What does XR or ER mean after a drug name?

Medically reviewed by Drugs.com. Last updated on April 11, 2022.

Official answer

by Drugs.com

XR or ER is short for extended-release which means the pill is formulated so that the drug is released slowly over time.

This has the advantage of taking pills less often and there may be fewer side-effects as the levels of the drug in the body are more consistent in extended-release formulations.

Examples of extended-release drugs include:

• Effexor XR
• Nucynta ER
• Ultram ER
• Xanax XR

Related: Medical Abbreviations on Pharmacy Prescriptions

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Drug information

• Effexor XR
• Xanax XR
• Nucynta ER
• Ultram ER

Related support groups

• Effexor XR (107 questions, 602 members)
• Xanax XR (23 questions, 92 members)
• Nucynta ER (2 questions, 34 members)
• Ultram ER (1 questions, 14 members)

Medical Disclaimer