Promethazine hydrochloride is an antihistamine, anti-emetic, and sedative. It is available as a tablet, syrup, injection, or as a suppository. There are a number of side effects and drug interactions that may occur while taking promethazine hydrochloride, including some rare but serious ones, and there are precautions that need to considered before taking it.
This drug is commonly used as an antihistamine, meaning that it relieves the symptoms of allergies, such as stuffy or runny nose, red and watering eyes, hives, and itching skin. It also relieves those same symptoms if they are caused by the common cold. Promethazine can be used to lightly sedate patients before surgery or labor as well as to control the nausea and vomiting that may occur after surgery. Nausea caused by motion or seasickness can also be treated using this medication.
A variety of side effects may occur while taking promethazine hydrochloride, including dizziness, drowsiness, dry mouth, nausea, restlessness or agitation, and problems sleeping. Uncontrollable movement or twitching of facial features or limbs is a sign of a serious reaction, and medical attention should be sought immediately. Itching, hives, swelling, and difficulty breathing indicates an allergic reaction that can progress quickly into an emergency situation. Any unexplained problems with pain, consciousness, breathing, vision, urination, mood, or movement may also indicate an adverse reaction, and patients should contact the prescribing doctor for any concerning, acute, or persistent side effects.
Children over the age of 2 should not be given promethazine hydrochloride without the supervision of a doctor, and it should never be given to children and infants under the age of 2. This medication can be very dangerous or fatal to children, causing breathing problems or cessation of breathing. Children who have been given promethazine need to be carefully observed, and medical attention should be sought for any breathing problems. It is not known if this medication could harm an unborn or nursing baby, so a woman's doctor needs to know if she is pregnant or nursing before promethazine is prescribed.
Many medications may interact with promethazine hydrochloride, including antidepressants, anti-anxiety medications, antihistamines, sleeping pills, and sedatives. Any medical professional treating a patient taking promethazine hydrochloride or prescribing it needs to know about all medications taken, including vitamins and herbal supplements. A history of breathing problems or seizures may affect a patient's suitability or dosage requirements, and so the prescribing doctor also needs to know the patient's full medical history.