Type of medicine Antihistamine
Used for Allergies, sickness, vertigo (loss of balance or co-ordination), travel sickness and other problems affecting the ear that affect balance.
Also called Avomine, Phenergan
Available as Tablets, oral syrup and injection

This belongs to the group of medicines known as antihistamines. Phenergan is used to relieve allergies such as skin rashes, itching and symptoms of hayfever.

Phenergan can also be used to treat sickness, vertigo (loss of balance or dizziness), travel sickness and problems affecting the ear. Because Phenergan causes drowsiness, it is also occasionally used to treat insomnia (difficulty sleeping).

Why is this drug prescribed?

Phenergan is derived from a group of drugs called phenothiazines, however, it is also part of the family of sedating antihistamines. Histamine is a chemical in the body that causes the symptoms of an allergic reaction. These can include inflammation of the skin, airways or tissues, rashes, itching of the skin, eyes or nose, nasal congestion and narrowing of the airways. Phenergan blocks the binding of histamine to receptors in many areas of the body and thereby prevents the actions of histamine. This helps prevent and relieve the typical symptoms of an allergic reaction. Histamine may be released from and act in a small area of the body e.g the nose. Alternatively, histamine can result in a serious or complete body reaction e.g. anaphylactic reaction. Phenergan is useful for the prevention or relief of localised or less serious allergies such as hay fever or itchy rash in addition to serious allergic reactions such as anaphylaxis. Phenergan blocks histamine receptors in an area of the brain called the vomiting centre. It also acts to block other receptors in the vomiting centre. Therefore Phenergan prevents the vomiting centre from sending the nerve messages to the stomach that would normally result in vomiting. Phenergan also acts on receptors in the gut to decrease the amount of fluid secreted from the lining of the gut and decrease the actions of the gut muscles. This further aids the treatment or prevention of nausea and vomiting. Phenergan is known as a sedating antihistamine as it enters the brain in significant quantities and causes drowsiness. As a result it is commonly used for the short-term treatment of sleep disturbances and to provide sedation prior to minor procedures or surgery.

Treatments

* Allergic conditions such as hay fever and itchy rash * Difficulty in sleeping * Life threatening allergic reaction * Nausea and vomiting * Sedation prior to surgery

What side effects can this drug cause?

* Headache * Blurred vision * Difficulty in passing urine * Dry mouth * Tiredness * Drowsiness * Confusion * Nightmares * Blood disorders * Restlessness * Abnormal reaction of the skin to light, usually a rash * Dizziness * Abnormal movements of the hands, legs, face, neck and tongue, eg tremor, twitching, rigidity * Unexpected increase in excitability