Antihistamines anxiety with

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. 

Hydroxyzine hydrochloride Atarax, Vistarit) is the antihistamine with the greatest use in the treatment of anxiety. It is often used to reduce the anxiety that is associated with anesthesia and surgery. It also produces sedation, dries mucous membranes (via an anticholinergic mechanism), and has antiemetic activity. A more extensive discussion of the pharmacology of the Hj-receptor antagonists is found in Chapter 38. 

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. 

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). 

For those with a history of substance abuse or intolerance to benzodiazepines and the elderly, caution must be used in controlling anxiety. In these cases, benzodiazepines may exacerbate other conditions. Preliminary reports suggest that antipsychotics such as quetiapine may alleviate symptoms of anxiety. Other strategies include use of antihistamines such as hydroxyzine and diphenhydramine. 

Despite very limited efficacy in most anxious patients, b-blockers may be useful for highly somatic individuals, such as those with performance anxiety. Antihistamines... 

Because oxycodone may intensify the effects of other drugs that cause drowsiness, it should not be taken with antidepressants, antihistamines, anti-anxiety drugs, seizure medications, sedatives, sleeping pills, or muscle relaxants, except under the supervision of a doctor. Patients who may be prescribed oxycodone should tell their doctor if they are taking any of these medications. 

The barbiturates and meprobamate have been entirely superseded by the benzodiazepines and because of their low benefit-to-risk ratio (dependence producing, lethality in overdose, potent sedative effects) they should never be used as anxiolytics. Despite their popularity as short-term sedatives, antihistamines are ineffective anxiolytics, while the use of sedative antidepressants such as amitriptyline should be limited to the treatment of patients with symptoms of both anxiety and depression due to their limited efficacy and the poor patient compliance associated with their adverse effects. However, patients with panic disorder do appear to show a beneficial response to antidepressants (see Chapter 6). A similar argument... 

Hydroxyzine [hye DROX i zeen] is an antihistamine with antiemetic activity. It has a low tendency for habituation thus it is useful for patients with anxiety, who have a history of drug abuse. It is also often used for sedation prior to dental procedures or surgery. 

Corned answer = B. The anxiolytic properties of benzodiazepines, such as lorazepam, make them the drugs of choice in treating the anxiety and agitation of cocaine withdrawal. Lorazepam also has hypnotic properties. Phenobaibital has hypnotic properties but if s anxiolytic properties are inferior to those of the benzodiazepines. Cocaine itself could countered the agitation of withdrawal but its use would not be proper therapy. Hydroxyzine, an antihistaminic, is effective as an hypnotic and is sometimes used to deal with anxiety especially if emesis is a problem. Fluoxetine is an antidepressant with no immediate effects on anxiety. 

Most side effects, such as transient yellowing of the skin and conjunctiva, a fluorescent cast to the mane, and the warm flush or early nausea occurring within 30 seconds of injection, can be explained to the patient before the procedure. Some practitioners advocate prophylaxis for nausea and vomiting, including administration of prochlorperazine, promethazine, or trimethoben-zamide, although there is no conclusive evidence for their benefit to patients. For patients likely to develop mticaria, premedication with systemic antihistamines is possible. Benzodiazepines, such as diazepam, may also be useful to control anxiety. 

Although it has been thought to have relatively little stimulant effect on the central nervous system, phenylpropanolamine can produce restlessness, anxiety, insomnia, and tremor its central stimulant effects are in practice often masked by manufacturers practice of combining it with an antihistamine. 

Diazepam is used primarily in the treatment of mental anxiety. In addition, it acts as a muscle relaxant for a variety of medical conditions. It may also be used as a sedative-hypnotic and anticonvulsant (e.g., for status epilepticus and drug-induced seizures). Diazepam may also be used to alleviate some of the symptoms associated with the following cholinesterase poisoning, substance abuse withdrawal, antihistamine overdose. Black Widow spider envenomation, and chloroquine overdose. As an anesthetic, diazepam may be used alone or in combination with other drugs for conscious sedation. 

Sedation and sleep promotion can be achieved with drugs that are not classed as sedatives or hypnotics, including antihistamines (e.g., hydroxyzine) and opioid analgesics. Tricyclic antidepressants (TCAs) have been used in anxiety characterized by panic and/or phobias, and more recently the selective serotonin reuptake inhibitors (SSRIs) have been used. Propranolol has efficacy in performance anxiety and social phobias. 

The antihistamine hydroxyzine is an effective antianxiety agent, but only at doses (-400 mg/day) that produce marked sedation (see Chapter 24). Propranolol and metoprolol, lipophilic fi adrenergic receptor antagonists that enter the CNS, can reduce the autonomic symptoms (nervousness and muscle tremor) associated with specific situational or social phobias but do not appear to be effective in generalized anxiety or panic disorder (see Chapter 10). Similarly, other antiadrener-gic agents, including clonidine, may modify autonomic expression of anxiety but are not demonstrably usfful in the treatment of severe anxiety disorders. 

The cannabinoids act on the cerebral cortex and have the same side effects and adverse reactions as antihistamines and anticholinergic. These include drowsiness, dry mouth, blurred vision, tachycardia, and constipation. Caimabinoids include dronabinol and nabilone. These drugs should not be administered to glaucoma patients because they dilate the pupils (mydriasis). They are contraindicated for use in patients with psychiatric disorders and also used as an appetite stimulant for patients with AIDS. Side effects include mood changes, euphoria, drowsiness, dizziness, headaches, depersonalization, nightmares, confusion, incoordination, memoiy lapse, dry mouth, orthostatic hypotension, hypertension, and tachycardia. Less common symptoms include depression, anxiety, and manic psychosis. 

Your judgement in choosing antidepressants will only come with experience. Use the BNF/Maudsley Prescribing Guidelines (MPG) and call your pharmacist or consultant for advice. People often request anxiolytics, but these should be avoided where possible anxiety usually improves as the depression lifts, and may improve with sleep hygiene or relaxation techniques. If there s prominent anxiety or insomnia - whether primary or due to medication side effects - you might consider a short-term benzodiazepine or sedative antihistamine. 

---