Diazepam (Valium) — NZ Medication Guide | KiwiMeds
✅ Reviewed by a Registered Pharmacist NZ | Last updated: May 2026 | This information is for educational purposes only and does not replace advice from your doctor or pharmacist.
What is Diazepam (Valium)?
Diazepam (brand name Valium) is a benzodiazepine — a medicine that acts on the central nervous system to reduce anxiety, relax muscles, and prevent seizures. It is a controlled drug in New Zealand due to its dependence potential.
What is it used for?
Diazepam is used short-term for severe anxiety and anxiety-related insomnia, muscle spasm (back spasm, tension-related spasm), alcohol withdrawal, and seizure management. It is NOT recommended for long-term use due to the high risk of tolerance, dependence, and addiction. Fully funded by Pharmac with strict prescribing controls.
How does it work?
Diazepam works by enhancing the effect of GABA — the main inhibitory neurotransmitter in the brain. By enhancing GABA activity, it reduces the excitability of neurons, producing calming, muscle relaxing, and anti-seizure effects.
How to take it
Diazepam should only be used as directed by a doctor, for the shortest time possible (typically no more than 2–4 weeks). Take at the lowest effective dose. Do not drive or operate machinery — sedation is significant. Do not drink alcohol while taking diazepam.
Common side effects
Common side effects include drowsiness and sedation (can be severe), dizziness, confusion (especially in older people), muscle weakness, impaired coordination, memory problems, and paradoxical agitation (especially in children and the elderly).
Serious side effects
Severe respiratory depression (very slow breathing) can occur, especially if combined with opioids, other sedatives, or alcohol. Seek emergency care if someone taking diazepam becomes very difficult to wake, has slow or difficult breathing, or is unresponsive.
Drug interactions
Diazepam should NEVER be combined with opioids (morphine, codeine, tramadol, oxycodone) — this combination greatly increases the risk of fatal respiratory depression. Alcohol significantly enhances sedation and respiratory depression risk. Other sedative medicines (antihistamines, antipsychotics) also enhance effects.
Things to avoid
Never drink alcohol while taking diazepam — extremely dangerous. Avoid driving or operating machinery. Avoid opioids if at all possible. Do not stop diazepam suddenly after regular use — withdrawal can be severe and dangerous (seizures, delirium). Gradual tapering under medical supervision is essential.
NZ-specific information
Diazepam is a Schedule 4 controlled drug in New Zealand — prescriptions cannot be repeated without a new prescription. The Misuse of Drugs Act governs its prescribing. Long-term benzodiazepine use is associated with significant harms — if you have been taking diazepam long-term, discuss a gradual reduction plan with your GP.
Frequently asked questions
Is diazepam addictive? Yes — physical dependence can develop after as little as 4 weeks of regular use. Psychological dependence is also common. Can I take diazepam occasionally for anxiety? Occasional use has lower dependence risk than daily use, but regular use for anxiety is not recommended — CBT and SSRIs are better long-term treatments for anxiety.
💬 Always talk to your pharmacist or doctor for advice specific to you.
Related medications
Related: Lorazepam, Zopiclone. Condition: Anxiety.
References & Further Information
The following New Zealand and international resources were used to inform this page: