Some products that may interact with this drug include: antihistamines applied to the skin (such as diphenhydramine cream, ointment, spray), cimetidine, metoclopramide, naltrexone, samidorphan. buy promethazine with codeine syrup  

The risk of serious side effects (such as slow/shallow breathing, severe drowsiness/dizziness) may be increased if this medication is taken with other products that may also cause drowsiness or breathing problems. Tell your doctor or pharmacist if you are taking other products such as other opioid pain or cough relievers (such as morphine, hydrocodone), alcohol, marijuana (cannabis), drugs for sleep or anxiety (such as alprazolam, lorazepam, zolpidem), muscle relaxants (such as carisoprodol, cyclobenzaprine), or other antihistamines (such as cetirizine, diphenhydramine).

Check the labels on all your medicines (such as allergy or cough-and-cold products) because they may contain ingredients that cause drowsiness. Ask your pharmacist about using those products safely.

Other medications can affect the removal of codeine/promethazine from your body, which may affect how codeine/promethazine works. Examples include azole antifungals (such as ketoconazole), bupropion, fluoxetine, macrolide antibiotics (such as erythromycin), paroxetine, quinidine, rifamycins (such as rifabutin, rifampin), ritonavir, certain drugs used to treat seizures (such as carbamazepine, phenytoin), among others. 

This medication may interfere with certain lab tests (such as some pregnancy tests, blood sugar tests, amylase/lipase levels), possibly causing false test results. Make sure lab personnel and all your doctors know you use this drug. order promethazine