The longer you have been taking a drug for, the more your body and brain will have adapted to it.
This means that if you have been taking a drug for more than two or three months and suddenly stop taking it, you may:
- experience withdrawal effects which may make you very ill
- become unwell again with your original problem
- find it hard to tell which of these is happening (see 'Withdrawal symptoms' for more information on this)
Although some people can stop taking medication all at once, with no ill effects, many people become very unwell if they do so. It's impossible to tell in advance, so everyone is advised to withdraw slowly.
If you reduce slowly, you give the brain time to adjust back to being without the drug. The time this takes depends on how long you have been taking the drug, for example:
- If you have been taking a drug for six months, you may find it takes another six months to come off it completely.
- If you have been taking it for 20 years, you can expect to have to reduce very slowly indeed (perhaps over a period of years) before coming off completely.
It is usually easier to come off a drug with a long half-life. Drugs with short half-lives are more likely to cause withdrawal effects. The half-lives of individual drugs are shown on the information page for that drug.
Choosing to stop suddenly
If you already have experience of coming off psychiatric medication suddenly and it was OK, you may choose to do this again.
Some people simply prefer to stop abruptly and put up with the withdrawal effects because they want to get it over with. This may be easier if your main withdrawal effects are physical. But if you find that your original mental health symptoms seem to be returning – as may happen, especially when stopping an antipsychotic – this can be very frightening, and it is advisable to withdraw more cautiously.
If you become agitated during withdrawal, your doctor may agree to prescribe a small amount of diazepam (Valium) for you to take if absolutely necessary. The simple fact that you have it, and can perhaps keep it to take tomorrow, may be all the reassurance you need while getting through the worst effects.
Some drugs are dangerous to stop suddenly if you have been taking them for more than two or three months. These include clozapine (an antipsychotic), lithium and benzodiazepine tranquillisers.
Unfortunately going 'cold turkey' has for the most part been absolutely catastrophic and in the last instance ended up with me taking the highest level of completely new medications.
Having to stop suddenly
In some circumstances, such as experiencing a rare life-threatening side effect, you may need to stop taking your medication immediately, with no chance for reducing slowly.
This would normally happen under medical supervision, usually in hospital, due to the seriousness of the adverse effect.
How much should I reduce the dose?
It is often suggested that you should start withdrawal by reducing your dose by 10 per cent (one tenth). For example, if you are taking something at 20mg per day, you would reduce your dose by 2mg and take it at 18mg per day for a few days. If you get on all right with this and do not develop any withdrawal symptoms, you can reduce by a further 2mg and take 16mg per day.
As you reduce the doses, you might need to reduce by smaller amounts (e.g. 10 per cent of the new dose you are now on). Many people find they are more likely to get withdrawal effects as they reach lower doses.
With a drug with a long half-life (more than 24 hours) you may be able to make a larger reduction to begin with, and go more slowly later on.
Accurately making very small dose reductions depends on your drug being available at different doses, or in liquid form. It also depends on your prescriber being willing to prescribe it to you in different doses or in liquid form.
Some people may suggest reducing a dose by spacing the doses out more – but if the drug has a short half-life this may cause big fluctuations in the drug levels in your body, and make the withdrawal problems worse.
Each dose reduction may cause side effects such as:
These are signs that you are reducing too quickly, and you should put the dose back up to the last level at which you were feeling OK. Your symptoms should then stop. When you feel ready, you can try reducing again, by a smaller amount. At each stage, make sure you are OK on the dose you have reached before reducing further.
You could make a chart showing how much of the drug you will be taking each day. This keeps the end goal in sight and helps you keep track of where you are in the reduction process. This may be something that a psychiatrist, doctor or pharmacist can help with. But the plan is always flexible, and you may find you need to adjust it as you go along.
Many people find that the hardest part of withdrawal is the last part, when you are on a very low dose and might feel that you can now just stop because such a small amount can't make much difference – unfortunately this is usually not the case.
Tablets are often scored across, which means it should be fairly easy to cut them in half. You can buy pill-cutters for this purpose from some pharmacies. But the smaller the dose reduction you want to achieve, the harder it is to be accurate when cutting tablets.
Some drugs come as rapidly dissolving tablets, which you can take in a drink. If you have these, you could make sure you always dissolve them in the same amount of water or juice each time, and then gradually reduce the amount you actually drink, perhaps using an oral dosing syringe (used for babies and pets – it doesn't have a needle). The smallest of these are calibrated to provide doses of less than 1ml.
If your medicine is in capsules, you may be able to open them and remove some of the contents – but you should be cautious about doing this because some drugs are irritating to the skin, and it may be difficult to be accurate with the dose.
A pharmacist may be able to advise you on the best way to do this; however some people think it is never a good idea.
Many medicines come in the form of a liquid as well as tablets and capsules. The liquid may be a solution, a suspension or a syrup.
With a liquid it is easier to make very small reductions, sometimes by gradually diluting the medicine.
The Patient Information Leaflet that comes with your medicine will tell you if it already contains purified water. If you want to dilute it, it’s a good idea to use bottled or filtered water rather than tap water. This prevents any chemicals in the tap water affecting the medicine.
As you get down to very low doses, it may be easiest to use an oral dosing syringe (see above).
But again, this method may not be accurate enough, and you may want to get help from a pharmacist with this.
If you are taking an antipsychotic as a depot injection (an injection into a large muscle every 2-4 weeks) there is usually no need for gradual withdrawal. This is because the drug is slowly excreted over a long period anyway, and withdrawal problems do not seem to occur.
Some doctors or other professionals may be concerned if you say you wish to stop the injections, and may try to dissuade you. However it should usually be your choice whether or not you accept medication in this form.
What if I take more than one dose per day?
If you are coming off a drug that you take more than once a day, start by reducing just one dose. Which dose you reduce first partly depends on the type of drug; for example, if it’s a drug that makes you sleepy, you might want to start by reducing the dose you take in the morning.
Some people reduce by cutting out doses entirely. Depending on the half-life of the drug, this may cause fluctuations in the level of drug in your blood, which may increase withdrawal symptoms. In this case, it may be more manageable to gradually reduce each dose.
What if I take more than one drug and want to come off all of them?
It’s usually best to come off your drugs one at a time.
Which drug to start reducing first depends on what they are prescribed for, and how long you have been taking them. This is something to consider on an individual basis, preferably with the help of a professional.
But if you are taking one drug to help with the side effects of another, it’s best to reduce the original drug first, before coming off the drug for side effects. For example, if you are taking an anti-Parkinson’s drug to control unwanted side effects from an antipsychotic, it’s best to reduce the antipsychotic first before coming off the anti-Parkinson’s drug.
Drugs often affect how other drugs work. So if you take different types of drugs at the same time, you will probably have had the doses adjusted to allow for these effects. This means that you need to be very careful when reducing one drug, as the levels of another may change.
For example, imagine someone was taking carbamazepine (a mood stabiliser) with olanzapine (an antipsychotic). Carbamazepine changes the rate at which the body deals with olanzapine, so if they withdraw carbamazepine first, their dose of olanzapine would probably need adjusting.
It would be advisable to ask your doctor or a pharmacist about possible interactions between your medications, as well as reading the Patient Information Leaflet.
This information was published in July 2016. We will revise it in 2019.