How Long Does Restoril (Temazepam) Stay in Your System?

Restoril (temazepam), which is prescribed as a short-term sleeping aid for people with insomnia, works by slowing activity in your brain. Because it can be habit-forming, it's typically prescribed for no more than 10 days.

The drug can be detected in your body from one to 90 days, depending on the type of detection test as well as other factors like dosage, age, weight, and metabolism.

Restoril is in a class of drugs called benzodiazepines, which are central-nervous-system depressants and Schedule IV controlled substances. When combined with other depressants or alcohol, or when taken in large dosages, Restoril can cause a loss of consciousness and respiratory failure, so it's important to know how long it remains in your system to avoid negative drug interactions.

How Long Does It Take to Feel the Effects?

Restoril is classified as a short- to intermediate-acting benzodiazepine. It begins to work in 10 to 20 minutes after you take a dose, with the levels peaking at about one and a half hours later.

It's recommended that you only take Restoril if you are able to stay in bed for seven to eight hours before you have to get up again as the medication will be affecting you during that time period.

The side effects from Restoril may include:

• Feeling groggy the next day
• Drowsiness
• Headache
• Dizziness
• Nervousness
• Nausea
• Lethargy
• Anxiety
• Depression
• Dry mouth

Though it's uncommon, you may also have instances of sleepwalking, which can include engaging in activities such as driving, cooking, talking on the phone, and having sex with no memory of having done these things. If you have side effects and they don't go away or they're severe, be sure to tell your doctor.

How Long Does Restoril Last?

The half-life of a drug is the time it takes for half the drug to be eliminated from your system. It takes five to seven half-lives to clear out 98% of a drug dose. The amount of time a benzodiazepine remains in your system depends partly on what type it is: ultra-short, short, intermediate, or long-acting. Ultra-short benzodiazepines have a half-life of fewer than five hours, while short- to intermediate-acting benzodiazepines like Restoril have a half-life from five to 24 hours. Long-acting benzodiazepines have a half-life exceeding 24 hours. The average half-life of Restoril is around 9 hours.

Restoril is metabolized by your liver with a half-life in two phases, one short and one long, and most of it is excreted in your urine. In general, the typical detection windows for benzodiazepines are as follows.

Urine

On average, a typical therapeutic dose of Restoril will appear positive on a urine drug screen, such as those done for employment purposes, for five days to a week. Heavier or longer use may create a positive urine test for weeks.

Blood

Restoril clears out of your bloodstream much faster than urine and is usually only detectable in blood for up to 24 hours.

Saliva

Restoril may be detectable in your saliva for 24 hours or more.

Hair

As with all drugs, Restoril can be detected in your hair starting two to three weeks after and for up to three months after your last dose.

False Positive Testing

There are some medications that may result in a false positive urine screen for Restoril. The antidepressant medication Zoloft (sertraline) and prescription non-steroidal anti-inflammatory drug Daypro (oxaprozin) reportedly can cause a false-positive urine test for benzodiazepines like Restoril.

If you are taking Restoril and need to take a drug screening for work, tell the testing laboratory so they can properly interpret your results. You may also want to let your employer or prospective employer know that you're taking Restoril ahead of time.

Factors That Affect Detection Time

How long Restoril is detectable in your body depends on many variables, including which kind of drug test is being used, your metabolism, weight, amount of body fat, hydration, how long you've been taking Restoril, and the amount of the drug taken.

Age

Your age can play a factor in the half-life of Restoril, with the average half-life being higher for healthy, elder adults than for healthy young adults.

Weight

Being overweight makes it more difficult for your body to eliminate Restoril, which can increase the half-life of the drug. 

Metabolism

People with a higher metabolism, which can depend on hydration, age, activity level, and other health conditions, tend to be able to excrete Restoril faster.

Alcohol Misuse

Combining alcohol and Restoril can result in a fatal overdose. Alcohol can increase Restoril's sedative effects as well as make it harder for your body to break down the drug.

Symptoms of Overdose

Since Restoril is habit-forming, it's important to take your prescription on the schedule and dosage your doctor prescribed. Misuse of the drug could result in an overdose, which can manifest with symptoms like:

• Confusion
• Dizziness
• Drowsiness
• Loss of consciousness
• Difficulty breathing

Allergic Reactions

It is also possible to develop a severe allergic reaction to Restoril. Call 911 or go to the nearest emergency room if you experience the following symptoms:

• Rash
• Hives
• Swelling of your face
• Hoarseness
• Difficulty breathing or swallowing

Drug Interactions

Avoid drinking alcohol, using street drugs, or taking opiates (such as codeine, hydrocodone, fentanyl, hydromorphone, meperidine, methadone, morphine, oxycodone, or tramadol) while taking Restoril as this increases your risk of developing life-threatening breathing problems, sedation, coma, or death.

Other drugs that can potentially cause negative interactions with Restoril include:

• Antihistamines like Benadryl (diphenhydramine)
• Digoxin
• Anxiety medications
• Medications for mental illness like antidepressants or antipsychotics
• Antiepileptics (for seizures)
• Medications to treat pain
• Sedatives
• Other sleeping pills
• Tranquilizers

Getting Help

It's important to taper off Restoril gradually and under the guidance of your doctor. If you suddenly stop taking Restoril, you may experience a variety of benzodiazepine withdrawal symptoms that can range from mild to severe and include:

• Depressed mood
• Trouble sleeping
• Shakiness
• Sweating
• Stomach and muscle cramps
• Vomiting
• Seizures

While Restoril is safe for most people who take it as advised, people with a history of alcohol or drug use disorders may be at greater risk for addiction issues with Restoril.