Promethazine can interact negatively with several medications. Avoid combining it with other central nervous system depressants, such as opioids (codeine, morphine, oxycodone), benzodiazepines (diazepam, alprazolam), or alcohol. This combination significantly increases the risk of respiratory depression, sedation, and even coma. Always inform your doctor or pharmacist about all medications you are taking, including over-the-counter drugs and herbal supplements.
MAO Inhibitors and Promethazine
Combining promethazine with monoamine oxidase inhibitors (MAOIs) can cause a dangerous rise in blood pressure, a condition known as hypertensive crisis. This interaction necessitates a time gap between taking MAOIs and starting promethazine. Consult your physician for the appropriate waiting period before initiating promethazine therapy following MAOI use.
Other Important Interactions
Promethazine may intensify the effects of anticholinergic medications, leading to increased dryness of the mouth, constipation, and blurred vision. It can also interact with certain antidepressants, increasing the risk of serotonin syndrome, a potentially life-threatening condition. Simultaneous use with certain antipsychotics should also be managed carefully under medical supervision, given potential additive sedative effects. Always discuss potential drug interactions with your doctor or pharmacist before starting any new medication while taking promethazine.