Last updated : July 14, 2025
Codeine is a prescription medication used to relieve mild or moderate pain. It’s also used as a prescription-strength cough suppressant. If an employee is using a medication that contains codeine, it will show up on a drug test. The amount of time that it remains in the system varies depending on the testing method.
Opiates are regulated by the Controlled Substances Act and because codeine is formulated in a variety of ways, it’s classed at either a Schedule 2, 3, 4, or 5. Moreover, as with other drugs in the opiate category, it carries a high potential for misuse and can cause physical dependence.
Steady use of the drug causes the body to develop a tolerance. That means that users have to increase the dosage to reach the desired effect. That’s a dangerous scenario for abusers because it puts them at a higher risk of overdosing on the drug.
It appears that young people are much more likely to abuse codeine medications because they consider it a “low risk” drug. That’s because even though codeine is converted to morphine within the body, it’s only 8 to 12% as powerful. Sadly, though, increasing the dosage can be dangerous.
Increasing the dosage not only puts the user at risk of addiction but for many, it’s truly a gateway drug. They eventually move on to stronger opioids such as Vicodin or heroin.
Signs and side effects
It’s important to recognize the signs of codeine use in the workplace.
Signs of use include:
- Confusion
- Lethargy and fatigue
- Labored breathing
- Mood changes
- Chronic itching
- Weight loss
- Clammy hands or feet
- Stomach pain
- Withdrawing from family and friends
The relaxed, euphoric state of mind that codeine produces is what the abuser is after, but there are other side effects that can be dangerous—especially after long-term use.
- Increased risk of lung infections
- Bowel damage
- Sleep disorders
- Irregular heartbeat
- Brain damage
For some people, withdrawal symptoms may seem like a bad case of the flu. Withdrawal from codeine may not be life-threatening but it’s definitely uncomfortable. It’s best if long-term users consult a doctor for help beating their addiction. Withdrawal is more intense and they may revert to using again to relieve the symptoms.
Withdrawal symptoms include:
- Runny nose
- Watery eyes
- Nausea
- Vomiting
- Stomach cramps
- Diarrhea
- Loss of appetite
- Weight loss
- Muscle pain
Because there is a risk of overdose, it’s important to recognize the signs.
They are:
- Slow, labored breathing
- Cold, clammy skin
- Extreme drowsiness or fatigue
- Dizziness
- Weakness
- Lightheadedness
- Loss of consciousness
- Low blood pressure
- Muscle twitches
- Weak pulse
- Bluish lips or fingernails
Physicians can treat an overdose using medications that block the receptors in the pleasure center of the brain. However, the intervention must be quick enough to prevent brain damage due to oxygen deprivation.
It’s also important to note that relapse can be extremely dangerous because most people are unaware that even a short break can result in a reduction of tolerance. Many begin using the same amount of the drug that they were using when they stopped. It can result in a dangerous overdose.
Testing methods
The amount of time that any drug is identifiable in the system depends on the type of drug test that is used.
Blood test
Blood tests detect current impairment because they identify the parent drug rather than drug metabolites. Employers rarely use them for employee drug testing though because they’re very expensive. They are the most invasive drug test and must be performed in a medical setting by qualified personnel.
Codeine is only detected in a blood test up to 24 hours after ingesting the drug.
Urine test
Urine tests are the most cost-effective choice for employers. They’re so commonly used that when someone is told they’ll be taking a drug test, they expect it to be the urine test.
Urine tests don’t identify current impairment because instead of the parent drug, the test identifies drug metabolites that remain in the system. Depending on the frequency of use, urine tests detect codeine between one and three days.
Hair follicle test
The least invasive drug test is the hair follicle test. A quick snip with the scissors and the technician has a sample for testing. If someone has thin hair and there’s a risk of leaving a noticeable “bald” spot, technicians collect the hair from several areas of the head.
Hair tests identify any and all drug use for a ninety-day period. So, even though they are more expensive, many employers overlook the added expense to take advantage of the lengthy detection period.
In fact, the DOT (Department of Transportation) has requested that the testing method be changed from the urine test to the hair follicle test. The request isn’t expected to meet with any resistance so it appears that it’s just a matter of time before the change is made.
Hair follicle tests don’t detect current impairment because it takes several days for the metabolites to begin growing out into the hair shaft.
Mouth swab test
This test is gaining popularity due to the advancements made in drug testing technology. Employers who want to determine recent drug use choose the oral fluid test. In fact, the test detects many drugs almost immediately, but they are unable to detect current impairment because there’s no way to determine whether the test has identified the parent drug or the drug’s metabolites—yet.
A mouth swab test identifies codeine for up to 72 hours. It’s important to note though that research has determined that chewing gum or eating candy that contains citric acid can lower the levels of codeine found in saliva, but it doesn’t eliminate them entirely.
Varied detection periods
In addition to the type of drug test used, other contributing factors are:
- Frequency of use
- Dosage
- Weight
- Age
- Metabolism
- Hydration level
- Level of activity
- Other health conditions
The reason we drug test
The number one reason that employers drug test is to provide the safest work environment possible for everyone.
Drugs in the workplace increase the risk of accidents and lower productivity.
Furthermore, if an employee tests positive for codeine or any drug, it’s an opportunity to urge them to seek help.
