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.
- Both are benzodiazepines.
- Both work quickly 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.
- Both can cause dangerous withdrawal, including seizures, if stopped abruptly, so both must be tapered slowly with a prescriber.
- Both are sedating.
- Both are Schedule II controlled substances, a 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.
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 |
The first difference is duration. Lorazepam is intermediate-acting, and clonazepam is long-acting. Clonazepam gives the steadiest and longest coverage, while lorazepam's effect is shorter.
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. That is sometimes why a prescriber chooses it, particularly for older adults or for people with liver concerns.
The third difference is approved uses. Lorazepam is approved for anxiety, for anxiety associated with depression, and for the short-term relief of anxiety. Clonazepam is approved for panic disorder and for certain seizure disorders.
Side effects compared
The side effects of these two overlap closely, because they belong to the same class. Both are sedating, and both can cause drowsiness, tiredness, and slowed thinking or coordination. Both can cause physical dependence and tolerance with regular use.
The practical differences trace back to duration and metabolism. Lorazepam's shorter action can mean somewhat more rebound anxiety between doses, meaning anxiety that returns as the dose fades, while clonazepam's longer action tends to feel steadier. With both, 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. Neither is a long-term treatment for sleep problems, even though both can make people drowsy.
Weight change is not a defining feature of either drug. Sexual side effects are not a defining feature either, and neither is known for them the way SSRIs can be. Anything bothersome is worth raising with a prescriber.
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, such as in panic disorder, where consistent coverage through the day is useful.
A clinician might choose lorazepam when a somewhat shorter action is wanted, or when its simpler metabolism is an advantage. That can matter for older adults or for people with liver concerns, since lorazepam is less affected by liver problems and some drug interactions.
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, while lorazepam acts for a shorter time and has a simpler metabolism. That is a decision to make 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.
- U.S. Food and Drug Administration. Lorazepam prescribing information.
- U.S. Food and Drug Administration. Clonazepam prescribing information.
- MedlinePlus, U.S. National Library of Medicine.
- National Institute of Mental Health. Mental health medications.
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.
This guide is for general education. It is not medical advice and is not a substitute for evaluation, diagnosis, or treatment by a qualified clinician. Never start, stop, or change a medication without talking to your prescriber. If you are in crisis or thinking about harming yourself, call or text 988 in the U.S. to reach the Suicide and Crisis Lifeline.