependence, accidents and other adverse effects. Gradual discontinuation of hypnotics leads to improved health without worsening of sleep. Preferably they should be prescribed for only a few days at the lowest effective dose and avoided altogether wherever possible in the elderly.^[5]

Benzodiazepines

Benzodiazepines are the most well known and most frequently prescribed hypnotic medication presently. However, their use in recent years is being increasingly replaced by newer nonbenzodiazepine hypnotic drugs and the hormone melatonin, which in North America is called a "supplement". They are effective in the short term but with long term use beyond 1 – 2 weeks tolerance to their hypnotic effects develops thus making them ineffective for long term use. They are also a cause of hospital admissions especially in the elderly who are more sensitive to their effects. Additionally, benzodiazepine withdrawal syndrome can develop upon their discontinuation. This is characterized by rebound insomnia, anxiety, confusion, disorientation, insomnia, and perceptual disturbances. Prescription hypnotics are therefore best limited to short term use to avoid tolerance, drug dependence and the adverse effects of long term use.^[6]

Benzodiazepines tend to exert their hypnotic effects at high dosage compared to the more moderate dosage needed for anxiolytic effects to be felt.^[7] The downside of the hypnotic properties of benzodiazepines is that they actually worsen the sleep architecture and thus the quality of sleep.^[8] They are also associated with an increased risk of road traffic accidents.^[9]

Nonbenzodiazepines

Nonbenzodiazepines have demonstrated efficacy in treating some sleep disorders. There is also limited evidence that suggests that tolerance to nonbenzodiazepines is slower to develop than with benzodiazepines. However, data are limited so no conclusions can be drawn. Data are also limited with regard to long term effects of nonbenzodiazepines; further research into the safety and long term effectiveness of nonbenzodiazepines has been recommended in a review of the literature.^[10]

Examples

These drugs include:

• Barbiturates
• Opioids
• Benzodiazepines
  • Estazolam
  • Flunitrazepam
  • Lormetazepam
  • Midazolam
  • Nitrazepam
  • Quazepam
  • Temazepam
  • Triazolam
• Nonbenzodiazepines
  • Zolpidem
  • Zaleplon
  • Zopiclone
  • Eszopiclone
• Antihistamines
  • Diphenhydramine
  • Doxylamine
  • Hydroxyzine
  • Promethazine
• Melatonin Agonists
  • Ramelteon
  • Melatonin
  • Tasimelteon
• gamma-hydroxybutyric acid (Xyrem)
• Methaqualone
• Glutethimide
• Chloral hydrate
• Ethchlorvynol
• Levomepromazine
• Chlormethiazole
• Diethyl ether
• Alcohol is also used as a hypnotic drug, though not medically. To quote the British National Formulary: "Alcohol is a poor hypnotic because its diuretic action interferes with sleep during the latter part of the night. Alcohol also disturbs sleep patterns, and so can worsen sleep disorders"

See also

• Insomnia

References