Red flags — call us immediately or go to the Emergency Department if:
- Very hard to wake or limp (CNS depression)
- Breathing that seems very slow, irregular, or stops briefly (apnoea)
- Blue lips or pale/grey colour / universal RED
- Weak or absent sucking reflex at feeds
- Feeding progressively worse over several days (accumulation)
- Any seizure-like movements — universal RED
- A rash that does NOT fade when you press a clear glass on it — sepsis sign
- Fever in a baby under 3 months (any temperature ≥ 38.0 °C)
What clonazepam and lorazepam are
Clonazepam and lorazepam belong to the benzodiazepine family. They calm overactive electrical signals in the brain and nervous system. Clonazepam is used long-term for epilepsy and panic disorder; it stays in your body for a long time (half-life up to 50 hours). Lorazepam is used for short-term anxiety, acute panic, and sometimes acute seizures; it leaves the body faster (half-life 10–20 hours).
How much reaches your baby in breast milk
Both drugs pass into breast milk, but in small amounts. Lorazepam's relative infant dose is approximately 2–3 % of the mother's dose — considered low. Clonazepam's is similar per dose, but because it has such a long half-life, daily use can cause gradual build-up in the baby over time. Newborns and premature babies clear these drugs more slowly than older infants.
The key concern: infant sleepiness
The main thing to watch for is your baby being unusually sleepy, hard to wake, feeding poorly, or seeming limp. This is more likely in very young babies (under 4 weeks) and with long-term daily clonazepam. Most breastfed babies of mothers taking these medicines show no problems — but monitoring is important. If your baby's sleepiness has been gradually getting worse over days, contact your doctor promptly.
Short-term vs. long-term use
If you take lorazepam only occasionally (for example, one tablet during a panic attack), the risk to your baby is low. If you take clonazepam every day for epilepsy or chronic anxiety, the risk of accumulation increases. In this case, your prescribing doctor should be aware you are breastfeeding and review whether the dose and frequency are the minimum needed, or whether an alternative with less accumulation risk is possible.
Never stop benzodiazepines without medical advice
Stopping clonazepam or lorazepam suddenly can cause severe withdrawal — including seizures, severe anxiety, and insomnia. This is dangerous for you and indirectly for your baby. If you want to reduce your dose because of breastfeeding, speak to your GP, neurologist, or psychiatrist. They can guide a safe, gradual taper if needed.
If anything changes
Clonazepam and lorazepam pass into breast milk in small amounts. Watch your baby for unusual sleepiness, limpness, or feeding difficulties — especially in the first weeks. Never stop benzodiazepines abruptly without medical advice.
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Message us on WhatsAppReviewed and signed off by Dr Didier Decamps on 5 September 2026. This is general information and does not replace an individual assessment by a qualified clinician.
Written with AI assistance. Reviewed, corrected and signed by Dr Didier Decamps, paediatrician.
Last reviewed: 5 September 2026