Chlorpheniramine is a member of a class of drugs known as antihistamines, which are often used to treat allergy symptoms. This medication is available in various forms, with the polistirex form being used to provide extended relief from symptoms. Polistirex is a digestible plastic, safe for human consumption, that takes some time to be broken down in the body. By attaching this antihistamine to the plastic, chlorpheniramine polistirex is formed, and remains effective in most people for 10 to 12 hours. Often, this medication is administered in tablet or liquid form.
One of the main ways that allergy symptoms are caused is through immune cells that release a compound called histamine. Histamine can have many effects on the body, including runny nose, red eyes, and itchiness. Chlorpheniramine polistirex binds to the same sites on receptor cells that histamine normally would, and thereby prevents histamine molecules from evoking a response. This relief lasts as long as the drug remains in the bloodstream. The extended release nature of this medication allows it to stay in the body longer, eliminating the need for frequent re-dosing in order to obtain a consistent level of symptom reduction.
Some preparations of chlorpheniramine polistirex combine it with other medications in order to better treat multiple symptoms. One of the more common combinations is a mixture of this form of chlorpheniramine with hydrocodone polistirex. Hydrocodone acts as a cough suppressant, so this medication is used as a therapy for allergies that include severe coughing. Other medications may feature a mixture of chlorpheniramine and a decongestant.
Like any drug, chlorpheniramine polistirex can sometimes cause side effects in some people. Some of these effects that occur more frequently include a dry mouth, constipation, problems swallowing, and sleepiness. In large doses, disorientation, confusion, and hallucinations can occur, which is why many products containing this drug discourage exceeding the recommended dosage.
Other drugs may occasionally interact with chlorpheniramine polistirex, leading to intensified effects or additional side effects. For this reason, caution should be used when taking this drug at the same time as other substances, especially those that cause drowsiness. Some of the more common substances that can potentially cause interactions include alcohol, other allergy medications, narcotic pain relievers, sleeping pills, and anti-anxiety drugs, such as diazepam. Chlorpheniramine shows some signs of having effects that are similar to some types of antidepressants, such as fluoxetine, as well, so care should be taken with combining these types of medications.