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K 18 Pill: What Kind of Pill Is This?

Key Points

  • K18 is an oxycodone pill.
  • Oxycodone is a powerful opioid.
  • Oxycodone works by releasing endorphins like dopamine.
  • There are many side effects.
  • Do not abuse this pill under any circumstances.

If you see a pill with “K18” on it, that’s a 5mg tablet with the active ingredient Oxycodone Hydrochloride manufactured by KVK Tech in Newtown, Pennsylvania, USA. Because It is prescribed for pain management and has a high potential for opioid addiction, it is a Schedule II controlled substance.[1] That means it is illegal to have without a doctor’s note.

While K18 is an Oxycodone tablet, it is NOT an OxyContin tablet. While they contain the same active ingredient (Oxycodone Hydrochloride), there is a subtle difference between the two:

  • Oxycodone: Immediate release for irregular, severe pain management.[2] The duration of effects from one tablet lasts from 3 to 6 hours.
  • OxyContin: Extended release for pain severe enough to require continuous medication (24 hours/day) for long-term treatment for which there is no alternative.[3] The duration of effects from one tablet lasts 12 hours, and two can be taken per day so long as they are taken 12 hours apart.

K 18 pills are manufactured as tablets rather than capsules. The tell-tale line scored down the middle makes it easier to break in half. Compared with capsules, tablets are generally more inexpensive, durable, splittable, and chewable.

At 5mg, they are the smallest of immediate-release Oxycodone dosages. Other pharmaceutical companies’ manufactured immediate-release Oxycodone tablets can run as high as 10, 15, 20, and 30 mg strengths.[4]

Similarly, extended-release Oxycontin tablets can run as high as 10, 15, 20, 30, 40, 60, and 80 mg strength.[5] As the strength increases, the more powerful the effect of the drug on your body. Take with extreme caution under the supervision of your prescribing physician.

K 18 Pill: What Kind of Pill Is This?Mechanism of Action

Oxycodone hydrochloride attaches to specific receptors in your brain called muopioid receptors. These receptors are extremely sensitive to hormones like endorphins. They block pain signals from reaching your brain.

Dopamine is released naturally during stress, pain, or pleasure. It works by blocking pain signals from your nerves and flooding your reward centers with pleasure. As we naturally wish to avoid pain, our body activates a reward for doing good things, with no barometer for what is truly healthy.

That’s why working out and running are associated with dopamine release. You may experience some physical pain but these activities keep your body healthy.

Other ways to release dopamine or positive endorphins include sex, breastfeeding, and eating.[6] The subjective experience of taking Oxycodone is similar to the endorphin release of these prior activities.

Identifying a Pill With K 18 Imprinted

K 18 painkiller pills are circular, white, and imprinted with the alphanumeric code “K 18” across the face. There is a line scored down the middle, which can aid in splitting the pill in half if it is part of your prescription. The “K” is on the left side of the bisecting line, and the “18” is on the right side.

It is a Schedule II prescription drug. The active ingredient is oxycodone hydrochloride, formulated with inactive ingredients, including lactose monohydrate, corn starch, microcrystalline cellulose, silicon dioxide, sodium starch glycolate type A potato, and stearic acid.[7]

Oxycodone works by binding to the mu-opioid receptors in the central nervous system, which blocks pain signals with pleasure hormones. Abusing these pills can have significant long-term consequences with a high potential for addiction and may have to involve professional drug rehabilitation.

What are the Uses of a Pill WIth K 18 On It?

K 18 pills are a schedule II class of opioid pain medications only to be used to treat moderate to severe pain. The FDA has ruled that no one can possess K 18 pills without a doctor’s prescription.

There must be a valid medical reason within the discretion of a supervisory treatment team to use K 18 to treat moderate to severe pain. This is not a general maintenance analgesic like ibuprofen. Addiction can set in quickly, even within just a few days. Take it with extreme caution and only as prescribed by your physician.

Side Effects You Should Be Aware Of

Oxycodone carries a high risk of dependence and misuse. Those with a history of drug abuse should carefully consider the effects of oxycodone before taking it. Discuss your concerns with your attending physician.

Immediate Effects of the K18 Pill:[8]

  • Pain relief
  • Feelings of relaxation
  • Reduced anxiety
  • Increased sedated, hypnotic state

Possible Adverse Effects of the K18 Pill:[9]

  • Nausea, stomach cramps, and vomiting
  • Constipation and loss of appetite
  • Drowsiness, flushing, sweating, and dry mouth
  • Weakness, headache, and dizziness/drowsiness
  • Itching, rash, hives, and swelling of the face, throat, or limbs
  • Decreased breathing rate and/or difficulty swallowing
  • Reduced blood pressure
  • Irregular heartbeat
  • Coma
  • Seizure

Frequently Asked Questions About Oxycodone

Below are some of the most frequently asked questions surrounding Oxycodone.

Oxycodone is the active painkiller ingredient in many different brand-name drugs. Oxycontin is the extended-release version of Oxycodone and is often used synonymously.

Some other oxycodone drugs include Endocet, Magnacet, Narvox, Percocet, Perloxx, Primalev, Roxicet, Roxicodone, Roxilox, Tylox, Xartemix XR, and Xolox.

Street names for Oxycodone are Hillbilly Heroin, Kicker, OC, Ox, Roxy, Perc, and Oxy.

Yes. Oxycodone is an opioid. It binds to receptors in the brain called endogenous opioid receptors. You will feel an “endorphin” high while taking it, similar to but much stronger than the “high” you feel after working out, running, having sex, breastfeeding, or eating.

There is a high potential for addiction if prescription abuse occurs. Talk to your attending physician for more details.

Do not drink alcohol while taking oxycodone. 

Both drugs depress the central nervous system, which slows down brain activity and impairs vital functions such as breathing, heart rate, and blood pressure. If your breathing rate gets too low, you won’t be able to oxygenate your blood, which can lead to death.

Taking both alcohol and oxycodone can intensify the individual effects of each drug. Your body’s natural defenses will be overwhelmed, and your liver will have to work extra hard to clean all the toxins out of your system. Liver damage or failure can occur.

No. K 18 pills are by prescription only. Contact your healthcare provider for more details.

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[1] National Institutes of Health. (n.d.). DailyMed – oxycodone hydrochloride tablet. U.S. National Library of Medicine. Retrieved from on July 27, 2023

[2][3][4][5] T;, S. N. T. (n.d.). Oxycodone. National Center for Biotechnology Information. Retrieved from on July 27, 2023

[6] Sprouse-Blum, A. S., Smith, G., Sugai, D., & Parsa, F. D. (2010, March). Understanding endorphins and their importance in pain management. Hawaii medical journal. Retrieved from on July 27, 2023

[7] K 18 pill white round – pill identifier. (n.d.). Retrieved from on July 27, 2023

[8][9] U.S. National Library of Medicine. (n.d.). Oxycodone: Medlineplus drug information. MedlinePlus. Retrieved from on July 27, 2023

Last medically reviewed August 11, 2023.