What Is A Lethal Dose Of Restoril (Temazepam)?

Restoril, known by its generic name as temazepam, is a benzodiazepine used to treat insomnia by enhancing brain chemicals that promote relaxation and sleep. While effective for sleep disorders when used as directed, understanding its safety limits is important for both people and healthcare providers. Questions about overdose potential become especially relevant given the drug’s widespread use and potential for misuse.

The lethal dose for Restoril is 1,963 milligrams per kilogram (mg/kg) in mice, 1,833 mg/kg in rats, and more than 2,400 mg/kg in rabbits. The average adult dose of Restoril is 15 mg, but doses can range between 7.5 mg and 30 mg. This means lethal doses in animal studies are hundreds of times higher than typical prescriptions, suggesting a relatively wide safety margin. However, real-world overdose risks increase significantly when Restoril is combined with alcohol or other depressants, or taken in much higher amounts than prescribed.

Learn more about the lethal doses of commonly abused drugs.

How A Lethal Dose Of Restoril Is Determined

Restoril is in a class of drugs called sedatives or hypnotics. Restoril is an effective medication in making the body fall asleep quicker and stay asleep longer. Not everyone who takes Restoril abuses it, but the body can build up a tolerance to the medication, which can lead to an increase in the dose and chemical dependency.

If a person ingests a high volume of Restoril, the body can respond with symptoms like:

• confusion
• coma
• reduced or absent reflexes
• respiratory depression
• hypotension
• loss of consciousness
• fainting

These symptoms can be treated and are not always fatal. There have been fatal cases where only Restoril was present in the body, but overdoses most often involve other substances such as depressants, including alcohol.

Mixing Restoril (Temazepam) With Opioids Can Have Lethal Consequences

The U.S. Food and Drug Administration (FDA) warns against combining Restoril and opioids due to serious and potentially fatal interactions. Both drugs are central nervous system depressants that slow down brain activity and breathing. When taken together, their effects amplify each other, creating dangerous suppression of vital functions. Mixing Restoril and opioids can result in heavy sedation, respiratory depression, coma, and in some cases death, even at prescribed doses.

The risks extend to other central nervous system depressants beyond just opioids. Other potentially fatal combinations include muscle relaxers, alcohol, and other sleeping medicines, which can compound Restoril’s sedating effects and lead to respiratory failure. These dangerous interactions can happen accidentally when people don’t realize they’re mixing depressants, or intentionally when someone uses multiple drugs to enhance their effects.

Other Factors That Affect The Fatal Dose Of Restoril

Several individual factors can significantly lower the amount of Restoril needed to cause fatal overdose. Age plays a major role, as older adults process medications more slowly and are more sensitive to benzodiazepines. Body weight, overall health, and tolerance levels also affect overdose risk, with smaller individuals and those with liver or kidney problems being more vulnerable. People with no tolerance to benzodiazepines may experience dangerous effects at doses that regular users might tolerate.

Underlying medical conditions can dramatically increase overdose risk even at prescribed doses. Respiratory problems like sleep apnea or COPD make people more susceptible to breathing difficulties from Restoril. Mental health medications can interact with Restoril and increase its effects. Additionally, crushing and snorting tablets bypasses the time-release design and floods the system with dangerous levels, potentially causing fatal overdose at much lower amounts than oral use.

If you or a loved one are battling addiction and need help, contact your primary care provider for guidance or reach out to the Substance Abuse and Mental Health Services Administration (SAMHSA).

Written by the Addiction Resource Editorial Staff