Codeine works in a similar manner as heroin, targeting the opiate receptors in your brain to alleviate pain. It is typically prescribed orally, but it can also be taken through an IV. It can be combined with acetaminophen (Tylenol) or ibuprofen to treat certain types of pain. Codeine can also be misused in an effort to experience feelings of pleasure or euphoria. It is important to speak with your doctor if you are taking other medications or supplements, especially antifungal medicines; antibiotics such as erythromycin (Erytab, Erythrocin); anticholinergic drugs such as atropine and benztropine; sedatives such as diphenhydramine (Benadryl); heart or blood pressure medications; muscle relaxants; or HIV medications including indinavir (Crixivan), nelfinavir (Viracept) and ritonavir (Norvir, in Kaletra).
How long does codeine stay in your system depends on several factors, most importantly how much you take and in what dosage. Individuals with healthier organs process drugs more quickly, while those who have a poor diet or are older will find that it takes longer for the body to break down and eliminate drug metabolites.
It also depends on the type of test used to detect codeine. Urine tests are most common, but blood and hair follicle testing can be utilized if urine samples are unavailable. Blood tests can detect codeine in the body for about 24 hours, while saliva and hair follicle tests can identify it for up to a week.
Long-term use of codeine can lead to serious and even life-threatening side effects, including breathing problems, slowed heart rate, mental confusion, stomach upset, vomiting, seizures and liver or kidney failure. People with underlying health conditions like slowed breathing or a history of substance use disorder are at a greater risk of experiencing these adverse reactions to the medication.