Is There A Difference Between Delayed-Release And Extended-Release Medications?

Scanning through various options of over-the-counter medications can sometimes be overwhelming. Allergy medications have 12-hour and 24-hour formulas, and some pain relievers work for a few hours – or for 12 hours. Most medications are immediate release, which means that the drug works as soon as your body absorbs it, according to GoodRx. Once these medications leave your body, you'll need to take them again to continue the medicine's effect.

So you don't have to be popping medications several times a day, drug manufacturers have created modified-release versions of medications. There are subtle differences among these forms of medication that depend on a medication's possible side effects, how long the drug works in the body, or what part of the body the drug is targeting. Extended-release medications are designed to last longer than immediate-release medications so that you don't have to take as many doses. Delayed-release medications often have an enteric coating that prevents them from being immediately absorbed by the stomach. That way, the drug can be absorbed in a certain part of the body to target that area — such as drugs that treat ulcerative colitis in the large intestine.

According to a 2015 article in the Journal of Clinical Psychiatry, delayed-release medications can reduce side effects such as nausea because the drug stays intact until it reaches the small or large intestine (rather than the stomach). Delayed-release drugs can also minimize GI distress because they are released along the gastrointestinal tract — rather than at one specific place in the gut. It should be noted that delayed-release and extended-release aren't the same. Delayed-release drugs usually release the entire dose, whereas extended-release medications allow the medication to take effect in small doses over time. A delayed-release drug may still have to be taken more than once a day.

Side effects of medications can be reduced with extended-release forms of the drugs because they avoid having a strong concentration of the drug in the blood all at once. For example, an extended-release form of bupropion reduces the risk of seizures (when compared to the immediate-release form). Extended-release drugs include both controlled-release and sustained-release drugs. In particular, controlled-release medications can help keep the level of a drug consistent in the blood. This can be beneficial with sleep medications such as zolpidem (Ambien), which wears off after two to three hours in its immediate-release form.

Although modified-release medications can limit side effects and keep levels of a drug relatively consistent in your body, these forms of medication have some disadvantages to consider, according to a 2013 article in the Journal of Chemical and Pharmaceutical Sciences. If the dose of your modified-release medication is toxic to your system, it will continue to be toxic for much longer than immediate-release medications. Modified-release medications are also difficult for doctors to establish the correct dose for you.

These forms of medication also require less wiggle room in taking your medication. In other words, if you skip a dose in the morning, you might not be able to take it at lunchtime. Delayed-release and extended-release forms of medication also can't be split or crushed to make it easier to swallow. Breaking or chewing these medications will release the medicine too quickly in your system — or cause it to be released in the wrong place.