Insomnia antihistamines

The short-acting clomethia2ole [533-45-9] (1), sometimes used as therapy for sleep disorders ia older patients, shares with barbiturates a risk of overdose and dependence. Antihistamines, such as hydroxy2iae [68-88-2] (2), are also sometimes used as mild sedatives (see HiSTAMlNES AND HISTAMINE antagonists). Antidepressants and antipsychotics which have sedative effects are used to treat insomnia when the sleep disorder is a symptom of some underlyiag psychiatric disorder. 

FDA for chronic use up to 6 months.33 Although not first line-agents for insomnia, sedating antihistamines are prescribed commonly, and the number of prescriptions has increased dramatically over the last 20 years.34 These and other therapies, detailed below, are used to treat insomnia. 

Antihistamines such as diphenhydramine are known for their sedating properties and are frequently used over-the-counter medications (usual doses 25-50 mg) for difficulty sleeping. Diphenhydramine is approved by the FDA for the treatment of insomnia and can be effective at reducing sleep latency and increasing sleep time.43 However, diphenhydramine produces undesirable anticholinergic effects and carryover sedation that limit its use. As with TCAs and BZDRAs, diphenhydramine should be used with caution in the elderly. Valerian root is an herbal sleep remedy that has inconsistent effects on sleep but may reduce sleep latency and efficiency at commonly used doses of 400 to 900 mg valerian extract. Ramelteon, a new melatonin receptor agonist, is indicated for insomnia characterized by difficulty with sleep onset. The recommended dose is 8 mg at bedtime. Ramelteon is not a controlled substance and thus may be a viable option for patients with a history of substance abuse. 

Medications for symptomatic relief from vertigo consist of antiemetics, benzodiazepines and antihistamines. They are all mostly aimed at the psychological consequences of dizziness and can all have highly unfavourable side effects, for example, sedation, anticholinergic effects and insomnia. The psychological consequences of dizziness in elderly should rather be treated with information about the condition, supportive help actions and increased social activities, than with drugs. 

Antihistamines. After alcohol, antihistamines are the most commonly self-administered sleep medications. Foremost among these is diphenhydramine (Benadryl), which is also available as a component in a variety of over-the-counter nighttime medications including Tylenol PM and Excedrin PM. Prescription antihistamines like hydroxyzine (Vistaril, Atarax) are also occasionally used to treat insomnia. Finally, it is the antihistamine effect of some antidepressants and anti-psychotics that contribute to their utility as sedative-hypnotics. 

With long-term use, the most problematic side effect is weight gain. However, many antihistamines including diphenhydramine also possess potent anticholinergic effects. This can cause dry mouth, blurred vision, constipation, confusion, and urinary retention. Because anticholinergic effects are especially problematic for the elderly, we advise against the routine use of antihistamines to treat elderly patients with insomnia. 

Medications that enhance norepinephrine activity are used to treat depression and ADHD. Boosting norepinephrine can also produce numerous side effects including nervousness and anxiety, insomnia, and loss of appetite. With mirtazapine and the TCAs, these side effects are usually not a problem because these antidepressants also block histamine receptors. Their antihistamine effects promote increased appetite and drowsiness that tend to offset the side effects that might be experienced from increased norepinephrine activity. 

Bupropion should not be administered with sedating antihistamines because of the increased risk of seizures. Bupropion is used for smoking cessation therapy and may cause insomnia as a side-effect. Patients are advised to avoid taking bupropion dose at bedtime. 

Flurazepam (Dalmane) [C-IV] [Sedative/Hypnotic/ Benzodiazepine] Uses Insomnia Action Benzodiazepine Dose Adults Beds >15 y. 15-30 mg PO qhs PRN X in elderly Caution [X, /-] Elderly, low albumin, hepatic impair Contra NAG PRG Disp Caps SE Hangover d/t accumulation of metabolites, apnea, anaphylaxis, angioedema, amnesia Interactions T CNS depression W/ antidepressants, antihistamines, opioids, EtOH T effects OF digoxin, phenytoin T effects W/ cimetidine, disulfiram, fluoxetine, iso-niazid, ketoconazole, metoprolol, OCPs, propranolol, SSRIs, valproic acid. 

Quazepam (Doral) [C IV] [Sedative/Hypnotic/ Benzodiazepine] Uses Insomnia Action Benzodiazepine Dose 7.5-15 mg PO hs PRN i in elderly hqjatic failure Caution [X, /-] NA glaucoma Contra PRG, sleep apnea Disp Tabs SE Sedation, hangovCT, somnolence, resp depression Interactions T Effects W/ azole antifungals, cimetidine, digoxin, disulfiram, INH, levodopa, macrolides, neuroleptics, phenytoin, quinolones, SSRIs, verapamil, grapefruit juice, EtOH effects W/carbamazepine, rifampin, rifabutin, tobacco EMS Use caution w/ other benzodiazepines, antihistamines, opioids and verapamil, can T CNS depression concurrent EtOH and grapefruit juice use T CNS depression OD May cause profound CNS depression, confusion, bradycardia, hypotension, and altered reflexes flumazenil can be used as antidote activated charcoal may be effective... 

In the treatment of children and adolescents with anxiety disorders clinicians have a wide variety of pharmacologic options beyond the antidepressants (Shader and Greenblatt, 1995 Lydiard et ah, 1996 Riddle et ah, 1999). The benzodiazepines (BZs), with their favorable safety profile and quick onset of action, are attractive alternatives for the treatment of acute anxiety. While the clinical effectiveness of buspirone has not been proven in children, buspirone is used alone or in combination with other drugs in the treatment of anxiety disorders. The antihistamines are often used to treat insomnia and may reduce acute mild agitation. Zolpidem (Ambien) is occasionally used for its sedative properties. This chapter reviews the structure, proposed mechanisms of action, pharmacodynamic principles, and pharmacokinetic principles of these drugs. 

In the CNS, the histamine blockade leads to diminished alertness, slowed reaction times, and somnolence. The antihistamines should only be used as sedatives for a brief period of time because most people develop tolerance to the sedative properties within 1 week (Peggs et ah, 1995). Occasionally a patient may become restless, nervous, and develop insomnia. 

Antihistamines have been used for several decades in the treatment of anxiety in children (Tader, 1988). Prescription data show that antihistamines are widely used in pediatric psychiatric practices (Zito et ah, 2000). Diphenhydramine and hydroxyzine have been reported to modify anxiety symptoms in children with various psychiatric disorders. They are mainly used as a sedative in patients with insomnia. Occasionally they are used for mild acute agitation (AACAP, 1997). 

Sleep aids Diphenhydramine, 25-50 mg at bedtime Nytol, Simply Sleep, Sominex, various generic Diphenhydramine and doxylamine are antihistamines with well-documented CNS depressant effects. Because insomnia may be indicative of a serious underlying condition requiring medical attention, patients should consult a physician if insomnia persists continuously for longer than 2 weeks. 

So how is insomnia treated Most commonly, people self-medicate their insomnia with over-the-counter medications such as Tylenol PM , Sominex , Unisom , or other drugs such as antihistamines (discussed in Chapter 3). Other people try natural remedies such as melatonin (see Chapter 4). When such medications don t work, people often ask their doctor for a prescription sleep aid, which is usually a type of medication called a benzodiazepine such as Halcion or a related type of drug such as Ambien or Sonata (see Chapter 6 for more on these types of drugs). 

There are also numerous antidepressants that have sedative-hypnotic properties (Table 8—4). Some of these antidepressants are sedating owing to anticholinergic-antihistaminic actions. Not surprisingly, the tricyclic antidepressants (TCAs) can therefore be useful hypnotics to induce sleep in some patients. Thus, skillful use of a TCA in a depressed patient with insomnia can turn the liability of unwanted sedation into the asset of relief of insomnia if the TCA is given at bedtime. This property, as discussed in Chapter 6, has nothing to do, however, with the reason that TCAs are antidepressants (shown in Figs. 6—15 and 6—16). 

Antihistamines. Because of their sedating effects, antihistamines are sometimes used to treat insomnia. These drugs include diphenhydramine (Benadryl), an over-the-counter medication, and the prescription drugs hydroxizine (Atarax, Vistaril) and promethazine (Phen-ergan). Tylenol PM and many similar agents combine a pain medication with an antihistamine. 

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