What Are the Different Promethazine Interactions?

Promethazine is a medication that is often prescribed to treat symptoms of allergic reactions, as well as to control nausea following a surgery. There are many potential promethazine interactions that can produce side effects. The drug may interact with other medications, and it may also react adversely with certain medical conditions that the patient may have. In addition, patients must be careful to use the drug correctly, or they run the risk of an overdose and other complications.

A wide range of other medications may cause promethazine interactions. Patients must disclose all other drugs and supplements they take, such as tranquilizers, sleeping pills, and sedatives, as well as pain medicines like narcotics. Promethazine interactions may also occur with chemotherapy drugs, antihistamines, and barbiturates. Antidepressants, monoamine oxidase (MAO) inhibitors, and motion sickness drugs may also cause an interaction.

Patients should also disclose any medicines that they take to treat Parkinson's disease, irritable bowel syndrome, and mental illnesses, as well as urinary problems, seizures, and ulcers. Other medications that can interact with promethazine can include lithium, bronchodilators, and blood thinners like warfarin. Belladonna, blood pressure medications, and drugs that treat pituitary gland tumors should not be combined with promethazine.

Any other medical conditions that the patient have should also be disclosed to avoid additional promethazine interactions. Promethazine may be contraindicated for use by those with ulcers, seizures, or a medical condition that might interfere with the production of blood cells. Glaucoma, an enlarged prostate, and blockages in the bladder, stomach, or intestines may also preclude a person from using this drug. A child may be unable to use promethazine if he exhibits excessive vomiting or diarrhea, flu-like symptoms, or aggression, as well as listlessness and confusion.

Certain other conditions and lifestyle choices may result in promethazine interactions. Patients should avoid consuming alcohol, because this can worsen the potential side effects. Since the drug can make a person's skin more sensitive to sunlight, patients should avoid prolonged exposure to sunlight. Women who are pregnant or breastfeeding should discuss the risks with their doctors. Elderly adults may be at a higher risk of developing side effects, and children younger than two years old should never use this drug.

In addition, an overdose may occur if the patient exceeds his prescribed dosage. This requires emergency medical care, and may be indicated by slowed or stopped breathing, labored breathing, and loss of consciousness. Patients may exhibit abnormal excitement, continuous movements of the hands and feet, or they may have very tight muscles that they cannot move freely. They may also have wide pupils, a dry mouth, and a fast heartbeat. An overdose of promethazine can also cause nausea, constipation, and dizziness.