Drug Interaction Title


There is a potential interaction between Valium (diazepam) and hydroxyzine. They should be used together cautiously and only if recommended by your doctor.

Interaction Details

Co-administration of Valium (diazepam) and hydroxyzine can potentiate the CNS (central nervous system) effects (e.g., increased sedation or respiratory depression) of either agent. Caution is recommended with this combination.

If used together, you may feel drowsy or more tired when taking these drugs together. It is important to not drive or operate machinery until you know how these drugs affect you. Discuss any new or worsening side effects with your health care provider.

While the most common effects of taking both together include sedation and dizziness, rarely, more serious side effects can occur, such as:

  • Breathing problems
  • Confusion
  • Urinary retention

There are cases where Valium and hydroxyzine can be used together, but again, should only be under the direction of your doctor.

Valium Info

Valium (diazepam) is a long-acting benzodiazepine, available in oral, parenteral, and rectal dosage forms.

It is indicated for the treatment of:

  • Anxiety
  • Acute alcohol withdrawal
  • Skeletal muscle spasm
  • Seizure disorders, including status epilepticus

Valium has a quick onset of action and a relatively long duration of action, although it can be dosed up to four times daily.

Hydroxyzine Info

Hydroxyzine is available in two separate brand name products:

  • Atarax (hydroxyzine hydrochloride)
  • Vistaril (hydroxyzine pamoate)

Hydroxyzine is classified as a piperazine antihistamine (H1-blocker), which is structurally related to meclizine (Dramamine Less-Drowsy).

Hydroxyzine is generally used for treating histamine-mediated pruritus (i.e. itching) or pruritus due to allergic conditions. It also is used as an alternative treatment for anxiety disorders (e.g., generalized anxiety) as it has sedative and anxiolytic effects.


  • Both Valium and hydroxyzine has CNS depressant effects. Taking them together can result in additive side effects.

  1. ClinicalKey: Diazepam Monograph. ClinicalKey (Subscription Required)
  2. ClinicalKey: Hydroxyzine Monograph. ClinicalKey (Subscription Required)
  3. Vistaril Prescribing Information. AccessFDA
  4. Valium Prescribing Information. AccessFDA