Histamine is a chemical that is released by the body as a reaction to an allergic substance. Antihistamines block the effects of this chemical on the respiratory system, helping to prevent or relieve the symptoms of allergies. Although quite effective, there are certain dangers involved in the use of antihistamines.
Sleepiness
According to the American Academy of Family Physicians, antihistamines tend to make an individual drowsy and sleepy. This makes it dangerous for a person to operate any heavy machinery or drive while taking these drugs. Dizziness is another side effect of these drugs. The person may also find it hard to think clearly and decision-making may be affected.
Abdominal Discomfort
Some of these antihistamines can make an individual experience pain in the abdomen, as reported by MayoClinic.com. Nausea and gastrointestinal upset may also be experienced by the person taking these drugs. Belching, diarrhea and constipation are some of the other gastrointestinal dangers involved with taking these drugs.
Clumsiness and Convulsions
MayoClinic.com reports that an overdose of antihistamines could be dangerous for the individual. The person in this case may become clumsy with an unsteady gait. Convulsions or seizures may also occur. The drowsiness that is common with these medications may be severe in case of an overdose. Hallucinations, characterized by seeing, hearing or feeling things that are not present, may be felt. Flushing or redness of the face and shortness of breath are other signs of an overdose of antihistamines. There may also be difficulties in sleeping and feeling of faintness.
Other Dangers
There are certain other dangers and side-effects of antihistamines. MayoClinic.com reports that increased appetite and weight gain may occur. The mucus may become thick and the person may experience congestion. Headaches are another side-effect of these medications. There may be changes in vision. Painful urination and pain during menstruation may be experienced. American Academy of Family Physicians reports that dryness in the mouth, nose or throat is another side effect of these drugs. Fever, increased sensitivity of the skin to the sun, fast heartbeat and hoarseness are also side-effects that an individual may experience.
