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Drugs, response antihistaminics

There is an increased risk for bone marrow suppression when levamisole or hydroxyurea are administered witii other antineoplastic dni. Use of levamisole witii phenytoin increases die risk of phenytoin toxicity. Pegaspargase may alter drug response of the anticoagulants. When procarbazine is administered with other central nervous system (CNS) depressants, such as alcohol, antidepressants, antihistamines, opiates, or the sedatives, an additive CNS effect may be seen. Procarbazine may potentiate hypoglycemia when administered witii insulin or oral antidiabetic dru . ... [Pg.594]

Differences in receptor sensitivity have been offered to explain the spectrum of unexpected drug responses observed in children. Neonates and young children are at increased risk to experience paradoxical CNS stimulation following antihistamine administration. Symptoms observed in pediatric cases of acute overdose include hallucinations, excitation, and seizures. A physiological explanation for this reaction has not been identified. Antihistamines should not be included in over-the-counter (OTC) cough and cold products recommended for infants and young children. [Pg.669]

Antihistamines are prescribed to help the itching (pruritus) but should be used as directed because decreased liver function increases the risk for altered drug responses. [Pg.123]

Patients with chronic idiopathic urticaria, who develop cutaneous reactions in response to aspirin, display certain similarities in eicosanoid profile with AIA. The mechanism of the reactions is often related to COX-1 inhibition [18]. Therefore, aspirin and all drugs that inhibit COX-1 should be avoided in patients who already have had cutaneous reactions to NSAID. Coxibs are usually well tolerated, although occasional adverse reactions have been reported [19, 20]. For treatment of the reactions, antihistamines are usually sufficient, but in more severe cases adrenaline and corticosteroids may be warranted. [Pg.176]

In AIT, patient selection is critical. The allergic cause of AR should be verified by history and skin or blood tests. Additionally, the responsible antigen(s) must be identified. Patients who may benefit from AIT include those who do not tolerate traditional drug therapy (e.g., nosebleeds with intranasal steroids and sedation with antihistamines), suffer from severe symptoms, have comorbid conditions (e.g., asthma and sinusitis), fail drug therapy, or prefer not to take long-term medication.11 22"24... [Pg.932]

It was noted, however, that a subset of responses known to be triggered by histamine failed to be blocked by the classical antihistaminic drugs. This, as well as further sophisticated pharmacological work, led to the classification of histamine receptors as and Hg. To simplify grossly, the receptor controls the responses familiar to every hayfever sufferer these effects can be alleviated readily by classicial antihistamines. The latter interestingly bear little or no structural similarity to histamine... [Pg.250]

At therapeutic doses, the first- and second-generation antihistamines are equilibrium-competitive inhibitors of Hi-receptor-mediated responses. Certain second-generation drugs are noncompetitive inhibitors at high concentrations. Both first- and second-generation compounds have negligible abilities to block the H2-, H3-, or H4-receptors. The therapeutic effectiveness of these... [Pg.453]

The foregoing bases are usually employed as their salts with maleic, tartaric or hydrochloric acid. They usually depress the CNS, producing drowsiness and other side-effects that may preclude the use of a particular drug, but responses of different patients vary. Since antihistamine activity is shown by many compounds of varied structure it is suggested that they do not fit the histamine receptor completely as histamine does, but merely cover the anionic site, with their aryl residues adsorbed on some adjacent area. These compounds do not influence histamine-induced gastric secretion, and it was concluded that the latter effect is produced by a different type of histamine receptor, termed the H2 receptor. Most other effects of histamine are attributed to the Hi receptor. [Pg.178]

Other products from histidine include the hormonal substance histamine formed by decarboxylation, the oxidation product, imidazole acetic acid, and N5- and A/c-methylhistidines. Histamine plays a role in release of gastric secretions and allergic responses (Chapter 5). Drugs (antihistamines) that inhibit its release are in widespread use. The unusual amino acid diphthamide has an unknown function in pro-... [Pg.1450]


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See also in sourсe #XX -- [ Pg.129 ]




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