Antihistamines: allergies treated with

Although these drug s are sometimes used to treat allergies, a drug allergy can occur with the use of an antihistamine Symptoms that may indicate an allergy to these drugs include skin rash, urticaria, and anaphylactic shock. 

The same molecules used to treat allergies and cold symptoms have many other uses. Antihistamines are particularly effective as antiemetics in suppressing nausea associated with gastrointestinal illnesses. They can also be used to treat the symptoms of motion sickness or even vestibular disturbances (vertigo). Because of their ability to induce sedation, antihistamines are widely used in over-the-counter sleep aids. 

Antihistamines bind to the same active site of the enzyme that binds histamine in the cell, but they evoke a different response. An antihistamine like bFompheniramine, for example, inhibits vasodilation, so it is used to treat the symptoms of the common cold and allergies. Cimetidine (trade name Tagamet) is a histamine mimic that blocks the secretion of hydrochloric acid in the stomach, so it is used to treat individutils with ulcers. 

Antihistamines, used to treat allergies, can cause some side effects, like drowsiness, dizziness, nervousness, mild euphoria, and tremors, even when used medicinally at suggested doses. Abusers who take many times the recommended amount experience more intense side effects. Along with the enhanced euphoria they are looking for, the other side effects are also increased. Additionally, muscle spasms, irregular heartbeat, faintness, and convulsions can also occur with extremely high levels of antihistamines. 

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