Ativan vs Klonopin
How lorazepam and clonazepam compare, two benzodiazepines used for anxiety and panic.
How they're similar
Lorazepam and clonazepam have a great deal in common. They are close relatives, and most of what is true of one is true of the other.
- Both are benzodiazepines.
- Both work quickly, within about an hour, by strengthening GABA, the brain's main calming chemical messenger.
- Both treat anxiety and panic.
- Both carry two FDA boxed warnings, the agency's most serious warning. One is about abuse, dependence, and withdrawal. The other is about the danger of combining them with opioids.
- Both can cause physical dependence and tolerance with regular use, even when taken exactly as prescribed.
- Both can cause dangerous withdrawal, including seizures, if stopped abruptly, so both must be tapered slowly with a prescriber.
- Both are sedating, and both can cause drowsiness, slowed thinking, reduced coordination, and memory problems, more so at higher doses.
- Both are Schedule IV controlled substances, a federal category for medications with accepted medical use and a recognized potential for misuse and dependence.
- Both are generally used short-term, with SSRIs or SNRIs first-line for ongoing anxiety.
- Both are inexpensive generics that have been available for years.
These shared cautions are real, and they are also manageable when treatment is planned and supervised. They are a reason for care, not for alarm.
How they differ
For two drugs in the same class, the differences are narrow. They come down to duration, how the body clears the drug, and approved uses. The table below sums up the core points, with more detail underneath.
| Lorazepam (Ativan) | Clonazepam (Klonopin) | |
|---|---|---|
| Drug class | Benzodiazepine | Benzodiazepine |
| Duration of effect | Intermediate-acting | Long-acting |
| How the body clears it | Processed in a way less affected by liver problems and some drug interactions | Processed through the liver, more open to those factors |
| Rebound between doses | Somewhat more rebound, shorter effect | Less rebound, steadier effect |
| FDA-approved uses | Anxiety, anxiety associated with depression, short-term relief of anxiety | Panic disorder, certain seizure disorders |
| Dosing pattern | Often dosed more than once a day | Often fewer doses across the day |
The first difference is duration. Lorazepam is intermediate-acting, and clonazepam is long-acting. Both start working within about an hour, so neither has an edge on speed. The difference is how long a dose holds. Clonazepam gives the steadiest and longest coverage from a single dose. Lorazepam's effect lasts a useful while, longer than a very short-acting benzodiazepine, but it does not stretch as far as clonazepam's. In day-to-day terms, that can mean lorazepam is dosed more than once a day, while clonazepam may cover the day with fewer doses. It can also mean lorazepam shows somewhat more rebound anxiety between doses, meaning anxiety that returns as the dose fades, while clonazepam feels more level.
The second difference is how the body clears the drug. Lorazepam is processed in a way that is less affected by liver problems and by some drug interactions. The body breaks it down through a simpler route, so its level is less likely to swing because of liver function or other medications. Clonazepam is processed more through the liver in a way that is more open to those factors. This is often why a prescriber chooses lorazepam for older adults or for people with liver concerns, where a more predictable level matters and where extra sedation from a drug interaction is a particular worry.
The third difference is approved uses. Lorazepam is approved for anxiety, for anxiety associated with depression, and for the short-term relief of anxiety symptoms. Clonazepam is approved for panic disorder and for certain seizure disorders. In practice both are used for anxiety and panic, and the seizure use of clonazepam is a separate matter handled by a prescriber. A small practical point, clonazepam also comes as an orally disintegrating tablet that dissolves in the mouth.
Side effects compared
The side effects of these two overlap closely, because they belong to the same class. Both are sedating. Both can cause drowsiness, tiredness, lightheadedness, reduced coordination, and, especially at higher doses, slowed thinking, memory problems, and slurred speech. Both can cause physical dependence and tolerance with regular use, meaning the body adjusts so that the same dose may work less well over time.
The practical differences trace back to duration and metabolism. Lorazepam's shorter action can mean somewhat more rebound anxiety between doses and a sense that the effect has worn off sooner. Clonazepam's longer action tends to feel steadier across the day. Lorazepam's simpler metabolism makes its level a bit more predictable when liver function is reduced or when other medications are involved. Older adults are more affected by both drugs, with a higher chance of falls, confusion, and memory problems, which is part of why a more predictable drug is sometimes preferred for them. With either drug, stopping abruptly can cause dangerous withdrawal, including seizures, so both are tapered slowly with a prescriber.
Sleep, weight, and sexual effects
Both medications are sedating, and that sedation can carry into sleep. Some people notice the calming effect helps them settle at night, but neither drug is a long-term treatment for sleep problems. Sleep that depends on a benzodiazepine tends to become a dependence issue rather than a fix, which is one more reason these drugs are usually used short-term.
Weight change is not a defining feature of either drug. Neither typically affects appetite the way some other psychiatric medications can. Sexual side effects are not a defining feature either, and neither is known for them the way SSRIs are. Anything bothersome in any of these areas is worth raising with a prescriber, since other factors, including anxiety itself, can play a part.
Why a clinician might choose one over the other
Because the two are close, the choice often comes down to duration and metabolism.
A clinician might choose clonazepam for steady, longer coverage from fewer doses. In panic disorder, where anxiety can build through the day, consistent coverage is useful, and clonazepam's long action means less rebound between doses. Its gentler fall-off can also make a future taper somewhat easier to plan.
A clinician might choose lorazepam when a somewhat shorter action fits better, or when its simpler metabolism is an advantage. That metabolism matters most for older adults and for people with liver concerns, since lorazepam's level is less affected by liver problems and by some drug interactions. For someone on several medications, fewer interactions can mean fewer surprises in sedation. Lorazepam's approval for anxiety associated with depression also makes it a familiar fit when anxiety sits alongside low mood.
Prior response matters too. Someone who has done well on one of these drugs has a reasonable reason to stay with it. And for either drug, the larger question is often whether a benzodiazepine is the right tool at all. Neither is a long-term solution for anxiety.
The bottom line
Lorazepam and clonazepam are in the same class, with the same cautions, and the choice comes down to duration and how the body clears the drug. Clonazepam gives steadier, longer coverage from fewer doses, with less rebound. Lorazepam acts for a shorter time and has a simpler metabolism that is less affected by liver problems and drug interactions, which can suit older adults. Whether a benzodiazepine is the right tool at all, and which one fits, is a decision to make with a prescriber.
Common questions
Is Ativan or Klonopin stronger? Neither is simply stronger. They differ in duration, not in raw power. Doses are not interchangeable, and a prescriber matches the drug and dose to the situation. Clonazepam's longer action can make it feel more constant, while lorazepam's effect is felt over a shorter window.
Which is better for older adults? Lorazepam is often preferred for older adults, because its simpler metabolism makes its level more predictable when liver function is reduced or when other medications are involved. That said, both benzodiazepines carry extra risk of falls, confusion, and memory problems in older adults, so the decision and the dose belong with a prescriber.
Can you switch from Ativan to Klonopin? Yes, this is a recognized step. A prescriber sometimes moves a person to clonazepam for steadier coverage or to make an eventual taper smoother. The switch needs to be planned and supervised, since the two drugs are not dosed one for one and the change has to be timed carefully.
Which one is harder to stop? Both require a slow, planned taper, and neither should be stopped suddenly. Lorazepam's shorter action means the body can feel the change a bit sooner, while clonazepam's long action makes its level fall more gently. The schedule for either taper depends on the dose and how long the drug has been taken, and it belongs with a prescriber.
Sources
This guide draws on current prescribing information and public health references. It is reviewed for clinical accuracy and updated as guidance changes.
Some clinicians and practices don't prescribe controlled substances like these. Why some practices don't prescribe these at shrinkMD.
Managing a medication needs a prescriber
Any psychiatric medication has to be started and adjusted by a clinician who can follow you over time. If you don't have a prescriber, our guides section explains the options, including in-person care and telepsychiatry, and how to choose between them.