Mirtazapine
An antidepressant taken at night. Often causes drowsiness and a bigger appetite, which can help some people and be a problem for others.
Brand names
- Avanza (incl. SolTab, which melts on the tongue), Remeron, plus generic brands
How it works
It blocks alpha-2 receptors, boosting noradrenaline and serotonin release. Strong histamine blocking causes sleepiness and a bigger appetite. Mood usually improves after 2 to 4 weeks.
Used for
- Major depression (TGA-approved)
- Low doses for sleep problems: off-label, and not a first choice because of weight gain and next-day drowsiness
Side effects
How often, from the official product information. Bold = serious.
Very common more than 1 in 10
- Weight gain and increased appetite
- Drowsiness or sedation
- Headache
- Dry mouth
Common 1 in 10 to 1 in 100
- Odd dreams, confusion, anxiety
- Poor sleep, sluggishness, tremor
- Dizziness, memory problems
- Nausea, diarrhoea, vomiting, constipation
- Rash, joint, muscle or back pain
- Swollen ankles, tiredness
Uncommon 1 in 100 to 1 in 1,000
- Nightmares, agitation, restlessness
- Hallucinations, mania
- Pins and needles, restless legs
- Fainting, low blood pressure
- Numb mouth
Rare 1 in 1,000 to 1 in 10,000
- Aggression
- Muscle jerks
- Pancreatitis
- Raised liver enzymes
Frequency not known reported, rate unclear
- Bone marrow suppression
- Low sodium, suicidal thoughts
- Seizures, serotonin syndrome
- Severe skin reactions
- Muscle breakdown, sleepwalking
- Breast swelling or milk discharge
- Urine retention, prolonged erection
Get help urgently if
- Fever, sore throat or mouth ulcers (a blood test is needed to check white cells)
- Fever, shaking, muscle jerks, confusion or a racing heart (possible serotonin syndrome)
- Thoughts of suicide or self-harm: Lifeline 13 11 14, or 000
- Yellow skin or eyes, a seizure, or a blistering rash
Good to know
- Take at bedtime. Driving: don’t drive until you know you’re not drowsy the next day.
- Avoid alcohol and other sedating medicines. Weight gain is common.
- Interacts with other serotonin medicines, some antibiotics and antifungals. Never combine with an MAOI.
- Stopping: reduce slowly to avoid dizziness, nausea, anxiety and poor sleep.
- Under 25s: suicidal thoughts can increase early on or after a dose change. Thoughts of self-harm: see your doctor now or call Lifeline 13 11 14.
- Pregnancy or breastfeeding: discuss with your doctor.
Information only. Not a recommendation or endorsement of any product. Whether a medicine suits you depends on your health and other medicines, so talk to your doctor or pharmacist. In an emergency, call 000.
More information
maladywise.com/medicines/mirtazapine/