Antihistamine contraindications

Why are antihistamines contraindicated in a patient taking a monoamine oxidase (MAO) inhibitor ... 

Carbocisteine is a mucolytic agent that may be used in chesty cough. Antihistamines tend to have antimuscarinic properties, resulting in urinary retention and are therefore contraindicated in prostatic hypertrophy. 

Second-generation antihistamines Flypersensitivity to specific or structurally related antihistamines. Desloratadine is contraindicated in those who are hypersensitive to loratadine. Cetirizine is contraindicated in those who are hypersensitive to hydroxyzine. 

Lactation Antihistamine therapy is contraindicated in nursing mothers. 

Coadministration of ritonavir with certain nonsedating antihistamines, sedative hypnotics, antiarrhythmics, or ergot alkaloid preparations may result in potentially serious and/or life-threatening adverse reactions due to possible effects of ritonavir on the hepatic metabolism of certain drugs (see Contraindications). 

Contraindications Acute asthmatic attack, patients receiving MAO inhibitors, history of hypersensitivity to antihistamines... 

Moderate-severe persistent intranasal corticosteroids are the drug of choice. Antihistamines, intranasal decongestants, and sodium cromoglicate are alternatives if steroids are contraindicated, or can be used as add-on drugs. Ipratropium bromide is useful for people with persistent watery effusion. 

Both Vicks Sinex, which contains oxymetazoline, and Sudafed, which contains pseudoephedrine, should be stopped because these are contributing to some of his symptoms, (rebound effect). Recommend a once-a-day non-sedating antihistamine. However, only cetirizine is safe - the other antihistamines are contraindicated because of his history of porphyria. 

Antihistaminics are popular as nonprescription (over-the-counter) sleep remedies (e.g., diphenhydramine, doxylamine, p. 118), in which case their sedative side effect is used as the principal effect. The hypnotic effect is weak adverse effects (e.g., atropine-like) and corresponding contraindications need to be taken into account. 

Macrolide antibiotics are contraindicated in patients with known hypersensitivity or intolerance to any macrolide. Because clarithromycin can have adverse effects on embryo-fetal development in animals, this drug should be avoided in pregnant women unless no other therapy is appropriate. Concurrent administration of the macrolides and astemizole or terfenadine can cause elected antihistamine levels, resulting in life-threatening cardiac arrhythmias, and should be avoided. 

Hi antihistamines are contraindicated in cases of known hypersensitivity reactions to individual agents. Oral preparations are also contraindicated in nursing mothers and in the third trimester of pregnancy.The Hi... 

Answer D. Sucralfate polymerizes in the GI tract, forming a protective gel-like coating of ulcer beds —healing and 4- ulcer recurrence. Overall, proton pump inhibitors such as omeprazole provide more rapid pain relief and faster healing than antihistamines in ulcers caused by acid secretion. Misoprostol activates PGEj receptors, not omeprazole. Not all GI ulcers are associated with Helicobacter pylori, so a cure rate of 98% is not feasible in principle and (at best) is only in the 95% range in treatment of ulcers established to be associated with the bacterium. Anti-inflammatory steroids cause GI ulcers and would be contraindicated. 

Tripelennamine is contraindicated in patients with known hypersensitivity to similar chemical structures, such as pyrilamine in neonates, other infants, and breastfeeding women because young children may be more susceptible to the toxic effects of antihistamines during asthma attacks because it thickens bronchial secretions and in patients who have taken MAO inhibitors within the preceding two weeks. 

PRECAUTIONS AND CONTRAINDICATIONS Population-based therapy with diethyl-catbamazine should be avoided in areas where onchocerciasis or loiasis is endemic, although the drug can be used to protect foreign travelers from these infections. Pretreatment with glucocorticoids and antihistamines often is given to minimize indirect reactions to diethylcarbamazine that result from dying microfilariae. 

Describe the uses, general drug adion, general adverse readions, contraindications, precautions, and interactions of the antihistamines and decongestants. 

See antihistamines in the Appendix. Detailed tables show doses, recommendations, expectations, side effects, contraindications, and more available on the book s Web site (see URL in Appendix). 

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. 

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