Ketorolac tromethamine is a powerful anti-inflammatory painkiller used for the short-term management of moderately severe acute pain, typically after surgery. It belongs to the NSAID class (the same family as ibuprofen and naproxen) but is significantly stronger, delivering pain relief at a level comparable to opioids. Its total use is limited to five days or fewer, making it a targeted tool for intense but temporary pain rather than an everyday pain reliever.
What Ketorolac Treats
Ketorolac is approved specifically for moderately severe acute pain that would otherwise require an opioid. The most common setting is post-surgical recovery, where patients need strong pain control in the first few days after a procedure. It’s used after orthopedic surgeries, abdominal surgeries, dental extractions, and a range of other operations where the initial pain is intense but expected to resolve quickly.
What ketorolac is not for matters just as much. It is not indicated for minor aches, headaches, or chronic conditions like arthritis or back pain. The FDA label explicitly states it is “NOT indicated for minor or chronic painful conditions.” This distinction exists because the risks of ketorolac, particularly to the stomach, kidneys, and cardiovascular system, outweigh the benefits for pain that can be managed with milder options.
How It Works in the Body
Ketorolac reduces pain and inflammation by blocking an enzyme called cyclooxygenase, or COX. This enzyme helps produce prostaglandins, chemical messengers that trigger inflammation, swelling, and pain signaling at injury sites. By suppressing prostaglandin production, ketorolac dials down both the inflammatory response and the pain that comes with it. This same mechanism is why it must be used cautiously: prostaglandins also play protective roles in the stomach lining, kidneys, and blood flow regulation, so blocking them aggressively can cause problems in those areas.
How It Reduces Opioid Use After Surgery
One of ketorolac’s most valued roles in modern medicine is as an opioid-sparing tool. Because it delivers pain relief comparable to opioids without the risk of addiction, sedation, or respiratory depression, surgeons and anesthesiologists often use it to reduce how many opioid pills a patient needs during recovery.
A randomized controlled trial published in the Journal of Arthroscopy studied patients recovering from knee meniscus surgery. One group received only oxycodone-acetaminophen (a standard opioid prescription). The other group received ketorolac intravenously during surgery and orally afterward, with opioids available only as a backup. Over the first five days, the ketorolac group reported significantly lower pain scores (a 13-point reduction on a 100-point pain scale) and consumed nearly 5 fewer morphine-equivalent doses per time point. In practical terms, patients needed substantially fewer opioid pills and still experienced better pain control.
Forms and Routes of Administration
Ketorolac is available in three forms: injection (given into a vein or muscle), oral tablets, and a nasal spray. The injection is typically given first, often in the hospital or recovery room immediately after surgery. Oral tablets are only approved as a continuation of the injectable form, not as a standalone prescription. You won’t receive ketorolac tablets without having started on the injection first.
The nasal spray version offers a non-injection option for patients who need continued dosing outside a hospital setting. It works the same way and carries the same five-day limit. For older adults, the nasal spray requires particular caution because age-related changes in kidney, heart, and stomach function increase the risk of side effects.
The Five-Day Limit
Ketorolac has one of the strictest time limits of any commonly prescribed painkiller. The total combined duration across all forms (injection, oral, and nasal) must not exceed five days. This isn’t a soft guideline. It’s a hard ceiling built into the drug’s labeling because the risk of serious gastrointestinal bleeding, kidney damage, and cardiovascular events rises sharply with longer use. Ketorolac is a potent inhibitor of prostaglandin production, and the protective functions those prostaglandins serve in the gut and kidneys can only be suppressed for so long before real harm occurs.
Who Should Not Take Ketorolac
Several groups of people should avoid ketorolac entirely. It is contraindicated during labor and delivery because blocking prostaglandins can disrupt blood flow to the fetus and weaken uterine contractions, raising the risk of hemorrhage. Women trying to conceive are also advised against it, since prostaglandin inhibition can impair fertility.
People with impaired kidney function or a history of kidney disease need extra caution. Ketorolac’s strong prostaglandin-blocking activity can reduce blood flow to the kidneys, potentially worsening existing damage. The same concern applies to patients with a history of stomach ulcers or GI bleeding, since the drug strips away the stomach’s protective lining. Breastfeeding mothers should weigh the risks carefully, as adequate safety data for nursing infants is lacking.
Use in Children
Ketorolac’s FDA labeling for the oral and standard injectable forms states it is not indicated for pediatric patients. However, the injectable form has been used in children 2 years and older in clinical practice, based on studies showing safety and efficacy at weight-based doses. The typical pediatric IV dose ranges from 0.5 to 1 mg per kilogram of body weight, given every 6 hours, with a maximum of 15 mg per dose. Research on infants suggests the same weight-based range given every 6 to 8 hours can be appropriate, though use in newborns younger than 21 days old or those born significantly premature is not recommended.
What to Expect When You’re Prescribed Ketorolac
If you receive ketorolac, it will almost always start as an injection, either in your IV line or as a shot in a large muscle. Pain relief typically begins within 30 minutes and can last 4 to 6 hours. If your surgeon decides you need continued dosing after leaving the hospital, you may be sent home with a short supply of oral tablets or a nasal spray, with clear instructions not to exceed the five-day total.
During those five days, you should watch for signs of stomach irritation (nausea, dark or bloody stools, stomach pain), decreased urination or swelling in the legs (which can signal kidney stress), and any unusual bruising or bleeding. These side effects are uncommon in short courses but are the reason the drug carries such strict limits. Ketorolac is a remarkably effective painkiller for the narrow window it’s designed for, and staying within that window is what keeps it safe.