Side Effects of Restoril (temazepam)

Restoril (temazepam) is a benzodiazepine used to treat anxiety. Restoril and other benzodiazepines act by enhancing the effects of gamma-aminobutyric acid (GABA) in the brain.

GABA is a neurotransmitter (a chemical messenger that nerve cells use to communicate with each other) that inhibits many of the activities of the brain. It is believed that excessive activity in the brain may lead to anxiety or other psychiatric disorders and that Restoril reduces the activity. Restoril also increases total sleep time. 

Common side effects of Restoril include:

• excessive sleepiness,
• dizziness,
• weakness, and
• unsteadiness.

Other important side effects of Restoril include:

• depression,
• loss of orientation,
• headache, and
• sleep disturbances.

Drug interactions of Restoril include alcohol or drugs that cause sleepiness, which can increase the effects of Restoril.

Restoril and other benzodiazepines have been associated with fetal damage, including congenital malformations, when taken by pregnant women in their first trimester. Restoril should be avoided during pregnancy. Use of Restoril by nursing mothers has not been adequately studied. Consult your doctor before breastfeeding.

The most common side effects associated with temazepam are: 

• excessive sleepiness,
• dizziness,
• weakness, and
• unsteadiness.

Other important side effects include:

• depression,
• loss of orientation,
• headache, and
• sleep disturbances.

During controlled clinical studies in which 1076 patients received Restoril at bedtime, the drug was well tolerated. Side effects were usually mild and transient. Adverse reactions occurring in 1% or more of patients are presented in the following table:

The following adverse events have been reported less frequently (0.5% to 0.9%):

Central Nervous System – anorexia, ataxia, equilibrium loss, tremor, increased dreaming

Cardiovascular – dyspnea, palpitations

Gastrointestinal – vomiting

Musculoskeletal – backache

Special Senses – hyperhidrosis, burning eyes

Amnesia, hallucinations, horizontal nystagmus, and paradoxical reactions including restlessness, overstimulation and agitation were rare (less than 0.5%).

The concomitant use of benzodiazepines and opioids increases the risk of respiratory depression because of actions at different receptor sites in the CNS that control respiration. Benzodiazepines interact at GABAA sites and opioids interact primarily at mu receptors.

When benzodiazepines and opioids are combined, the potential for benzodiazepines to significantly worsen opioid-related respiratory depression exists. Limit dosage and duration of concomitant use of benzodiazepines and opioids, and monitor patients closely for respiratory depression and sedation.

The pharmacokinetic profile of temazepam does not appear to be altered by orally administered cimetidine dosed according to labeling.

Drug Abuse And Dependence

Abuse and addiction are separate and distinct from physical dependence and tolerance. Abuse is characterized by misuse of the drug for non-medical purposes, often in combination with other psychoactive substances. Physical dependence is a state of adaptation that is manifested by a specific withdrawal syndrome that can be produced by abrupt cessation, rapid dose reduction, decreasing blood level of the drug and/or administration of an antagonist.

Tolerance is a state of adaptation in which exposure to a drug induces changes that result in a diminution of one or more of the drug's effects over time. Tolerance may occur to both the desired and undesired effects of drugs and may develop at different rates for different effects.

Addiction is a primary, chronic, neurobiological disease with genetic, psychosocial, and environmental factors influencing its development and manifestations. It is characterized by behaviors that include one or more of the following: impaired control over drug use, compulsive use, continued use despite harm, and craving. Drug addiction is a treatable disease, utilizing a multidisciplinary approach, but relapse is common.

Controlled Substance

Restoril is a controlled substance in Schedule IV.

Abuse And Dependence

Withdrawal symptoms, similar in character to those noted with barbiturates and alcohol (convulsions, tremor, abdominal, and muscle cramps, vomiting, and sweating), have occurred following abrupt discontinuance of benzodiazepines. The more severe withdrawal symptoms have usually been limited to those patients who received excessive doses over an extended period of time.

Generally milder withdrawal symptoms (e.g., dysphoria and insomnia) have been reported following abrupt discontinuance of benzodiazepines taken continuously at therapeutic levels for several months. Consequently, after extended therapy at doses higher than 15 mg, abrupt discontinuation should generally be avoided and a gradual dosage tapering schedule followed.

As with any hypnotic, caution must be exercised in administering Restoril to individuals known to be addiction-prone or to those whose history suggests they may increase the dosage on their own initiative. It is desirable to limit repeated prescriptions without adequate medical supervision.