TREATMENTS FOR DEPRESSION

Drugs known as antidepressants

DRUG:- MIRTAZAPINE

Zispin SolTabs are a melt-in-the-mouth preparation and are replacing the ordinary tablets in the UK. The old brown tablets were discontinued in March 2004, but generic versions are now available as well. The liquid is a special made by Rosemont.

What is mirtazapine used for ?

Antidepressants are used to improve mood in people who are feeling low or depressed. There are many other antidepressants. All these drugs seem to be equally effective at the proper dose but have different side effects to each other. If one drug does not suit you, it may be possible to try another.

How does mirtazapine work ?

The brain has many naturally occurring chemical messengers (or "neurotransmitters"). Two of these are called serotonin (sometimes called 5-HT) and noradrenaline. Both are important in the areas of the brain that control mood and thinking. It is known that these chemical messengers are not as effective or active as normal in the brain when someone is feeling depressed. Mirtazapine increases the amount of these chemical messengers in the brain. This can help correct the lack of action of these messengers and help to improve mood. For a more detailed explanation (ready in a few days), click here.

How should I take my mirtazapine ?

The tablets should be swallowed with at least half a glass of water whilst sitting or standing. This is to make sure that they reach the stomach and do not stick in the throat.

When should I take it ?

Take your medication as directed on the medicine label, usually once a day, at bedtime. Try to take it at a regular time each day. Taking it at mealtimes may make it easier to remember as there are no problems about taking this drug with or after food. Although you may take it at bedtime and it may help you sleep, mirtazapine is, however, not a sleeping tablet.

How long will mirtazapine take to work ?

It may take as long as two weeks before mirtazapine starts to have any effect on your mood, and a further three or four weeks for this effect to be reaching its maximum, especially if you are older.

How long will I need to keep taking mirtazapine for ?

This should be discussed with your doctor as people respond differently. Some people may need to continue taking it for months or even years. It is usually necessary to take it for at the very least a month after you have got completely. Usually it is best to take it for at least 6 to 12 months after you recover, to make sure you are fully over your illness. If you have been depressed more than once, it is best to keep taking an antidepressant for several years as this will reduce the chance of you becoming ill again.

Is mirtazapine addictive ?

Mirtazapine is not thought to be addictive, but if you have taken it for six weeks or more you may experience some mild "withdrawal" effects if you stop it suddenly (see next question). For further discussion, also click here.

Can I stop taking mirtazapine suddenly ?

It is unwise to stop taking mirtazapine suddenly, even if you feel better. Your depression can return if treatment is stopped too early. You might also theoretically experience some mild withdrawal symptoms such as fatigue, feeling sick and dizziness. When the time comes your doctor will usually suggest you withdraw the drug slowly e.g. by reducing the dose every few weeks. You should discuss this with your doctor.

What should I do if I forget to take a dose ?

Start again as soon as you remember unless it is almost time for your next dose, then go on as before. Do not try to catch up by taking two or more doses at once as you may get more side-effects. You should tell your doctor about this next time you meet. If you have problems remembering your doses (as very many people do) ask you pharmacist, doctor or nurse about this. There are some special packs, boxes and devices which can be used to help you remember.

What sort of side-effects might occur ?

Table adapted from UK Psychiatric Pharmacy Group leaflets, with kind permission (www.ukppg.org.uk )

Do not be worried by this list of side effects. You may get none at all. There are other rare side-effects. If you develop any unusual symptoms ask your doctor about them next time you meet.

Will mirtazapine make me drowsy ?

This drug may make you feel a little drowsy, particularly for the first week. This should then wear off. You should not drive (see below) or operate machinery until you know how it affects you. You should be careful as it may affect your reflexes reaction times. It is not, however, a sleeping tablet, although if you take it at night it may help you get to sleep.

Will mirtazapine cause me to put on weight ?

A few people can gain weight on mirtazapine. If you have problems with your weight, your doctor can arrange for you to see a dietician for advice, or consider switching to another drug.

Will it affect my sex life?

Drugs can affect desire (libido), arousal (erection) and orgasmic ability. Mirtazapine is not thought to have a significant effect on any of these.

Can I drink alcohol while I am taking mirtazapine ?

You should avoid alcohol while taking these drugs as it may make you feel more sleepy. This is particularly important if you need to drive or operate machinery and you must seek advice on this.

Are there any foods or drinks that I should avoid ?

You should have no problems with any food or drink other than alcohol (see above).

Will mirtazapine affect my other medication ?

You should have no problems if you take other medications. The only problem seems to be with some treatments to help sleep e.g. benzodiazepines etc. These can make you feel sleepier. There has been much concern about the safety of St. John's wort with antidepressants. Until more information is available, you should avoid taking St. John's wort along with any other antidepressant.

If I am taking a contraceptive pill, will this be affected ?

It is not thought that the contraceptive pill is affected by this drug.

What if I want to start a family or discover I'm pregnant?

It is important to consider that there will be a risk to you and your child from taking a medicine during pregnancy but also a possible risk from stopping the medicine e.g. getting ill again. Unfortunately, no decision is risk-free. It will be for you to decide which is the least risk. All we can do here is to help you understand some of the issues, so you can make an informed decision. For your information, major malformations occur "spontaneously" in about 2-4% of all pregnancies, even if no drugs are taken. The main problem with medicines is termed "teratogenicity" i.e. a medicine causing a malformation in the unborn child. A medicine causing teratogenicity is called a "teratogen". Since a baby has completed it's main development between days 17 and 60 of the pregnancy (the so-called "first trimester") these first 2-16 weeks are the main concern. After that, there may be other problems e.g. some medicines may cause slower growth. The infant may also be affected after birth e.g. withdrawal effects are possible with some drugs.

If possible, the best option is to plan in advance. If you think you could become pregnant, discuss this with your doctor and it may be possible to switch to medicines thought to carry least risk, and take other risk-reducing steps e.g. adjusting doses, taking vitamin supplements etc. If you have just discovered you are pregnant, don't panic, but seek advice from your GP within the next few days if possible. He or she may also want to refer you on to someone with more specialist knowledge of your medicine.

Very few medicines have been shown to be completely safe in pregnancy and so no manufacturer or advisor can ever say any medicine is safe. They will usually advise not to take a medicine during pregnancy, unless the benefit is much greater than the risk. In the UK, there is the NTIS (National Teratology Information Service) who offer individual risk assessments. However, their advice should always be used to help you and your doctor decide what is the risk to you and your baby. There is a risk from taking the medicine and a risk should you stop a medicine e.g. you might become ill again and need to go back on the medication again. The advice offered here is just that i.e. advice, but may give you some idea about the possible risks and what (at the time of writing) is known through the medical press.

It may be helpful to know that in the USA, the FDA (Food and Drug Administration) classifies medicines in pregnancy in five groups:

Mirtazapine is classified as "C". There is no evidence available at the moment and so you should seek personal advice from your GP, who may then if necessary seek further specialist advice.

Will I need a blood test ?

You should not need a blood test, but your doctor may need to check your blood occasionally.

Can I drive while I am taking mirtazapine ?

You may feel drowsy or sleepy at first when taking this drug. Until this effect wears off or you know how the drug affects you, do not drive or operate machinery. You should be careful as it may affect your reaction times or reflexes.

It is against the law to drive, attempt to drive or be in charge of a vehicle when unfit, either through illness or from the side effects of medication. Under UK law, it is the drivers responsibility to let the DVLA and insurance company know if you may be "unfit" to drive. If you do not, and you have an accident, it could effect your insurance cover. Your doctor will be able to advise you, and may wish to access the UK Driver and Vehicle Licensing Agency (DVLA) guidelines website, which has the current DVLA guidelines on anxiety/depression, psychotic disorders, mania and other conditions. If your doctor advises you not to drive, and you continue to do so, the doctor can inform the DVLA directly, as he or she would be lawfully responsible were you to have an accident. Once told, the DVLA may wish to carry out an enquiry, but you are entitled to drive until there a decision is made.

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© 2005 Steve Bazire, Norfolk and Waveney Mental Health Partnership NHS Trust Users drug information text originally compiled by Stephen Bazire & Sarah Branch  Comments/Problems email WebMaster

Email your comments or feedback.
Several developments have been as a result of feedback from visitors.

No site can be entirely bias-free. No matter how hard someone tries, training and background will always influence your outlook. We have, however, tried to eliminate bias, and we hope you take these pages in the spirit in which they are provided i.e. a genuine attempt to inform, educate and support.

Information here is based on published data. References include the UK British National Formulary (BNF, published by the British Medical Association and Royal Pharmaceutical Society of Great Britain), Martindale (the extra pharmacopoea, published by RPSGB Pharmaceutical Press), Psychotropic Drug Directory (latest edition), Data Sheet Compendium (UK Manufacturers Data Sheets, published by the Association of British Pharmaceutical Industry), MicroMedex (an independent and extensive CD-ROM based drug information source), UK Psychiatric Pharmacy Group leaflets, Royal College of Psychiatrists advice and guidelines and the current medical literature. Thanks also to all those people who left e-mail comments, suggestions and requests, who have helped shape the site.  

Email your comments or feedback.
Many developments have been as a result of feedback from visitors.

No site can be entirely bias-free. No matter how hard someone tries, training and background will always influence your outlook. We have, however, tried to eliminate bias, and we hope you take these pages in the spirit in which they are provided i.e. a genuine attempt to inform, educate and support.

Information here is based on published data. References include the UK British National Formulary (BNF, published by the British Medical Association and Royal Pharmaceutical Society of Great Britain), Martindale (the extra pharmacopoea, published by RPSGB Pharmaceutical Press), Psychotropic Drug Directory (latest edition), Data Sheet Compendium (UK Manufacturers Data Sheets, published by the Association of British Pharmaceutical Industry), MicroMedex (an independent and extensive CD-ROM based drug information source), UK Psychiatric Pharmacy Group leaflets, Royal College of Psychiatrists advice and guidelines and the current medical literature. Thanks also to all those people who left e-mail comments, suggestions and requests, who have helped shape the site.