Codeine appears in dozens of prescription medications, most of them combination products that pair codeine with a pain reliever, antihistamine, or decongestant. You’ll find it in pain tablets, cough syrups, headache capsules, and in some countries, certain over-the-counter preparations. Here’s a breakdown of the most common ones and what’s actually in them.
Pain Relievers With Codeine
The most widely recognized codeine product is Tylenol with Codeine, which combines acetaminophen (325 mg) with varying amounts of codeine. The numbered versions correspond to the codeine strength: No. 1 has 7.5 mg, No. 2 has 15 mg, No. 3 has 30 mg, and No. 4 has 60 mg. Generic versions of acetaminophen with codeine are still commonly prescribed for mild to moderate pain, particularly after dental procedures or minor surgeries.
Codeine is also combined with aspirin in some formulations, though these are less common today than the acetaminophen versions.
Cough and Cold Medications
Codeine suppresses the cough reflex, which is why it shows up in a number of prescription cough syrups. The most common pairing is promethazine with codeine, where promethazine acts as an antihistamine and anti-nausea agent. Several brand names carry this combination:
- Phenergan with Codeine (promethazine and codeine)
- Prometh VC with Codeine (promethazine, a nasal decongestant, and codeine)
- Tuzistra XR (chlorpheniramine and codeine)
- Tuxarin ER (chlorpheniramine and codeine)
- Triacin-C (codeine-based cough formula)
Some older cough products combined codeine with bromodiphenhydramine, an antihistamine, under names like Ambenyl and Bromotuss with Codeine. Many of these branded products are no longer on the market, though generic equivalents may still be available.
Robitussin AC is a well-known cough preparation containing a small amount of codeine per dose. Because of the low concentration, products like this fall under a less restrictive drug schedule than pain tablets.
Headache and Migraine Capsules
Fiorinal with Codeine is a four-ingredient capsule designed for tension headaches. Each capsule contains 50 mg of butalbital (a mild sedative), 325 mg of aspirin, 40 mg of caffeine, and 30 mg of codeine. It’s also sold under the brand name Ascomp with Codeine. In Canada, similar formulations are marketed under names like Fiorinal-C and Trianal C in half- and quarter-strength versions.
A related product, Fioricet with Codeine, swaps the aspirin for acetaminophen while keeping the same butalbital, caffeine, and codeine combination.
How Codeine Works in the Body
Codeine is technically a “prodrug,” meaning it doesn’t do much on its own. Your liver converts it into morphine using an enzyme called CYP2D6, and it’s that morphine that actually relieves pain and suppresses coughing. Only about 5 to 10 percent of the codeine you take gets converted this way. The other 80 percent or so turns into inactive byproducts your body simply eliminates.
This conversion rate varies dramatically from person to person based on genetics. Some people are “ultra-rapid metabolizers” who convert far more codeine into morphine than average, raising the risk of side effects. Others are “poor metabolizers” who barely convert any, which means codeine gives them almost no pain relief at all. This genetic variability is one reason codeine has fallen out of favor compared to other pain medications.
How Codeine Products Are Scheduled
Not all codeine products carry the same legal classification. Pure codeine is a Schedule II controlled substance, the same category as oxycodone and fentanyl. But when codeine is mixed into combination products, the scheduling drops based on the amount per dose.
Combination tablets with less than 90 mg of codeine per dose, like Tylenol with Codeine, are classified as Schedule III. Cough preparations with less than 200 mg of codeine per 100 milliliters of liquid, like Robitussin AC, fall under Schedule V, the least restrictive category for controlled substances. All of these still require a prescription in the United States.
Over-the-Counter Codeine Outside the U.S.
In some countries, low-dose codeine products are available without a prescription. In parts of Canada, products containing no more than 8 mg of codeine per tablet (or 20 mg per 30 mL of liquid) can be sold over the counter, as long as the codeine is combined with other non-narcotic ingredients like acetaminophen or aspirin. These are sometimes called “exempted codeine products.”
This is changing, though. Several Canadian provinces, along with Australia, New Zealand, and other countries, have reclassified all codeine-containing products as prescription-only due to safety concerns and their role in opioid misuse. The U.S. has required a prescription for codeine products for years.
Common Side Effects
Because codeine converts to morphine, it shares many of the same side effects as other opioids: drowsiness, constipation, nausea, and lightheadedness. These tend to be milder than with stronger opioids but are still noticeable, especially at higher doses. Codeine also carries a real risk of dependence with regular use, which is why it’s reserved for short-term treatment in most cases.
The combination ingredients in these products add their own risks. Acetaminophen can cause liver damage if you exceed the daily limit, so taking extra Tylenol alongside Tylenol with Codeine is a common and dangerous mistake. Aspirin-containing formulations like Fiorinal with Codeine carry bleeding risks. Promethazine-codeine cough syrups cause significant sedation, which intensifies if combined with alcohol or other depressants.
Codeine is not recommended for children following tonsil or adenoid surgery, and the FDA has restricted its use in children broadly due to the unpredictable way young patients metabolize the drug.