How Long To Wait After Taking Klonopin To Take Oxycodone

In our latest question and answer, the pharmacist discusses how long to wait after taking Klonopin to safely take Oxycodone.


I am currently taking 3mg of Klonopin at night. I just had surgery and was prescribed Percocet 5/325. How many hours should I wait after taking Klonopin to take Percocet?

Asked by Chris On Jun 19, 2018

Answered by
Medical Content Reviewed By PharmacistAnswers Staff

On Jun 19, 2018

Percocet PillsPercocet and Klonopin (clonazepam) do interact and can lead to a greater risk for adverse events that include sedation and respiratory depression. In fact, the seriousness of the interaction led the FDA to release a strong warning regarding the combination of benzodiazepines, like Klonopin, and opioid medications, such as Percocet (oxycodone/acetaminophen).

If you need to initiate treatment of Percocet while taking Klonopin, you should start at the lowest possible dose to achieve pain relief while watching for signs of excessive sedation and respiratory depression. You should only take these medications together under the supervision of a healthcare professional and if other pain treatment options are deemed inappropriate.

How Long Does Klonopin Last In The Body?

In reference to your specific question as to when it would be safe to take Percocet after Klonopin, the answer varies by individual, and by situation. If you want to completely avoid having Klonopin in your system by the time you take Percocet, you'll be waiting a long time.

Klonopin has a long half-life (time it takes for 50% of a drug to be metabolized in the body). The reported half-life is 22 to 33 hours in children and 19 to 50 hours in adults. For adults, this means that it can sometimes take 5 to 10 days before it is completely cleared from the body! So, if you are looking to completely avoid having Klonopin present in your system, you need to wait at least 5 to 10 days.

The medicinal effects of Klonopin however, last for shorter periods of time. The duration of action of Klonopin is between 6 to 12 hours. Therefore, if you wish to avoid additive sedation, you should wait at least that long before taking Percocet. The risk of respiratory depression also decreases, but is not completely eliminated, after 6 to 12 hours.

If your doctor has prescribed both Klonopin and Percocet to you, be sure to discuss a proper dosing schedule with them.

About the Pharmacist

Dr. Adam DeRue Pharm.D

Dr. Adam DeRue is a Doctor Of Pharmacy and registered pharmacist. He graduated from the Albany College of Pharmacy in 2008.

About Klonopin (Clonazepam)

Klonnopin (clonazepam) is an oral benzodiazepine used primarily in the management of seizures but is also used for the treatment of anxiety and short-term insomnia. Klonopin is considered a rapid acting benzodiazepine with an intermediate duration of action. After taking by mouth, the onset of effect is generally 15-30 minutes, with the duration of action being between 6 and 12 hours. Clonazepam metabolism does not create active metabolites and it is not thought to accumulate in the body. Klonopin may be taken without regard to food but should be taken with a full glass of water.

About Percocet (Oxycodone/Acetaminophen)

Percocet is a combination of oxycodone and acetaminophen. Oxycodone and acetaminophen are used together to treat moderate to severe pain. Acetaminophen is a non-salicylate analgesic and is used to potentiate the analgesic effects of oxycodone. Oxycodone is an oral opiate agonist.

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