Promethazine is a versatile medication used for various purposes. Overall, promethazine is a versatile medication with multiple uses as an antihistamine, antiemetic, and sedative. It is effective for treating allergies, nausea and vomiting, and insomnia, but it should be used with caution and under the guidance of a healthcare professional due to the risk of side effects and drug interactions.
Key points:
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Antihistamine: Promethazine is primarily known as a first-generation antihistamine. It works by blocking the effects of histamine, thereby relieving symptoms of allergies such as itching, sneezing, runny nose, and watery eyes.
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Antiemetic: Promethazine also has antiemetic properties, meaning it helps to alleviate nausea and vomiting. It is often used to prevent and treat motion sickness, nausea and vomiting associated with surgery or anesthesia, and chemotherapy-induced nausea and vomiting.
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Sedative: Promethazine has sedative effects and is sometimes used for its calming and sleep-inducing properties. It is sometimes prescribed to help with insomnia or to induce sleep before surgery.
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Dosage Forms: Promethazine is available in various forms, including oral tablets, oral syrup, rectal suppositories, and injectable formulations. The dosage and administration route depend on the condition being treated and the patient's age and weight.
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Side Effects: Common side effects of promethazine may include drowsiness, dizziness, dry mouth, blurred vision, constipation, and urinary retention. It can also cause more serious side effects such as respiratory depression, especially when used in higher doses or in combination with other medications that depress the central nervous system.
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Contraindications: Promethazine is contraindicated in certain populations, including individuals with a history of hypersensitivity to promethazine or other phenothiazines, patients with severe central nervous system depression, and children under two years old due to the risk of respiratory depression.
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Drug Interactions: Promethazine may interact with other medications, including opioids, benzodiazepines, and other medications that depress the central nervous system. It may also enhance the effects of certain medications used to treat Parkinson's disease.
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Black Box Warning: Promethazine carries a black box warning regarding the risk of respiratory depression and death in pediatric patients less than two years old who are given promethazine. This warning emphasizes the importance of using caution and appropriate dosing when prescribing promethazine to children.