Medicines You Should Never Stop Suddenly

People stop medicines for reasonable reasons — side effects, feeling better, running out, deciding they were never necessary. Most of the time nothing much happens.

For a specific list of medicines, stopping abruptly is genuinely dangerous, and the risk is often greater than anything the medicine itself was doing. This is that list, and what to do instead.

Steroid tablets — the most important one

Prednisolone and other steroid tablets taken for more than about three weeks must never be stopped suddenly.

Taking steroids switches off the body's own cortisol production. Stop abruptly and there is nothing to take over — which produces adrenal crisis: profound weakness, vomiting, abdominal pain, collapse and dangerously low blood pressure. It can be fatal, and it is entirely preventable.

• The dose must be tapered, on a plan from whoever prescribed it
• Carry a steroid emergency card — available from pharmacies, and it tells any clinician treating you what they need to know
• You need more steroid when ill, not less. The dose is usually doubled during fever or significant illness. If you are vomiting and cannot keep tablets down, that needs urgent medical attention

The same applies to anyone on long-term high-dose inhaled or injected steroids.

Beta blockers

Propranolol, bisoprolol, atenolol and similar drugs should be tapered, not stopped.

The heart adapts to being slowed. Remove the drug suddenly and there is a rebound — a racing heart, a rise in blood pressure, and in people with heart disease a genuine risk of angina, abnormal rhythms or a heart attack. The rebound typically arrives a few days after stopping, which is exactly when people have concluded nothing is going to happen.

Antidepressants

Two things need saying together.

They are not addictive — there is no craving, no escalating dose, no compulsive use. But stopping them abruptly commonly causes discontinuation symptoms, and dismissing that has done a great deal of harm to people's trust.

Those symptoms include dizziness, nausea, flu-like aches, irritability, vivid dreams, insomnia, and the sensory disturbances often described as "brain zaps". They are unpleasant and occasionally severe.

• Short half-life drugs are worst — paroxetine and venlafaxine particularly. Fluoxetine, with its long half-life, is much easier to stop
• Taper slowly, and slower at the end. Current thinking favours reducing by proportions rather than fixed amounts, with the final steps the smallest and slowest — the last part of the reduction is where most people struggle
• Liquid formulations and tapering strips exist for doses smaller than the available tablets allow. Ask
• Discontinuation symptoms are not relapse — they usually begin within days and improve if the dose is restored, whereas relapse takes weeks and looks like the original illness. Distinguishing them properly matters

Benzodiazepines and sleeping tablets

Diazepam, lorazepam, zopiclone, zolpidem and similar drugs must be tapered very slowly after regular use.

Abrupt withdrawal can cause severe anxiety, tremor, confusion, hallucinations and seizures — which can be life-threatening. This is one of the few withdrawal states that can kill directly.

Reduction is measured in months rather than weeks, and there is no prize for going quickly.

Anti-epileptic medicines

Stopping suddenly can provoke seizures, including in people who have been seizure-free for years.

This applies even when the drug was prescribed for something else — gabapentin, pregabalin, carbamazepine and others are widely used for nerve pain, anxiety and mood, and the withdrawal risk does not disappear because the indication was different. Gabapentin and pregabalin also cause a distinct and difficult withdrawal of their own.

Anticoagulants and antiplatelets

Warfarin, apixaban, rivaroxaban, clopidogrel and aspirin prescribed after a cardiac event should not be stopped without advice. The risk being prevented — stroke, clot, stent blockage — does not pause.

This is especially critical after a recent coronary stent. Stopping antiplatelet treatment early can cause the stent to block, which is a life-threatening emergency. If a dentist or surgeon asks you to stop, that should be checked with your cardiology team rather than assumed.

Opioid painkillers

Withdrawal from codeine, morphine, oxycodone and tramadol is deeply unpleasant rather than usually dangerous — but there is one lethal trap.

Tolerance falls quickly after stopping. Restarting at the dose you were previously taking, after even a short break, can cause a fatal overdose. This is the mechanism behind a great many opioid deaths, and it is not widely understood.

Others worth knowing

• Clonidine — causes severe rebound high blood pressure if stopped abruptly
• Lithium — abrupt cessation sharply raises the risk of relapse, more so than a gradual reduction
• Antipsychotics — relapse and withdrawal effects; taper
• Thyroid medication and adrenal replacement — these are replacing something your body should be making. They are not optional
• Insulin — never stop it because you are unwell and not eating. Illness raises blood glucose even without food, and stopping insulin during illness is a leading and entirely preventable cause of diabetic ketoacidosis
• Omeprazole and lansoprazole — stopping abruptly causes rebound acid production and a fortnight or so of worse symptoms than you started with. Not dangerous, but it explains why so many people conclude they cannot manage without them. Taper, and use an antacid through the rebound

When you should stop straight away

The advice above is not absolute. Stop and seek urgent help immediately for:

• Swelling of the lips, tongue or throat, or difficulty breathing — particularly on an ACE inhibitor such as ramipril, which can cause this months or years into treatment
• A widespread rash with blistering, peeling skin, or sores in the mouth, eyes or genitals, especially with fever
• Severe muscle pain and weakness with dark urine on a statin
• Any suspected severe allergic reaction

What to do instead of stopping

If a medicine is causing problems, the answer is nearly always a conversation rather than a decision made alone.

• Ask for a tapering plan in writing, with dates and doses
• Ask whether a liquid or smaller-strength preparation exists if the tablets do not divide small enough
• Ask your pharmacist — they are expert in exactly this and are considerably easier to reach than a GP
• Say plainly why you want to stop. "This is affecting my sex life", "I cannot afford it", "I do not think it is working" are all legitimate reasons, and there are usually alternatives
• Ask which of your medicines have sick day rules — the ones to pause during vomiting or diarrhoea. Ask while you are well, not while you are ill

And if you have already stopped something on this list, say so. Nobody is going to tell you off, and it is far more useful for a clinician to know than to spend the appointment puzzling over why things have changed.