Antihistamines dosing

Epinastine (Elestat) [Antihistamine] Uses Itching w/ allergic conjunctivitis Action Antihistamine Dose 1 gtt bid Caution [C, /-] Disp Soln SE Burning, folliculosis, hyperemia, pruritus, URI, HA, rhinitis, sinusitis, cough, pharyngitis EMS None OD Unlikely... 

The toxicity of astemizole also appears to be remarkably low. An acute toxicity study in rats found that at 25,000 times the antihistaminic dose (2,560 mg/kg) the drug produced some transient sedation but no lethality up to 2 weeks after administration—an extreme safety margin. This raises the possibility that antihistamines may have intrinsic antiasthmatic activity, but at such doses that the toxicity of the first-generation drugs precluded such a use at safe doses. 

Clemastine Fumarafe (Tavist, Dayhist, Antihist-1) [OTC] [Antihistamine] Uses Allergic rhinitis Sxs of urticaria Action Antihistamine Dose Adults Peds. >12 y 1.34 mg bid to 2.68 mg dd max 8.04 mg/d <6 y 0.335-0.67 mg/d into (max 1.34 mg/d) 2-3 d. 6-12 y 0.67-1.34 mg bid (max 4.02 /d) Caution [C, M] BOO do not take w/ MAOI Contra NAG Disp Tabs, syrup SE Drowsiness, dyscoordinadon, epigastric distress, urinary retendon Interactions T Effects V/ CNS depressants, MAOIs, EtOH i effects OF heparin, sulfonylureas EMS Use odier CNS depressants w/ caudon concuirent EtOH use can T CNS effects T risk of photosensidvity Rxns OD May cause CNS... 

Comparative studies European guidelines have recommended increased antihistamine doses of up to fourfold in patients with resistant urticaria [25 ], a recommendation that has been supported by a dose-escalation study that compared levocetirizine and desloratadine in such patients [26 ]. The effects of rupatadine at four times the recommended dose (40 mg) on platelet-activating factor (PAF) and histamine-induced cutaneous wheal and flare responses have been assessed in six healthy men [27. Rupatadine suppressed wheal and flare responses induced by both mediators for up to 72 hours after dosing. All of the subjects reported mild somnolence within 1-3 hours of taking rupatadine. 

This compound has antihistaminic activity and is usehil in the therapy of motion sickness. It may also be effective in the control of post-operative nausea and vomiting. It is classified as FDA Category B for Pregnancy, ie, no demonstrated risks shown in animal studies however, no controlled trials in pregnant women. Large doses may cause drowsiness and dry mouth owing to decreased secretion of saUva. 

Clinically Efficacy. It is evident from the mechanism of action of antihistamines and the etiology of allergic diseases that antihistamines in no sense achieve a cure of the patient s allergy. After the adrninistration of a therapeutic dose, a temporal blockade of the effects of histamine is obtained. Whereas classical antihistamines needed at least twice daily adrninistration, for most of the more recently introduced agents adrninistration once daily is sufficient. 

Zipeprol [34758-83-3] (58) is another European antitussive with a wide range of pharmacological effects, including antispasmodic, antihistaminic, and local anesthetic activities (85,86). It has been reported that zipeprol has been abused in Italy because high doses cause hallucinations (87). Spontaneous withdrawal symptoms similar to those of opiates have been observed withdrawal symptoms can also be precipitated by naloxone. Zipeprol can be... 

In rare cases, initiation of specific immunotherapy with insect venom leads to recurrent anaphylaxis, even with antihistamine premedication. In those cases, comedication with omalizumab (anti-IgE) has been reported to induce tolerance. In a case of recurrent anaphylaxis to induction of specific immunotherapy, the injection of 300 mg of omalizumab between 4 days and 1 h reportedly led to tolerance [42]. This approach also appears worthy of consideration in patients with both idiopathic recurrent anaphylaxis and mastocytosis who do not respond to standard antimediator therapy, as has been described in 2 atopic patients with ISM [43]. Most patients with mastocytosis and idiopathic anaphylaxis, however, are sufficiently controlled by standard antimediator therapy with antihistamines with or without low-dose corticosteroids. 

Values are the means from six separate experiments. SE was less than 10% of the mean. Dose of test compounds, chlorpheniramine maleate and cetirizine are 10 mg/kg for antihistaminic activity, and 5 mg/kg for sedative-hypnotic activity... 

As sedation is one of the major side effects associated with antihistamines, the test compounds were also evaluated for their sedative potentials. This was determined by measuring the reduction in locomotor activity using an ac-tophotometer [6,7]. The test compounds and the reference standards (chlorpheniramine maleate and cetirizine) were administrated orally at a dose of 5 mg/kg in 1% CMC. 

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. 

Because of their limited effects on allergic symptoms, decongestants often are used in combination with antihistamines.8 Many antihistamines are available in fixed-dose combinations with pseudoephedrine, which enhances the reduction in nasal congestion and allows for the patient convenience of one tablet. Optimally, therapy should be initiated with an antihistamine alone, adding the adrenergic agent only if nasal congestion does not resolve with antihistamine monotherapy. Use of separate antihistamine and pseudoephedrine also permits independent dose titration.4,11,12... 

Intranasal anticholinergic agents (e.g., ipratropium) reduce the severity and duration of rhinorrhea but have no effect on other nasal symptoms.11,12,21 Ipratropium reduces cholinergic hyperreactivity and cholinergically mediated histamine- and antigen-induced secretion. Intranasal ipratropium acts locally, with only minimal systemic absorption. Clinical trials demonstrated that ipratropium bromide 0.3% reduced rhinorrhea in adults and children with PAR.11,12 Intranasal ipratropium is an option for patients in whom rhinorrhea is refractory to topical intranasal corticosteroids and/or antihistamines.8,12 Intranasal ipratropium is available only by prescription, and the dose is two sprays nasally two to three times daily.15 Adverse effects are minimal, but dry nasal membranes have been reported.11,12... 

Clinical trials have indicated that omalizumab, a recombinant humanized monoclonal IgE antibody approved for use in moderate to severe persistent asthma in patients with reactivity to a perennial allergen, is effective in the treatment of SAR.25-27 Omalizumab inhibits the binding of IgE to mast cell and basophil receptors, resulting in a reduction of allergic mediator release.25 Additionally, serum free IgE levels are decreased.2 27 In SAR patients, omalizumab improves quality of life and nasal symptoms and reduces antihistamine needs. The most effective dose in SAR appears to be omalizumab 300 mg administered subcutaneously every 3 to 4 weeks depending on baseline IgE levels.26,27... 

All monoclonal antibodies end in the suffix -mab. The syllable before -mab indicates the source of the monoclonal antibody (see Table 85-4). When administering an antibody for the first time, one should consider the source. The less humanized an antibody, the greater is the chance for the patient to have an allergic-type reaction to the antibody. The more humanized the antibody, the lower is the risk of a reaction. The severity of the reactions may range from fever and chills to life-threatening allergic reactions (which have resulted in death). Premedication with acetaminophen and diphenhydramine is common before the first dose of any antibody. If a severe reaction occurs, the infusion should be stopped and the patient treated with antihistamines, corticosteroids, or other supportive measures. 

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