Side Effects of Lorazepam: Common, Serious, and Long-Term
The common and serious side effects of lorazepam (Ativan), how it affects the body and mind, the dangers of combining it with alcohol, the risks of dependence and withdrawal, and how to use this benzodiazepine safely.
Clinically reviewed by Dr. Ponlawat Pitsuwan, Physician and Addiction Medicine Specialist, Phuket Island Rehab.
Lorazepam (brand name Ativan) is a benzodiazepine used for anxiety, insomnia, and certain other conditions, and like all benzodiazepines it has a range of side effects. The most common are drowsiness, dizziness, weakness, unsteadiness, and impaired coordination, along with memory and concentration problems. More serious but less common effects can include severe drowsiness or confusion, slowed or difficult breathing, especially when combined with alcohol or opioids, paradoxical reactions such as agitation or aggression, low blood pressure, and, rarely, allergic reactions. Lorazepam is dangerous when combined with alcohol or other sedatives, which can cause life-threatening respiratory depression. Beyond immediate side effects, its most important risks are tolerance, physical dependence, and addiction with regular use, and a dangerous withdrawal syndrome, including the risk of seizures, if it is stopped suddenly. For these reasons, lorazepam should be used at the lowest effective dose for the shortest necessary time, taken exactly as prescribed, never mixed with alcohol, and never stopped abruptly after regular use.
About lorazepam
Lorazepam, sold under the brand name Ativan, is a benzodiazepine, a class of sedative medications that calm the central nervous system. It is prescribed for anxiety, sometimes for short-term insomnia related to anxiety, for sedation before medical procedures, and for certain other conditions including the emergency treatment of prolonged seizures. It works by enhancing the effect of a calming brain chemical called GABA, which reduces the activity of the nervous system and produces an anti-anxiety, sedating, and muscle-relaxing effect. Like all medications, and like all benzodiazepines in particular, lorazepam has a range of side effects that anyone taking it should understand.
Understanding the side effects of lorazepam matters for two reasons. First, the immediate side effects, mostly related to its sedating action, affect how a person feels and functions and can have safety implications, such as for driving. Second, and more importantly, the most significant risks of lorazepam are not the everyday side effects but its potential for dependence, addiction, and a dangerous withdrawal, along with its danger in combination with alcohol and other depressants. This article covers the common and serious side effects, the dangers of combinations, and the longer-term risks, so that anyone taking lorazepam can use it as safely as possible and recognise when something needs medical attention.
Common side effects
The most common side effects of lorazepam stem from its sedating, central-nervous-system-calming action. Drowsiness and sedation are the most frequent, along with dizziness, tiredness, weakness, and a feeling of being unsteady or off balance, which can increase the risk of falls, particularly in older people. Lorazepam commonly impairs coordination and reaction time, and it can affect memory and concentration, sometimes causing forgetfulness or difficulty thinking clearly. Some people feel a degree of confusion or mental cloudiness, especially at higher doses or when starting the medication. These effects are generally more pronounced at the beginning of treatment and at higher doses.
Because of these effects, lorazepam can impair the ability to drive or operate machinery and to perform tasks requiring alertness, and people are usually advised to be cautious until they know how it affects them. Other relatively common side effects can include a dry mouth, blurred vision, changes in appetite, headache, and digestive upset. While these common side effects are usually not dangerous in themselves, they can affect daily functioning and safety, which is part of why lorazepam is typically prescribed at the lowest effective dose and, where possible, for short periods. Anyone troubled by side effects should speak to their doctor rather than adjusting the medication themselves.
| Category | Side effects |
|---|---|
| Common | Drowsiness, dizziness, weakness, unsteadiness, fatigue |
| Cognitive | Memory and concentration problems, confusion, forgetfulness |
| Other common | Dry mouth, blurred vision, headache, appetite changes |
| Serious | Severe drowsiness or confusion, slowed or difficult breathing |
| Paradoxical | Agitation, restlessness, aggression, excitement |
| Rare / serious | Low blood pressure, allergic reaction, fainting |
Serious side effects and combinations
Less common but more serious side effects of lorazepam require prompt medical attention. These include severe drowsiness or confusion, slowed, shallow, or difficult breathing, severe weakness or unsteadiness leading to falls, and signs of a serious allergic reaction such as swelling, rash, or difficulty breathing. Some people experience paradoxical reactions, in which instead of calming, the drug causes agitation, restlessness, irritability, aggression, excitement, or, rarely, hallucinations, an effect more common in older adults and children, and a reason to contact a doctor if behaviour changes in this way. Lorazepam can also lower blood pressure and, particularly in vulnerable people, cause fainting.
The most dangerous situation involving lorazepam is its combination with other substances that depress the central nervous system, above all alcohol and opioids, but also other sedatives and sleep medications. Because lorazepam already slows the nervous system and breathing, combining it with these multiplies the effect and can cause severe respiratory depression, where breathing becomes dangerously slow or stops, which can be fatal. This combination is a major cause of overdose deaths, and it is why lorazepam should never be taken with alcohol or other depressants, and why prescribers are especially cautious about co-prescribing it with opioids. Any sign of extreme sedation, slowed breathing, or unresponsiveness in someone who has taken lorazepam, especially with other substances, is a medical emergency.
Dependence, addiction, and withdrawal
Beyond its immediate side effects, the most important risks of lorazepam are tolerance, physical dependence, and addiction. With regular use, often within weeks, the body adapts: tolerance can develop, so that the same dose has less effect, and physical dependence can develop, meaning the body comes to rely on the drug and reacts with withdrawal when it is reduced or stopped. Lorazepam also carries a real potential for misuse and addiction, particularly when taken in higher doses, more often than prescribed, or for its calming or euphoric effect. These risks are the main reason lorazepam is generally recommended for short-term use rather than long-term, ongoing treatment.
The flip side of dependence is withdrawal, which for benzodiazepines like lorazepam is genuinely serious. Stopping lorazepam suddenly after regular use can cause a withdrawal syndrome that includes rebound anxiety and insomnia, agitation, sweating, tremor, and, importantly, the risk of seizures, which can be life-threatening. This is why lorazepam should never be stopped abruptly after regular use; it must be tapered gradually under medical supervision. The seriousness of benzodiazepine withdrawal is one of the most important things to understand about lorazepam, and it means that coming off the medication needs to be planned and managed with a doctor, not attempted suddenly or alone.
Using lorazepam safely
Given this profile, lorazepam can be used safely with appropriate care. The key principles are to take it only exactly as prescribed, at the lowest effective dose and for the shortest necessary time, and never to increase the dose or take it more often without medical advice. It should never be combined with alcohol or other sedating substances, and prescribers should be told about all other medications, especially opioids. Because of its effects on alertness and coordination, caution is needed with driving and other demanding tasks, particularly when starting or increasing it. Older adults need particular care, as they are more sensitive to its sedating and balance effects and the risk of falls.
It is also important to plan ahead for stopping. Because of the dependence and withdrawal risks, coming off lorazepam should be done gradually with medical guidance rather than suddenly, and long-term use should be reviewed regularly with a doctor. Anyone who finds they are needing more, taking it for longer than intended, or relying on it should discuss this with their prescriber, as there are often safer, non-addictive alternatives for ongoing anxiety, such as certain antidepressants and therapy. Used thoughtfully, for the right reasons, at the right dose, for a limited time, and under medical oversight, lorazepam’s side effects and risks can be managed, while misuse or careless use makes them far more likely.
When use has become more than the prescription
Because lorazepam carries a real risk of dependence and addiction, it is worth recognising the warning signs that use has become a problem. These include needing more for the same effect, taking it in higher doses or more often than prescribed, taking it for its calming or sedating effect rather than as directed, running out early, feeling unable to cope without it, combining it with alcohol or other substances, seeking it from more than one source, and experiencing rebound anxiety, insomnia, or withdrawal between doses or when trying to stop. These signs point to a developing problem with what is a powerful benzodiazepine.
If you or someone you love has become dependent on lorazepam or another benzodiazepine, the most important safety point is not to stop suddenly, because withdrawal can cause seizures and be dangerous. Coming off should be done gradually under medical supervision, ideally through a medically supervised detox that manages the taper safely. Benzodiazepine dependence and addiction are treatable, and treatment can also address the underlying anxiety, often with safer approaches. Reaching out for help is a positive step, and with proper support people recover and find better, lasting ways to manage anxiety and stay well. The side effects and risks of lorazepam are real, but they are manageable with the right care and, where needed, the right help.
Summary
Lorazepam (Ativan) is a benzodiazepine used for anxiety, insomnia, and certain other conditions, and like all benzodiazepines it has a range of side effects. The most common are drowsiness, dizziness, weakness, unsteadiness, and impaired coordination, along with memory and concentration problems. More serious but less common effects can include severe drowsiness or confusion, slowed or difficult breathing, especially when combined with alcohol or opioids, paradoxical reactions such as agitation or aggression, low blood pressure, and, rarely, allergic reactions. Lorazepam is dangerous when combined with alcohol or other sedatives, which can cause life-threatening respiratory depression. Beyond immediate side effects, its most important risks are tolerance, physical dependence, and addiction with regular use, and a dangerous withdrawal syndrome, including the risk of seizures, if stopped suddenly. Lorazepam should be used at the lowest effective dose for the shortest necessary time, taken exactly as prescribed, never mixed with alcohol, and never stopped abruptly after regular use.
As Dr. Ponlawat Pitsuwan, addiction medicine specialist at Phuket Island Rehab, puts it, “With lorazepam, the side effects patients notice, the drowsiness, the unsteadiness, the foggy memory, are real but usually manageable. The risks I worry about most are the ones they do not notice until later: how quickly dependence can build, how dangerous it is mixed with alcohol or an opioid, and how serious the withdrawal can be if they ever stop suddenly. Used briefly and carefully it is a useful drug, but it demands respect, and it should never be stopped abruptly.”
Frequently asked questions
What are the common side effects of lorazepam?
The most common side effects stem from its sedating action and include drowsiness, dizziness, tiredness, weakness, and a feeling of unsteadiness, which can increase the risk of falls. It commonly impairs coordination and reaction time and can affect memory and concentration, sometimes causing forgetfulness or mental cloudiness. Other common effects include dry mouth, blurred vision, headache, and appetite changes. These are usually more pronounced at the start of treatment and at higher doses, and they can impair driving and tasks requiring alertness.
What are the serious side effects of lorazepam?
Less common but serious effects include severe drowsiness or confusion, slowed, shallow, or difficult breathing, severe unsteadiness leading to falls, and signs of a serious allergic reaction. Some people have paradoxical reactions such as agitation, restlessness, aggression, or excitement instead of calming, more common in older adults and children. It can also lower blood pressure and cause fainting. Any slowed breathing, extreme sedation, or unresponsiveness, especially with alcohol or opioids, is a medical emergency requiring immediate help.
Is it dangerous to mix lorazepam with alcohol?
Yes, very. Both lorazepam and alcohol depress the central nervous system and slow breathing, so combining them multiplies the effect and can cause severe respiratory depression, where breathing becomes dangerously slow or stops, which can be fatal. The same applies to combining lorazepam with opioids or other sedatives. This combination is a major cause of overdose deaths, which is why lorazepam should never be taken with alcohol or other depressant substances.
Can lorazepam cause dependence?
Yes. With regular use, often within weeks, lorazepam can cause tolerance, so the same dose has less effect, and physical dependence, so the body relies on it and reacts with withdrawal when it is reduced or stopped. It also carries a real potential for misuse and addiction, especially at higher doses or when used for its calming effect. These risks are the main reason lorazepam is generally recommended for short-term rather than long-term use, at the lowest effective dose.
What happens if you stop lorazepam suddenly?
Stopping lorazepam suddenly after regular use can cause a withdrawal syndrome that includes rebound anxiety and insomnia, agitation, sweating, tremor, and, importantly, the risk of seizures, which can be life-threatening. This is why it should never be stopped abruptly but tapered gradually under medical supervision. The seriousness of benzodiazepine withdrawal means coming off the medication must be planned and managed with a doctor, ideally through a medically supervised detox, rather than attempted suddenly or alone.
How can lorazepam be used safely?
Take it only exactly as prescribed, at the lowest effective dose and for the shortest necessary time, and never increase the dose or take it more often without medical advice. Never combine it with alcohol or other sedating substances, and tell prescribers about all other medications, especially opioids. Be cautious with driving and demanding tasks, and take particular care in older adults. Plan ahead for stopping by tapering gradually with a doctor, and review long-term use regularly, as safer alternatives often exist for ongoing anxiety.
Sources
Food and Drug Administration (FDA). Lorazepam (Ativan) Prescribing Information and Boxed Warning. https://www.fda.gov/drugs
National Library of Medicine (MedlinePlus). Lorazepam. https://medlineplus.gov/druginfo/meds/a682053.html
National Health Service (NHS). Lorazepam. https://www.nhs.uk/medicines/lorazepam/
National Institute on Drug Abuse (NIDA). Prescription CNS Depressants DrugFacts. https://nida.nih.gov/publications/drugfacts/prescription-cns-depressants
Substance Abuse and Mental Health Services Administration (SAMHSA). Benzodiazepines. https://www.samhsa.gov/
National Institute of Mental Health (NIMH). Anxiety Disorders. https://www.nimh.nih.gov/health/topics/anxiety-disorders
Side effects of lorazepam — key entities and related terms
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