Stadol (butorphanol) provides pain relief for roughly 3 to 4 hours per dose. The drug itself stays in your system longer than that, with a half-life of about 2 to 5 hours in healthy adults, meaning it takes the body around 12 to 24 hours to fully clear it. How long both the effects and the drug itself last depends on how it’s given and your overall health.
How Long Pain Relief Lasts by Route
Stadol can be given intravenously (IV), as an intramuscular (IM) injection, or as a nasal spray. The route matters for how quickly it kicks in, but the duration of pain relief is similar across all three.
- IV injection: Pain relief begins within minutes. Peak effect hits within 30 minutes. Relief lasts 3 to 4 hours.
- IM injection: Onset within 15 minutes. Peak effect between 30 and 60 minutes. Relief lasts 3 to 4 hours.
- Nasal spray: Onset within 15 minutes. A second spray can be used 60 to 90 minutes after the first if pain persists, but only if your prescriber has specifically approved it. Doses are generally spaced every 3 to 4 hours.
That 3 to 4 hour window is defined as the point when pain returns to its pre-treatment level or the time at which most patients need another dose.
How Long It Stays in Your Body
Pain relief fading doesn’t mean the drug is gone. After an IV dose, butorphanol’s blood levels drop in two phases. The first phase (distribution through the body) happens fast, with a half-life of about 6 minutes. The second phase (actual breakdown and removal) has a half-life of roughly 2 to 3.5 hours in younger, healthy adults. For the nasal spray, the half-life averages around 4.7 hours.
The liver does most of the work breaking butorphanol down into inactive compounds. About 70 to 80% of the drug is eventually cleared through urine, with another 15% leaving through feces. Because the liver and kidneys are central to this process, anything that affects those organs changes how long the drug lingers.
Why It Lasts Longer in Some People
Several factors can significantly extend how long butorphanol stays active in your system.
Age Over 65
Older adults clear the drug more slowly. The average half-life rises by about 25%, from roughly 4.7 hours to 6.6 hours. This means each dose produces effects that last longer and build up more between doses. Prescribers typically space doses at least 6 hours apart for older patients instead of the usual 3 to 4.
Kidney Problems
In people with significantly reduced kidney function, the half-life approximately doubles to around 10.5 hours, and the body’s ability to clear the drug drops by about half. This means the drug can accumulate faster if doses aren’t adjusted.
Liver Problems
Liver impairment has the most dramatic effect. The half-life can roughly triple, reaching nearly 17 hours, while clearance drops by about half. Because the liver is responsible for breaking butorphanol down, any compromise to liver function keeps the drug circulating far longer than it would otherwise.
Side Effects and How Long They Last
The most common side effects, including drowsiness, dizziness, and nausea, generally track with the drug’s active window. You can expect them to be strongest around peak effect (30 to 60 minutes after a dose) and to fade as the drug wears off over the next few hours. Drowsiness tends to be the most noticeable effect and can make it unsafe to drive or operate machinery for several hours after a dose.
If you fall into one of the groups where the drug lasts longer (older adults, liver or kidney issues), these side effects can persist longer too. The sedation in particular can be more pronounced and longer-lasting, which is why lower and less frequent doses are used in these situations.
Withdrawal After Regular Use
Butorphanol is an opioid, and stopping it abruptly after regular use can trigger withdrawal symptoms. These can include restlessness, anxiety, muscle aches, sweating, nausea, vomiting, diarrhea, and trouble sleeping. The timeline varies depending on how long you’ve been using the medication and how quickly you stop, but symptoms generally begin within hours to a day after the last dose, reflecting the drug’s relatively short half-life. A gradual taper, rather than stopping all at once, reduces the intensity of withdrawal.